is.1141.1993 seasoning of timber

8/12/2019 Is.1141.1993 Seasoning of Timber

1/33

Disclosure to Promote the Right To Information

Whereas the Parliament of India has set out to provide a practical regime of right to

information for citizens to secure access to information under the control of public authorities,in order to promote transparency and accountability in the working of every public authority,

and whereas the attached publication of the Bureau of Indian Standards is of particular interest

to the public, particularly disadvantaged communities and those engaged in the pursuit of

education and knowledge, the attached public safety standard is made available to promote the

timely dissemination of this information in an accurate manner to the public.

!"#$% '(%)

!"# $ %& #' (")* &" +#,-.Satyanarayan Gangaram Pitroda

Invent a New India Using Knowledge

/0)"1 &2 324 #' 5 *)6Jawaharlal Nehru

Step Out From the Old to the New

7"#1&"8+9&"), 7:1&"8+9&")Mazdoor Kisan Shakti Sangathan

The Right to Information, The Right to Live

!"# %& ;


2/33


3/33


4/33

( pm s;T m )hi di an. St andard

SEASONING OF TIMBER - CODE OFPRACTICE. ( Second Rev i si on

UDC 674@7*006*76

@ BIS 1993BURE U OF INDI N ST ND RDSMANAK BHAVAN, 9 BAHADUR SHAH ZAFAR MARGNEW DELHI 110002

ciober 1993 Prim Grog 10

( Reaffirmed 2004 )


5/33

Timber Sectional Committee, CED 9

FOREWORDThis Indian Standard ( Second Revision ) was adopted by the Bureau of Indian Standards, afterthe draft finalized by the Timber Sectional Committee had been approved by the Civil Engineer-ing Division Council.Seasoning is the first step in the efficient utilization of timber, especially in this country, wherethe climatic conditions are very trying for wood work, and where several commercially impor-tant species of wood are hard, heavy and liable to develop defects during drying and in use,unless carefully seasoned. It should be emphasized that all timbers, whether teak or otherspecies, naturally durable or non-durable need proper seasoning in order to give satisfactoryservice. Seasoning should be regarded as an integral part of timber utilization. With theincreased use of several secondary species that possess higher shrinkage than teak, padauk,deodar, rosewood, etc, it has become imperative that adequate attention should be paid to theprocess of seasoning of wood before use. This has been further necessitated also by the increas-ing availability of short rotation plantation wood of fast growing species under social/agroforestry programmes such as Eucalyptus hybrid, Acacia nil oti ca, Populus delt oides, Grevil l earobusta, etc.Freshly felled timber contains a large quantity of moisture, in many cases roughly 100 percentbased on oven-dry weight of wood, though in some light timbers the quantity of water in greencondition is twice as much as the weight of wood substance ( that is, roughly 200 percent ). Awell seasoned piece of wood should on the other hand contain about 10 to 12 percent moistureon an average. This would be in equilibrium with the atmospheric humidity in several parts ofthe country. This degree of seasoning is necessary for proper retention of shape and size ofcomponent parts of high class articles, such as cabinet work, railway carriages, panelling, etc.For rough work, and for outdoor uses, drying of timber, -say up to I5 to 25 percent moisturecontent, is considered enough. This also makes preservative treatment easy and effective.The process of drying timber, under more or less controlled conditions is called seasoning.During the course of the drying process, timber may develop defects and this is avoided by pro-viding adequate protection against unduly rapid drying condrtions, care in stacking and topweighting of the stacked timber. Timber shrinks during drying; the main objective of seasoningis to eliminate this shrinkage and the associated drying defects before use. Other advantagesare, increase in the strength and eIectrica1 resistance of timber, reduction in weight for trans-port purposes, improvement in wood-working qualities including gluing, painting and polishing,and a certain degree of protection from attack by insects and fungi depending upon the moisturecontent to which timber has been seasoned. Seasoned timber should be stored under coverprotected from rain and other forms of precipitation.Sawn timber for special purposes may be given an antishrink treatment and a recommendedmethod is given in Annex A.This standard was first published as tentative standard in 1958 and then revised in 1973. Apartfrom conventional seasoning processes, namely air and kiln seasoning, this second revision alsodetails certain special seasoning processes and preseasoning treatments that may be adopted toreduce drying times, costs and defects, conserve energy or avoid pollution. This revision alsoincorporates guidelines on the technique of sawing of logs of certain species containing severegrowth stresses to minimize warping on the saw and to minimize surface cracking during subse-quent seasoning of the sawn timber.The composition of the technical committee responsible for formu ation of this standard isgiven in Annex E.For the purpose of deciding whether a particular requirement of this standard is complied with,the final value, observed or calculated, expressing the result of a test or analysis, shall berounded off in accordance with IS 2 : 1960 Rules for rounding off numerical values ( revised ).The number of significant places retained in the rounded off value should be the same as that ofthe specified value in this standard.


6/33

IS 1141 : 1993

Indian StandardSEASONING OF TIMBER-CODE OF

PRACTICE( Second Revision )1 SCOPEThis standard covers CIassification oftimbers for seasoning purposes; preliminarytreatment and storage; stacking practice; pre-seasoning treatment; seasoning methods; kilnschedules for seasoning different species oftimbers; pre and post-treatment seasoning; kilnoperation procedure; measures for control ofwarp; and inspection, transport and storage ofseasoned timber. General guidelines are alsoincluded for seasoning of bamboo.

NOTE - The design and construction of seasonmgkilns, recommended moisture contents for seasonedtimber and methods of determination of moisturecontent are covered in separate Indian Standards,namely, IS 7315 : 1974, IS 287 : 1993 and 1s 11215 :1991 respectively.2 REFERENCESThe following Indian Standards are necessaryadjuncts to this standard:

IS No.287 : 1993

401 : 1982707 : 1976

6313( Part 2 ) : 1981

7315 : 1974

11215 : 1991

Tit leRecommendations for maxi-mum permissible moisturecontent of timber used fordifferent purposes ( thirdrevi sion )Code of practice for preserva-tion of timber ( thi rd revi sion)Glossary of terms applicableto timber technology andutilization ( second r evi sion )Code of practice for anti-termite measures in buildings:Part 2 Pre-constructionalchemical treatment measures(first revi sion )Guidelines for design, installa-tion and testing of timberseasoning kilnsMethods for determination ofmoisture content of timberand timber products

3 TERMINOLOGYFor the purpose of this standard the definitionsgiven in IS 707 : 1976 shall apply.

4 CLASSIFICATION OF TIMBERS FORSEASONING PZJRPOSES4.1 For the purpose of seasoning, timbers shallbe classified into the following three classesdepending upon their behaviour with respect tocracking and splitting, and drying rate:

a) Class A : Highly refractoryb) Class B : Moderately refractory, andc) Class C : Non-refractory

4.2 Highly Refractory WoodsThese are slow drying and difficult to seasonfree from cracking and splitting. Examples areheavy structural timbers, such as sal ( Shorearobusta ) and laurel ( TerminaI ia alat a ).4.3 Moderately Refractory WoodsThese may be seasoned free from surface andend cracking within reasonable short periods,given a little protection against rapid dryingconditions. Examples are moderately heavyfurniture class of timbers, such as sissoo( Dal bergia sissoo ) and teak ( Tectona grandis ).4.4 Non-refractory WoodsThese may be rapidly seasoned free from surfaceand end cracking even in the open air and sun.If not rapidly dried, they develop blue stain andmould on the surface. Examples are light broadleaved ( hardwood) species for packing cases,such as semul ( Bombax spp. ) and salai( Boswell ia serrat u ), and all coniferous species.4.5 Classification of commercially importantIndian timbers into the above three classes isgiven in Annex B.5 DEFECTS FOR SEASONING PURPOSES5.1 For seasoning purposes, defects in timbershall be grouped as follows:

a) Drying defects, andb) Defects not associated with drying.

5.2 Drying defects develop in timber as a resultof drastic drying conditions, improper stacking,refractory nature of timber, irregular or non-1


7/33

IS 1141 1993homogenous grain and properties or abnormalgrowth. Examples of drying defects are endsplits, surface cracks, warping, internal cracks,case hardening and collapse. These may beminimized, if not prevented, in case of logs byproper storage and in case of sawn material byadopting proper methods of stacking and con-trol over drying conditions during seasoning.5.3 Defecls not associated with drying are gene-rally present in timber in the living tree whilesome like shakes may also develop on accountof shocks sustained in felling. Examples ofsuch defects are knots, heart and cup shakes,pith, brittle heart, pitch pockets, sloping, wavyor spiral grain, etc. Warping of green timberon the saw or splitting ahead of the saw ingreen planks containing the pitch, due to resi-dual growth stresses present in the log, are alsodefects of this type. Such defects cannot beeliminated but further damage to wood may beprevented or minimized in many cases byadopting proper sawing and seasoning proce-dures.6 PRELIMINARY TREATMENT ANDSTORAGE6.1 The process of drying starts as soon as thetree is cut. Control over drying is, therefore,to be exercised immediately. It is desirable toprotect the timber from the early green stageagainst rapid drying, caused by exposure to sunand hot winds.6.2 Prevention of Drying of LogsSeasoning of timber in the form of logs is notpossible in practice. If the logs cannot imme-diately be cut into planks and scantlings, theirdrying should be restrained by storing underwater which is popularly ( but erroneously )known as water seasoning. During water stor-age, the logs should be completely submergedunder water. If the water is stagnant as in thecase of artificial log-ponds, it should be changed,say once a fortnight, to remove the fermentingmaterial. The bark should be removed beforethe logs are stored under water. Logs mayalso be stored in sea water for comparativelyshorter periods, but such storage exposes themto the risk of attack by marine borers. In caseit is not possible to store logs under water theyshould be stored on land over raised founda-tions of masonry or durable or preservativetreated timber under shade. In species liableto excessive surface cracking and end splitting,the bark may be left on during storage to retardrapid drying. The practice, however, increasesthe hazard of insect attack in some cases andshould be adopted only where experience indi-cates that losses through cracking and splittingoutweigh those through insect attack. Before

stacking, suitable end coating ( see 6.3 ) andprophylactic preservative treatment conformingto IS 401 : 1982 should be given. Logs canalso be stored on land under water sprays afterdebarking. For this, they shall be stacked on araised cement-concrete platform under conti-nuous or frequently intermittent water sprays.The platform shall be suitably prepared so as toenable collection of the water drained off fromthe logs into a reservoir which shall be fittedwith necessary pipes, centrifugal pump andspray nozzles for lifting the water, its respray-in and recirculation. Suitable preservatives orinsecticides may, if required, be added to thewater or it shall be replaced with fresh water atsuitable intervals of time.

6.3 Thick sections of all timbers, and speciallyrefractory timbers, are subject to end splitting.This can be prevented or minimized by coatingthe ends of logs and thick sections of all timberswith some kind of moisture-proof compositionup to a distance of 80 mm from the ends.Costly half-wroughts for specialized wood pro-ducts, for which special selection of timber isusually made, should also always be end-coated, Some of the effective compositionsare mentioned below:

4b)44e)

f )g)

Thick coal tar,Rosin and lamp black ( IO : 1 ),Hardened gloss oil,Paraffin wax,Anti splitting-cum-preservative compoundof following composition:H.S.P. bitumen Mex R 115/15 37.5L.S.P. bitumen Mex R IO/20 12.5 1 partsCreosote-fuel oil ( 50 : 50 ) 5.0 bySoap-stone 10.0 massCinder ( boiler ash ) 15.0 J-_-lOO O---Bituminous solution in organic solvents,Bituminous solutions in kerosene withboiler ash, having following composition:H.S.P. bitumen 500 gKerosene 250 mlBoiler ash 100 g

Sl No. (a), (b), (d) and (e) are melted andapplied hot.Sl No. (c), (f) and (g) are brush coated.Sl No. (f) can also he sprayed.

6.4 Timber YardThe timber yard should be maintained underhygienic conditions. It should preferably belevel, have a direct approach to the main road

2


8/33

and be away from residential areas. The landshould be on a high level with proper drainage.It should be well-fenced to prevent cattle fromstraying inside ( so as to avoid dung which is asource of serious infection ). The layout ofthe yard should be such as to enable free move-ment of transport from one part to another. Ifthe yard is big enough, trolley lines should beprovided for easy movement of timber. Thestorage area for timber should be kept free ofweeds and debris that restrict air movementalong the ground surface, harbour fungi andinsects, and create a fire hazard when dry. Itshould be surfaced with gravel in order to res-trict weed growth. To protect the stack oftimber from direct sun, there should be somebig shady trees in the yard.6.5 Methods of Stacking6.5.1 Logs ( Aw ait ing Conversion )These should be stacked on foundation inclosed stacks in one or more layers. The endsof logs should be coated with an antisplittingcomposition ( see 6.3 ). Top protection againstdirect sun should be provided by shade of treesor a covering of rejected odd-sized planks( wherever available ) so arranged as to providesufficient overhang at both log ends.6.5.2 Rai lw ay SleepersIn order to provide to a certain extent, thedrying conditions suitable for the species oftimber either the one and nine ( see Fig. 1 )or the close crib ( see Fig. 2 ) method of stack-ing should be adopted. The one and ninemethod is suitable for moderately heavy timbers,particularly coniferous sleepers in hot climateand for heavy timbers, in moist climate. Allconiferous sleepers in northern India and non-coniferous sleepers in moist zones of southernIndia, West Bengal and Assam should be stackedby this method. The close crib method givesslower seasoning as it reduces the air circula-tion. This is recommended for stackingsleepers of refractory timbers in hot and drylocalities, such as sal in Ut.:ar Pradesh andBihar. The open crib method ( see Fig. 3 ) isa modification of close crib method allowingmore air circulation. The effect of drying oftimber by this method is almost the same as inthe one and nine method. This is not a com-mon method of stacking sleepers. Stacks, eachcontaining about 100 sleepers are recommended.The centre-to-centre distance of crossers shallnot exceed 1.5 m. These methods of stackingcan also be used for short lengths of thickscantlings.6.5.3 PolesAfter debarking, poles should be stacked eitherin closed heaps or with crossers. In case of

IS 1141 : 1993stacking in closed heaps, there should be alter-nate layers of butt ends and top ends at oneend of the stack so as to keep the two ends ofthe stack level ( see Fig. 4 ). In the case ofstacking with crossers some of the poles them-selves could be used as crossers. The centre-to-centre distance of crossers shall not exceed 3 m.6.5.4 Fence PostsThese should be stacked in open crib fashion inwhich the alternate layers of posts are at rightangles to each other leaving a space of about80 mm between adjacent posts in the layer. Aconvenient height of 3 m is recommended forsuch stacks ( see Fig. 5 ). The centre-to-centredistance of crossers shall not exceed I.5 m.6.5.5 BamboosThese should be stacked in closed heaps on thefoundations to any convenient height. Thereshould be vertical pillars fixed into the groundabout 2.5 m apart on the two sides of the stackrunning along the length. Bamboos may alsobe stacked on vertical wooden framework withhorizontal partitions to divide up the stack forrapid seasoning.6.5.6 Hori zontaI Stacking of Saw n Timber ( Ot herthan Rai lw ay Sleepers )6.5.6.1 FoundationsVertical_ pillars of treated timber or brickworkor concrete are integral parts of the foundation.They should be 3 000 mm% in cross-section and300 to 450 mm in height and should be spacedabout 1.2 m apart ( centre-to-centre ) along thelength and width of a stacking unit. Thelength of the unit should depend upon the lengthof material to be stacked. Adjoining stackingunits should be spaced at least 750 mm apartfor ease of stacking and proper air circulationon all the sides of the stacks. The gulleysbetween adjoining rows of stacks should bealigned with the wind direction in localitieswhere more or less a perennial wind directionobtains.6.5.6.2 Long beams of suitable cross-sections,say 100 mm x 100 mm and above, should beplaced above the foundation pillars to serve asa framework for the stacking of timber. Thesefoundation beams should be prepared fromstrong timbers which should be treated with asuitable wood preservative conforming toIS 401 : 1982.6.5.6.3 Scantl i ng and squares ( baul ks )These should be stacked with crossers 50 mm x40 mm in cross section kept 2.5 m apart. Thestacks should be raised to convenient heights,say up to 3 m. The ends shall be covered witha moisture-proof composition ( see 6.3 ). It isdesirable that the width of individual stacksdoes not exceed 2.0 m.

3


9/33

IS 1141 : 1993

FIG. 1 ONE-AND-NINE STACKING

FIG. 2 CLOSE CRIB STACKING

4


10/33

IS 1141 : 1993

FIG 3 OPEN CRIB STACKING

FIG 4 STACK OF POLES


11/33

6.5.6.4 Pl anks ( see Fig. 6 )The stacking should be done on level founda-tions of skids. Crossers should be of uniformthickness and cross-section, say 40 mm x25 mm for stacking planks up to 50 mm inthickness. The distance between the successivecrossers in the layer should be about 600 mmfor 25 mm thick planks. For thicker pIanks,the spacing may be increased to 750 mm. Incase of very thin planks or species prone towarping, the spacing may be reduced to 450 mm.The crossers should be in vertical alignment ina stack. In the case of mixed lengths, thelongest planks should be at the bottom and theshortest ones on the top. The stacking shouldbe done under a shed to protect the timberagainst sun and rain. Heavy wooden beams,steel rails or concrete slabs should be placed atthe top to minimize warping. It is desirablefrom the point of view of uniformity of dryingthat the width of the stacks should not exceed1.5 m but if it does, an open space called flueor chimney about 250 mm wide should be left inthe middle of the width from top to bottom topermit good air circulation in the centre of thestack. Gaps about 25 mm should also be leftbetween adjoining planks in all the layers toallow free vertical movement of air.6.5.6.5 Top weighting should be uniformly dis-tributed over the stack and should act through

FIG. 5 STACKOF FENCEPOSTSa top layer of crossers and not directly over thetop layer of planks. A minimum weighting of380 kg/m2 is recommended for control of warpand cup.7 MOISTURE CONTENT OF SEASONEDTIMBER FOR DIFFERENT USES7.1 The final moisture content to which timbershould be seasoned before use depends uponservice requirements of the finished article andthe climatic conditions of the locality where itis to be used, and should conform to IS 287 :1973. The permissible limits of moisturecontent and the tolerances recommended inthese limits for seasoned timber for differentuses in the four climatic zones into which thecountry has been divided for this purpose isgiven in IS 287 : 1993 and methods of determi-nation of moisture content have been laid downin IS 11215 : 1991.8 SEASONING METHODS8.1 Seasoning methods should be classified asfollows:

a) Air seasoning; andb) Kiln seasoning.

.6


12/33

BRICK PILLAR

FIG. 6 HORIZONTALSTACKINGOF PLANKS FORAIR SEASONING8.2 Air Seasoning8.2.1 Sawn material for air seasoning should bestacked under shade, preferably in a shed.Three-recommended standard designs of shedsare described in 8.2.1.1 to 8.2.1.3.8.2.1.1 Shed Type 1It consists of a roof with walls on all four sides,with gates at the two ends for the moment oftimber. Adjustable shutter should be providedtowards the top and bottom of the walls tocontrol ventilation ( see Fig. 7A ). This typeof shed is suitable for seasoning and storage ofrefractory timber in hot and dry climate such assal ( Shorea robusta ) and laurel ( Terminaliaalat a ) in northern India.8.2.1.2 Shed Type 2It consists of a roof with walls on three sides,north side being open ( see Fig. 7B ). This issuitable for moderately refractory timbers liketeak ( Tectona grandis ) and rosewood ( Dalber-gia lat i fol ia ) practically all over India, exceptin very moist climate.8.2.1.3 Shed Type 3It consists of a roof supported on pillars, allsides being open ( see Pig. 7 C ). This is suitable

for refractory and moderately refractory timbersin very moist climate, and non-refractory tim-ber in a dry climate.8.2.2 The width of air seasoning sheds shallpreferably be limited so to accommodate notmore than two parallel rows of stacks plus thewidth of the intervening passage for movementof timber. The walls of the shed can be madeof brick, durable or treated timber planks orasbestos cement sheets or treated bambooreinforced lime and mud plaster walls. Timbercan also be used for the columns. For the roofCGI sheets with or without a covering of trea-ted wood shingles or corrugated asbestoscement sheets or compressed preservative andfire-retardant treated thatch boards can be used.CGI sheets, when used without covering,should be at least 2.4 m to 3-O m above the topof the stacks to minimize heat radiation to thetimber from the roof, or else, a ceiling shouldbe installed below the sheet roofing to cut offradiation. A pucca floor should be provided.At the time of doing earthwork anti-termitemeasures shall be adopted [see IS 6313( Part 2 ) : 1981 1. The roof should have suffici-ent overhang on all sides to prevent direct sprayof rain water. Proper drainage should be pro-vided for the surrounding ground.

7


13/33

IS 1141 1993

7A SHED TYPE t

79 SHED TYPE 2

7C SHED TYPE 3 -

8.2.3 For protecting timber from insect attackand decay during storage and seasoning asuitable prophylactic treatment conforming toIS 401 : 1982 should be given.8.2.4 Air seasoning is usually a slow process.The actual period required will vary with thesize and species of timber and the seasonalvariations of climate. Ordinarily, timber shouldnot be considered as fully air seasoned in lessthan six months. Planks of broad leaved species( hardwoods ) 25 mm in thickness may takethree to four months to season in a moderateclimate. Scantling as used for door and windowframes may take from 6 months to a year toattain reasonable degree of seasoning.8.3 Kiln Seasoning8.3.1 Kiln seasoning is a quick method ofseasoning timber to the desired moisture con-tent. Conditions best suited to each timber canbe given, thus keeping the degrade withinreasonable limits, while hastening the dryingoperation itself. For large scale production ofseasoned timber, kilns have become almost anessential adjunct to many timber industries.Kilns are also indispensible for seasoningtimber to low moisture contents for specialuses, which cannot be attained in humid

PLAN

FIG. 7 AIR SEASONINGSHEDSclimates by air seasoning. Seasoning kilns arealso used for sterilization of timber againstinsects and decay.8.3.1.1 The seasoning kiln is a chamber equip-ped with arrangements for heating andhumidifying the drying air to desired conditionsof temperature and relative humidity and itscirculation over the surfaces of timber stacked,inside. Steam is generally used for heating andhumidifying the air in seasoning kilns, thoughelectrical heating and furnace gases are alsosometimes used for supplying heat and forgeneration of the water-vapour necessary forhumidification of the kiln air. In modern kilnsfans are used for rapid circulation of air. Insome older types of kilns, circulation is onlythermal.8.3.1.2 An efficient seasoning kiln for dryingtimber within the minimum possible timeconsistent with minimum of seasoning defectscalls for certain minimum requirements withregard to relative humidities that can beattained and the uniformity of drying conditionswithin the kiln ( IS 7315 : 1974 ). Lack of anefficient humidifying arrangement exposes thetimber to increased degrade through crackingand splitting, as also makes case hardening

8

SIDE VIEW

SIDE VIEW


14/33

IS 1141 1993relief impossible particularly in refractorytimbers. Non-uniform drying conditions lead tohuge moisture content differences in the stocktowards the conclusion of drying run, entailingtime consuming and uneconomical equalizingtreatments and making uniform relief of casehardening stresses extremely difficult, if notpossible.8.3.2 Ki ln Operat ion8.3.2.1 Crossers for stacking timber in kilnsshall be 30 mm to 35 mm wide and 15 mm to25 mm thick, except in thermal circulationkilns where crosser thickness shall not be lessthan 25 mm. They shall be made from sound,seasoned timber of moderately strong species.All crossers in any one charge shall be ofuniform thickness.8.3.2.2 Crossers shall be aligned in verticalrows directly over foundation beams ( crossbearers ) placed on the kiln floor across thestack of timber. They shall be spaced along thestack at intervals adequate to prevent warpingof the timber in the kiln charge. However, thespacing shall not exceed 750 mm.8.3.2.3 The sides of the stack shall be planeand vertical, with no projecting edges of planks,as far as possible. The stack shall be made tofill out the entire length and height of thestacking space. Any gaps in length and heightshall be suitably blocked by baffles to preventshort-circuiting of air circulation via these gaps.The stack shall be sufficiently weighted on thetop to prevent warping of the top layers ( see6.5.6.5 ). Any gaps inevitably left betweenadjoining timbers in different layers shall alsobe randomly distributed within the stack toprevent short circuiting of air flow.8.3.2.4 The composition of any one kiln chargeshall be limited to timbers requiring the samedrying schedule ( see 8.4 ) and having thesame drying time.8.3.2.5 Kiln samples shall be chosen from thethickest, wettest and slowest drying stock inthe kiln charge or the combination thereofmost difficult to dry in the light of data onrefractoriness and drying schedules given inAnnex B. In general, heartwood samples wrthslow drying characteristics shall be preferredto sapwood. Samples so chosen shall be usedfor selecting the drying schedule to be emplo-yed and for regulating the drying conditions atdifferent stages during the run. However, wherestock with widely differing initial moisturecontents or drying times is mixed together in akiln charge, it is sound practice also to keepextra samples of the driest and fastest dryingpieces in the charge in order to follow their

moisturecontent condition. These samples shall,however, not be used for regulating dryingconditions in the kiln.8.3.2.6 All kiln samples shall be selected freefrom knots and other natural defects. Samplesshall be prepared in the manner set out inAnnex C.8.3.2.7 The number of kiln samples used perkiln charge shall be adequate to provide thekiln operator with sufficient data of the dryingprogress throughout the length and height ofthe charge, but as a minimum, there shall beone sample each on the entering and the lea-ving air sides of the timber stack to any 1.5 mof stack length and height. The samples shallbe dried along with the stack of timber andshall be distributed evenly along its length andheight as specified in Annex C.8.3.2.8 To ensure minimum of drying defectsconsistent with a reasonably short dryingpericd, it is necessary to ensure that the correctdrying schedule be selected. When more thanone species or thicknesses or material havingwidely diRerent moisture contents are driedtogether in a charge, the drying conditionsshall suit the stock needing the mildest dryingschedule and shall be varied in accordancewith the moisture content condition of the kilnsamples -prepared from such stock ( see8.3.2.5 ). Drying schedules shall not be usedwhich:

a) appreciably reduce the strength of tim-ber, andb) cause severe or uneven darkening whichwould not be removed from the timberby a normal planing operation.

8.3.2.9 When large variation in moisturecontents between individual kiln samples placedtogether in a kiln charge is observed in thefinal stages of drying, a conditioning treatmentat a suitably chosen relative humidity conditionshall be given for an adequate period tominimize the moisture content differencebetween the kiln samples as also within theircross-section so as to be within specified limits( see 8.3.2.13 ).8.3.2.10 A check test shall be made at theconclusion of drying for average moisturecontent, moisture content distribution in thesection and case hardening in all the kilnsamples following the methods laid out inAnnex D.8.3.2.11 When necessary to prevent deteriora-tion by checking, the kiln charge shall beallowed to cool inside the kiln to within 15 to20oC of the outside temperature before removal.

9


15/33

IS 1141 19938.3.2.12 During the drying time of each kilncharge, records shall be taken of the followingdetails:

a)

b)c)d)e)

Dry and wet bulb temperatures of theentering air. These temperatures shall bepreferably recorded continuously ( if arecorder is available ) or in any case atregular intervals not exceeding one hour.Recording shall also be made at everychange of conditions in the kiln and atthe time of stopping and starting forintermittent operation;Any stoppage of fans or other kiln partsor the wet bulb water supply, the steamsupply, or any other operation;Details of weighings and calculationsmade in the preparation of kiln samples;Details of periodic weighings and mois-ture content data of kiln sampIes to showprogress in drying; andDetails of check test.

8.3.2.13 Unless otherwise specified, a kilncharge shall be deemed to have been seasonedsatisfactorily if at the end of the kiln run ( a )the average moisture content of all the kilnsamples does not exceed 1 percent and themoisture contents of individual kiln samplesdoes not exceed 3 percent of the desired finalmoisture content, ( b ) the difference of mois-ture content between the whoIe section and thecore does not exceed 2 percent for timber,40 mm or below the thickness and 4 percentfor thicker timber, and ( c ) prongs preparedfrom the samples show no appreciable curvatureafter being allowed to room-dry for 24 hours,as determined by the procedure described inAnnex D.8.3.2.14 Start the conditioning treatment whenthe average moisture content of all the kilnsamples has been reduced to the value 1 percentless than the desired final moisture content. Atthis stage, the RH in the kiln shall be suitablyraised without altering the temperature thatwas being used in the last drying step of theschedule so that E. M. C. condition of the kilnair is 2 percent lower than the desired finalmoisture contentl. The treatment should becontinued till the moisture content require-ments of 8.3.2.13 are attained.8.4 Kiln Schedules8.4.1 The kiln drying schedule gives theconditions of temperature and humidity to be1)Refer Table on page 85 of Timber Drying Manualby G. H. Pratt, Her Majestrys 6tationary Office,London for EMC values under different temperatureand RH conditions.

maintained in a timber seasoning kiln forsatisfactory drying of timber. The seasoning oftimber is started at a comparatively lowertemperature and higher humidity.These conditions are gradually altered as thetimber dries, until towards the end of seasoningthe temperature of the air inside the kiln isfairly high and the umidity is low. The stea-ming treatmentsprescribed under each scheduleare meant to initially heat up the kiln chargeand inactivate mould growth at the start of thedrying run, to partially relieve drying stressesin timber at the intermediate stages and tocompletely relieve case hardening stresses atthe end of seasoning. For seasoning of Indiantimbers, schedules I to VII ( see aZso nnex B,and 8.4.5 to 8.4.11 ) are recommended.8.4.2 The temperature and humidity given inSchedules I to VII are meant for seasoning25 mm thick timber. For timber more than25 mm and up to 50 mm in thickness, the relativehumidity should be kept 5 percent higher at eachstage during seasoning. For timber 50 mm to100 mm thick preliminary air seasoning to about25 percent moisture content is recommended.This can be followed by kiln drying, if nece-ssary, with the same humidity conditions as for50 mm.8.4.3 The average moisture content of thewettest half of the total number of samples onthe side where air enters may be taken as aguide for making changes in the kiln schedulein preference to one single sample whichhappens to be the wettest. This refers to thestudy of rate of drying of timber and changesin kiln schedule to be made during kiln dryingof timber.8.4.4 The seasoning kiln can also be utilized forsterilization of timber, which is carried out byinitial steaming of the charge at a temperatureof 65C to 70C at 1 percent relativehumidity for timber above 30 percent moisturecontent and 80 percent relative humidity fortimber below 33 percent moi#ure content. Thetime for steaming should be 2 h for 25 mmthick timber. An additional period of heatingat the rate of one hour for increase of thicknessby every 12.5 mm over 25 mm is required.8.4.5 Schedule I covers species marked I in co14 of Annex B commonly used for packing casemanufacture.8.4.5.1 These timbers will take about 4 to 5days to season. Initial steaming of the chargefor about 2 h at 55C and 100 percent reIativehumidity should be carried out to kill mouldgrowth.

10


16/33

IS 1141 : 1993Schedule I for 25 mm Thick Planks of Species 8.4.8 Schedule IV covers species marked IV inMarked I in Annex B co1 4 of Annex B which include commonMoisture Content Temperature Relativeof the Wettest --.---A----\ HnmidityTimber of irInlet Side,Percent

(1)

Dry Bulb WetFIb PercentC(2) (3) (4)Green 52 44 62.0z :: :z 4405.0

z: 658 :: 33.59.0

t furniture timber.Schedule IV for 25 mm Thick Planks of SpeciesMarked IV in Annex B

Moisture Content Temperature Relativeof the WettestTimber on Air ----~Inlet Side, Dr 3ulb Wet BulbHp:y;zt;

CPercent(1) (2) (3) (4)Green 42 38.5 80608.4.6 Schedule II covers timbers marked 11 inco1 4 of Annex B commonly used for lightplanking or for moderately heavy type ofpacking cases.40353025Schedule II for 25 mm Thick Planks of Species 20

42 38 1645 40 7247 40 6449 40 5652 40 4755 40 39-arked II in Annex B

Moisture Content Temperature Relative8.4.8.1 These timbers will take 12 to 15 days to

of the Wettest r---_*--- ~ Humidity season. One intermediate steaming and oneTimber on Air Dry Bulb Wet Bulb Percent steaming towards the end of drying at 55CInlet Side, C CPercent and 100 percent relative humidity for 2 to 4 h(1) (2) (3) (4) would be required. For precision drying forGreen :; ii 12.0

high class work conditioning treatment should:: 64.0

be given.49 56.0

z: 53 :: 44.08.4.9 Schedule V covers species marked V in

58 40 32.5 co1 4 of Annex B used for furniture, construc-tional work or for certain special items, such8.4.6.1 These timbers will take about 5 to 7 as bobbins and other turnery articles.days to season. Initial steaming Of the chafgefor about 2 h at 55C and 100 percent relative Schedule V for 25 mm Thick Planks of Specieshumidity should be carried out to kill mould Marked V in Annex Bgrowth.. Moisture Content Temperature Relative8.4.7 Schedule 111 covers species marked III of the WettestTimber on Air r---7D;; Bulb Wet Bulb HumidityPercentin co1 4 of Annex B which include most light Inlet Side, Cfurniture timber. PercentSchedule III for 25 mm Thick Planks of SpeciesMarked III in Annex BMoisture Content Temperature Relativeof the WettestTimber on Air T--_-----Inlet Side, DrKcBulb Wet Bufi;

~e~~;:YCPercent

(1) (2) (3) (4)Green 42 38.5 8045 45 40 7235 46 40 6830 48 40 6025 50 40 5320 52 40 47

(1 (2) (3) (4) 15 55 40 39Green 38::

44t ; ::

74 8.4.9.1 These timbers will take about 13 to 166435 days to season. Some abnormal behaviour in30 :: :8 seasoning need to be watched for and careful25 5:20 55 :: 44 handling of the kiln would be necessary. In39 addition to the initial steaming; two interme-

8.4.7.1 These timbers will take about 8 to IO diate and one final steaming at 55C and 100days to season. In addition to the initial Stea- percent relative humidity for 2 to 4 h would beming, one intermediate steaming and one required for these timbers.steaming towards the end for 2 to 3 h at 55Cand 100 percent relative humidity would be 8.4.10 Schedule VI covers species marked VIin co1 4 of Annex B most of which are used forrequired. structural purposes and heavy planking.11


17/33

IS 1141 : 1993Schedule VX for 25 mm Thick Planks of SpeciesMarked VI in Annex BMoisture Content Temperature Relativeof the Wettest r__-_7 HumidityTimber on AirInlet Side, Dryzub Wetc?ulb Percent

Percent1)Green604035302520I9

(2) 3) 4)40 37 8242 38 7645 40 7246 40 6847 40 6448 40 6050 40 5352 40 47

8.4.10.1 These timbers will take about I6 to 20davs to season. Thev need slow and carefuldrying. The charge will have to be steamed atleast twice during the course of drying, inaddition to the initial and final steaming at55C and 100 percent relative humidity for 2 to4 h.8.4.11 Schedule VII covers species marked VIIin co1 4 of Annex B which include several heavyand highly refractory timbers.Schedule VII for 25 mm Thick Planks of SpeciesMarked VII in Annex B

Temperaturec_-_*--_~DrYulb We~c?ulb

Moisture Contentof the WettestTimber on AirInlet Side,Percent

1)Green604035302520I8I5

RelativeHumidityPercent

(2) 3) 4)40 38 8841 38 8242 38 1645 40 7246 40 6847 40 6450 42 6152 42 545s 42 45

12

8.4.11.1 These timbers will take about 24 to 30days to dry. The charge will need at least threeintermediate steaming operations in additionto initial and final steamings at 55C and 100percent relative humidity for 2 to 4 h.9 OTHER SEASONING METHODSApart from air and kiln seasoning, certainspecial seasoning methods have sometimesbeen adopted to reduce drying time, dryingdefects and/or seasoning costs, to conserveenergy and avoid pollution.

9.1 High Temperature and Superheated SteamDryingThis technique essentially consists in kilndrying of timber at temperatures in the vicinityor in excess of the boiling p3int of water adop-ting suitable RH reduction schedules. Dryingtimes are reduced several times compared tokiln drying under medium temperature schedules( see 8.4.5 to 8.4.11 ). Hardwoods generallysuffer severe warping, crook and collapse whendried green from the saw by this process.However, the process can be continuously usedfor quick drying without excessive degrade ofhardwood timber after partial air drying or lowtemperature predrying ( see 9.4 ) to about 30percent moisture content.9.2 Solar Drying9.2.1 Drying of timber can be appreciablyaccelerated compared to air seasoning and atappreciabIy reduced seasoning costs comparedto conventional steam heated kiln of suitabledesign. Solar kilns based on the greenhouseprinciple have been widely accepted in thecountry. Of the two designs of this type of kiln,namely, forced air circulation and thermalcircuIation designs, the former is better suitedfor rapid and uniform drying of timber withoutany degrade. This design is also provided witha water spray for additional humidificationrequired while drying thick and refractorytimber. It may be advantageously adopted forseasoning timber for end uses for which steamheated kilns are used. Solar kilns of capacityup to 50 m3 of tawn timber per charge havebeen in commercial use in the country.9.2.2 In the forced circulation solar heatedkiln, the entire energy input required in theform of heat for evaporation ofwater is derivedfrom soIar energy. Electric energy is required,only for driving the kiln fans. This results inconsiderable savings in overall process energyrequirement. Besides, the kiln is a pollution-free system.9.2.3 It is not possible to operate the schedulesgiven under 8.4 in a solar kiln because of theinherent diurnal variation of kiln temperature.However, certain degree of regulation of kilnRH is possible by use of the water spray andadjustment of kiln vents to prevent cracking inthe initial green stage of drying. The qualityof timber dried in the solar kiln is generallybetter than air seasoned timber, because ofbetter RH regulations possible in the solar kiln,and it approaches the quality of kiln driedtimber. Case hardening stresses can be relievedby prolonged water spray humidification afterthe drying is completed.


18/33

9.2.4 The solar kiln is normally operated duringdaylight hours only. A single-pass forced airdrying arrangement is incorporated making useof the dry air available on warm summer nights,which is effective during green stage drying.The solar drying periods are on the averagedouble of those in steam heated kilns but consi-derably less than periods required for airseasoning.9.2.5 Solar kiln temperatures have an inherenttendency to keep low during the green stagedrying and to increase gradually as the dryingprogresses. Temperature differential over theambient is around 7C at the start of a greencharge, gradually building up to 20C or moreat the completion of drying, on clear days. Thesolar kiln, therefore, needs much less skilledattendance than a steam heated kiln. Theperformance however suffers on continuouslycloudy days.9.3 Dehumidification Drying9.3.1 This is essentially a kiln drying processin which the water vapour from the kiln isremoved by condensing it as water on theevaporating ( cooling ) coil of a refrigeratingsystem with both evaporating and condensingcoils located within the kiln, rather than byventing it out as in the conventional steamheated kiln. The latent heat released on con-densation of water vapour is picked up by theliquid refrigerant which evaporates inside theevaporating coil. This heat is finally re-deli-vered to the kiln air as heat of condensation ofthe refrigerant vapour via the condensing coil,in which the refrigerant vapour is compressedand re-condensed as liquid. The considerableventing heat loss that occurs during drying in asteam heated kiln is thus avoided.9.3.2 This process, like solar drying, apprecia-bly conserves the component of energy used asheat compared to that involved in drying insteam heated kilns. Its operation, however,requires the entire energy input to be in theform of electric energy. The process lends it-self easily to automatic control of kiln con-ditions. This feature, together with the energysavings possible, is expected to make therunning costs of this process economicalcompared to steam heated kilns.9.3.3 The dehumidification equipment indi-genously available at present limits kiln operat-ing ternperatures to 50C. Drying times underthis process are, therefore, liable to be slightlylonger than in steam heated kilns.9.3.4 The quality of drying is somewhat betteras regards freedom from warping than in steam

I 1141 : 1993heated kilns, because of the lower temperaturesadopted. Case hardening stress can be relievedby prolonged water spray humidification as inthe solar kiln.9.4 Predrying or Forced Air Drying9.4.1 Predrying or forced air drying ( see also8.4.2 and 9.1 ) may be adopted for acceleratingthe partial air drying of timber to about 25 per-cent moisture content preparatory to kilnseasoning in order to reduce kiln periods andincreases kiln capacity, where climatic con-ditions are too humid or cold for air drying.The method consists in forcing unheatedatmosphericair or air heated to lowtemperatures( not exceeding about 42C ) through the timberstack by means of fans in a single pass or by arecirculating system. Low temperature predry-ing by a recirculating system is generallycarried out inside shed with lightly insulatedwalling. A solar kiln ( see 9.2 ) may also bevery effectively used for partial predrying.9.4.2 Predrying in conjunction with final dryingin steam heated kilns offers overall economicsin the drying operation compared to directdrying in steam heated kilns from the greencondition. Gains are expected to be most ifsolar kilns are used for predrying. Predryingis also recommended for timbers that aresusceptible to collapse and warping.9.5 Baking Over Open FireThis method is generally adopted for roundbamboo used for tent poles fishing rods, etc,in case of species used for these purposes. Theobject of this treatment is primarily to sterilizethe green bamboo to obtain benefit of slightformation of wood tar creosote and to reduceits surface moisture in order to provide primaryprotection against fungal discolouration anddecay in storage. The treatment may, however,be effective in this respect only for shortperiods under adverse storage conditions, unlessprophylactic preservative treatment conform-ing to IS 401 : 1982 is simultaneously given. Thebakingusuallydoes not reduce the bamboo to theequilibrium moisture content level, and there-fore suffices only for end-uses where subsequentchange of cross-sectional shape and size to acertain extent can be tolerated without affectingserviceability. For more exact requirements,baked bamboo shall be further air seasoned( see also 6.5.5 ).10 PRESEASONING TREATMENTSThese treatments given to the green sawn tim-ber prior to seasoning are aimed at reducingdrying times, drying defects and overall dryingcosts.

13


19/33

IS 1141:1993

10.1 Chemical Seasoning10 1 1 his technique can be successfully appliedto prevent cracking and splitting during season-ing of highly refractory hardwoods and thicksections for which these defects are founddifficult to avoid under conventional air andkiln seasoning. Green sawn timber is firstsoaked in solution of an anti-shrink or anti-shrink-cum-hygroscopic chemical for an appro-priate period, depending upon the species andthickness of section, so as to treat the outerlayers of the section by diffusion. The treatedtimber is then air or kiln seasoned.10.1.2 Any of the following chemicals or com-positions may be used for chemical seasoning,depending, upon the cost considerations inrelation to the end use:

a) Polyethylene glycol - 1 000 or 1 500,25 to 40% ( m/m ) solution at room tem-perature. Temperatures up to 45C maybe maintained to accelerate thetreatment.b)c)

Commercial fertilizer grade urea, 60%( m/m ) solution maintained at 45C.Urea-sorbitol soluticn, 16 : 24 : 5 ( water-urea-sorbitol ) by mass, maintained at45C.

10.1.3 For kiln drying of timber pre-treatedwith compositions given in 10.1.2 b ) and( c ), the appropriate schedule shall be selectedas per 8.4 except that the RH used in the firstdrying step of the schedule shal1 not exceed80 percent; for kiln drying of timber treatedwith composition 10.1.2(a), it may be safelypossible to adopt accelerated RH reductionschedules compared to those prescribed in 8 410 1 4 hemical seasoning can be advantagecus-ly adopted for half wroughts of rifle, furniture,shoe lasts, shuttles, handicrafts like fruit bowlsand statues, tool handles, tent mallets and alsofor door and window frames made from refrac-tory species such as Eucalyptus hybrid ( R.tereti corni s ), Termi nali a alat a, etc.10.2 Presteaming10.2.1 Steaming of green sawn timber at aimos-pheric pressure at temperature in the vicinityof 100C for 2 to 4 h can accelerate subse-quent air or kiln drying of some timber speciesof the moderately and highly refractory classes(see 4.3 and 4.2) such as Gmeli na arborea, Schima,w all ichii , Lannea coromandeli ca, Di pterocarpusspp., Shorea robusta, etc. Impermeable andmoderately permeable wood responds betterto this treatment than permeable wood, and the

radial planks better than the tangential. Steam-ing followed by quenching in cold water and hotwater treatment near 100C have also beenfound to be effective.10.2.2 Adoption of this pretreatment in com-mercial seasoning practice however needscareful preliminary trials, since it has been foundto enhance warping and collapse in subsequentkiln drying of some species.10.3 Special Sawing Procedures10.3.1 The broad faces of tangentially sawnplauks of most species suffer more surfacecracking than the broad faces of radially sawnplanks. Radial or quarter sawing may there-fore be adopted to advantage in case of larger-girth logs of highly refractory hardwoods suchas Eucalyptus hybrid ( E. tereticornis ) Quercusspp., Terminalia alata, etc, to reduce surfacecracking during seasoning. This sawing methodhowever appreciably reduces the width of planksavailable from logs of a given girth, besidesslightly reducing the volume yield and increas-ing sawing labour and time compared to con-ventional plain sawing.10.3.2 A balanced tangential sawing scheme forlogs, in which a discrete sawing sequence isadopted for successive planks ( see Fig. 8 ),has been found most successful in obtainingplanks of. uniform thickness with minimumbowing and crook on the saw, in the case ofspecies containing severe growth stresses in thelog such as Eucalyptus hybrid ( E. tereticornis ),Populus deltoides and Acacia auriculaeformis.This procedure may be useful to minimizegrowth stress induced bow and crook duringsawing of logs of such species.10.3.3 A saw-dry-rip procedure, found effectivein obtaining final cut sizes free from bow andcrook in some species containing severe growthstresses, such as Populus deltiodes, Heveabrazil iensis and Eucalyptus grandis, consists inflat sawing of the log into full-width thick flit-ches which are then seasoned. The seasonedflitches are finally converted into the cut sizesrequired. The larger width and thickness inwhich the flitches are seasoned are believed toassist in accommodation and ultimatereduction of the stresses. In some species likePopuhts deltoides rapid seasoning of the flitchesat high temperatures has been found practicaland effective without any increase of degrade,while in some others the Aitches may be air orkiln seasoned.11 PRETREATlMENT AND POSTTREATMENT SEASONING11.1 Timber intended to be treated with oil-

14


20/33

IS 1141 1993

FK. 8 BALANCED TANGENTIAL SAWING

type preservatives may be seasoned to the finalmoisture content levels ( see IS 287 : 1993 )before treatment.11 1 1 imber intended to be treated with watersoluble preservatives needs both pre- and post-treatment drying, first to dry it to the mois-ture content levels specified in IS 401 : 1982 forensuring proper absorption and penetration andsubsequently again to reduce the moisture con-tent to the final required levels. Air seasoningis preferable for the pre-drying preparatory topreservative treatment, and the final drying( after treatment ) may then be effected in airor in a kiln before the timber is manufacturedor fashioned to the desired shape and size. Inany case, the seasoning should not be carriedout under drastic conditions causing seriouslateral movement of the preservative outwardfrom inside. Post-treatment seasoning of tim-ber treated with water-soluble borax-boric acidcomposition shall be done in air, as kiln season-ing tends to result in partial loss of thesechemicals under high temperatures.11.1.2 Where timber is partially pre-air driedand roughly fashioned to required shape andsize preparatory to treatment with water solu-ble preservatives, the following precautions arerecommended:

a) Sufficient oversize should be left at therough fashioning stage to allow for shrin-

b) Post treatment seasoning shall be carriedout slowly to avoid cracks and end splitsin the fashioned timber. Besides, for endcoating of individual fashioned timberpieces immediately after treatment,sufficiently high RH may be adopted forthe initial steps in kiln drying.This procedure must be adopted only after

kage during post-treatment seasoning andfor moulding and machining operationsduring subsequent manufacture.

making preliminary trials on the timber speciesto be used, particularly if refractory species areused.12 INSPECTION OF SEASONED TIMBER12.1 Seasoned timber should be inspected forconformity to specifications of moisture con-tent, residual case hardening stresses, wherevernecessary, and natural as well as seasoningdefects.12.2 For inspection of a given lot of timberwith regard to moisture content and residualcase hardening stresses, test samples shall bedrawn which are representative of the lot indimensions, quality and moisture content. Thenumber of samples to be tested depends uponthe size of the lot, the permissible range ofmoisture contents ( which depends upon theend-use ), the composition of the lot and the


21/33

IS 1141 1993likely variation in moisture content between theindividual pieces. However, as a minimum,not less than 5 percent samples shall be selectedfor tests from any lot.12.3 Conformity to moisture content require-ments shall be determined in accordance withthe maximum permissible limits of moisturecontent and the tolerances recommended inthese limits for seasoned timber for variousend-uses, as laid down in IS 267 : 1993 andfollowing the testing procedure prescribedin IS 11215 : 1991.12.4 Seasoned timber shall be inspected forresidual case hardening stresses, wherever it is&ended to be resawn or planed asymmetricallyon opposite faces for precision jobs or turnedor carved to produce intricate shapes anddesigns. It shall be deemed to be free fromobjectionable stresses if prongs prepared fromthe test samples according to the procedure inAnnex D have no appreciable curvature afterroom-drying for 24 h.12.5 Seasoned timber shall beinspected for defects( both natural and seasoning defects ) in accor-dance with specifications laid down for sawntimber or quality of timber for various end-uses.

13 STORAGE AND TRANSPORT OFSEASONED TIMBER13.1 As far as possible, seasoned timber shouldbe promptly used before its moisture contenthas had time to alter due to climatic changes.However, when storage becomes unavoidable,it should be stored in close stacks under a shedmaintained under dry conditions to retardmoisture content change. Stacks may be fur-ther protected by polythene covers enclosingeach stack from all sides and the top. Planksand scantlings may be stored after strappingwith metal bands in small lots. Where sea-soned timber is required to be maintainedwithin close tolerances of moisture contentpending use for regular, large scale productionwork, such as for aircraft construction, railwaycoach shutters, ritle, furniture, pattern making,etc, storage should be done in conditioningsheds maintained at proper equilibrium mois-ture content conditions.13.2 Seasoned timber should be transported inclose stacks in covered wagons or under tarpau-lin covers to protect it against rain. Seasonedhalf-wroughts of timber for special use shouldpreferably be packed in gunny bags fortransport.

ANNEX A( Foreword )

ANTI-SHRINK TREATMENT FOR WOODA-l DETAILS OF TREATMENT and may be roughly estimated by the followingformula:A-l.1 Timber for high class jobs requiring pre- 30cision of shape and size in use, such as for rifle 7 x I.125fore-ends, dies for automobile bodies and pattern C = x 10making may be given an anti-shrink treatment 1 1with polyethylene glyocol (PEG)-1 000, to which -- _ __ -sodium pentachlorophenoxide has been added s l-53for protection against insects and fungi, provid- whereed that the treated timber shall be used indoors C = concentration of solutionl grams ofor shall be painted over with polyurethane or PEG-l 000 per litre of solution ( in theother effectively water-resistant paint. formula fibre saturation moisture con-tent of wood expressed as percentageA-l.2 The treatment shall be given to wood

of the oven-dry weight is 30; meanwith moisture content not less than 30 percent specific gravity of bound water in wood( preferably green freshly sawn wood ) and pre- is 1.1; specific gravity of PEG-l 000 isferably after shaping it roughly to the final form 1.125; and specific gravity of wood sub-and size to minimize treatment time. Treat- stance determined by water displace-ment shall be given for an adequate period to ment method is I.53 ).allow the chemical to penetrate through and S = basic specific gravity of the wood species,through for effective dimensional stabilization. green volume-oven-dry weight basis.A-l.4 The treated timber shall be close-stackedA-l.3 The minimum concentration of water under a polythene sheet cover for a few dayssolution of PEG-l 000 needed for imparting near after treatmenl, to promote diffusion of thechemical into the cell walls. It shall then becomplete dimensional stabilization to timber air dried or kiin dried in t ze normal mannerdepends upon the specific gravity of the wood before manufacture.

16


22/33

IS 1141 : 1993ANNEX B

( Clauses 4.5, 8.3.2.5, 8.4.1 and 8.4.5 )CLASSIFICATION OF SOME OF THE IMPORTANT INDIAN TIMBERS BASED ON

THEIR SEASONING BEHAVIOUR AND REFRACTORlNESSSPECIES TRADENAME

1)Abies densaAbies spp. ( other than Abies densa )Acacia catechuAcacia chundraAcacia IeucophloeaAcacia niloticaAcacia t ort i l isAcer spp.Acrocarpus fraxinifoliusAdina cordifol ia ( Hal dina cordifol ia )Aesculus indicaAglaia spp.Ailanthus spp.Albizia chinensisAlbizia lebbeckAlbizia odoratissimaAlbizia proceraAlnus spp.Alstonia scholarirAl ngia excel saAmoora wal l ichi iAnogeissus acuminataAnogeissus latifoliaAnogeissum penduleAnthocephalus chinensisAphanamixis polystachyaArtocarpus chaplashaArtocarpus heterophyllusArtocarpus hirsutusArtocarpus lokoochaAv icennia ofi cinalisBauhinia spp.Betula spp.Bischofia javanicaBombax spp.Boswellia serrataBridelia spp.Broussonet ia papyri fera

(2)red firfirkhairlal-kbairhiwarbabulIsrael babulmaplemundanihalduhorse-chestnutaglaiamaharukh and gokulsiriskokkokala-sirissafed-sirisalderchatianjutiliamariyonaxle wood ( bakli )kardahikadampitrajchapalshkathalainiiakoochbaenkanchanbirchuriamsemul and didusalaikasipaper mulberry

REFRAC-TORINESS(3)CCAAABABBBBAcBBBBCCABAAACBBBBBABBAccBc

KILNSCHEDULE(4)-I---VIVIIVIIIVIVVII-IVIYIVIIVIV-VI1-IIYIIIIIIIVV-VVLIEI--


23/33

IS 1141 1993SPECIES

(1)Buchanania spp.B t r xu s semper,virensCaIophyIIum spp.Canarium spp. ( other than Canariumstrictum )Canarium strictumCanthium spp.Carapa moluccensisCareya arboreaCassia i stul aCassia roxburghiiCastanopis spp.Casurina equisetifoliaCedrus deodaraCeltis australisChloroxylon sw ietenioChukrasia velutinaCinnamomum spp.Cleistanthus collinusCr_vpotonmeria ponicaCullenia rosayroanaCupressus torulosaDalbergia lat i fo l iaDalbergia serkeaDalbergia sissooDaphniphyIIum kimalyenseDi l l enia SW.Diospyros spp.Dipterocarpus spp,Duabanga grandifloraDy soxylum binectariferumDysoxylum malabaricumEfaeocarpus tuberculatus-Emblica oflcinalisEndospermum spp.Erythrina spp.Eucalyptus globulusEucalyptus tereticornisEvodia spp.Exbucklandia populneaExcoecaria agallochaFicus spp.Fraxinus s pp.Gardenia spp,.

TRADE NAME(2)charoli

boxwoodpoonwhite dhup

REFRAC- KILNTORINESS SCHEDULE(3) (4)B or C IIB VB 1VC I

white dhup Cbalasu I3pussur I3kumbi Aamaltas Avakai Achestnut 8casuarina Adcodar Cceltis Bsatinwood Achickrassy I3cinnamon Bkarada Asuji Ckarani Ccypress Crosewood Bsaras Bsissoo Bverm-ratendu Bdillenia l3ebony and marbIewood Agurjan and hollong Blampati Cdevdam Bwhile cedar Brudrak camla Abakota cpangara Cblue gum AMysore gum AKambli Bpiple Cgeon Cfigs Cash Bgardenia B

--VIVIVII-IV-IIIIVVIIVV---IIIIVIIIVII-VIVI-IV11

-II IIVV

18


24/33

IS 1141 1993SPECIES(1)

Garuga pi nnataGluta iravancoricaGmelina arboreaGrevillea robustaGrew ia t i l i i fo l iaGyrocarpus jackquiniHevea braziliensisHeritiera spp.Holarrhena antidysentericaHoloptelea integrifol iaHopea spp. ( other than Hopea odorata )Hopea odorataHymendictyon excelsumJuglans spp.Kingiodendron pinnatumKnema attenuataKydia calycinaLagerstroemia hypoleucaLagerstroemia IanceolataLagerstroemia parvifloraLagerstroemia speciocaLannea coromandet icaLophoperalum w eighti anumM achil us spp.Madhuca spp .Mall otus phil ippensisM angifera indicaMani lkara spp.Mani l toa polyandraM eli a azedarachM eli a composit aM esua ferreaM ichel i a spp.M il iusa tomentosaMil l ingtonia hortensisMitragyna parvi fo l iaMorus spp.Olea glanduliferaOlea spp.Ougeini a oojeinensisPalaquium spy.Parishia insignisParroti opsis jacqemonti anaPicea smithiana

TRADENAME(2)gargua

glutagamarisilver oakdhamantanakurubber woodsundrikurchikanjuhopeathingankuthanwalnutpineyjathikaipulapyinmabenteaklendijaruljhinganbanatimachilusmahuarainimangobullet woodpingpersial lilacmalaber neemmesuachamphoomnimichambelikaimmulberry and bolavern-gairolivesandanpali and talired dhupparrotiaspruce

REFRAC-TORINESS(3)BABBBC?ABBAACBBCcBBA5B

CBandCABCAABBABBBBBABBBBBC

KILNSCHEDULE(4)III-IIIVIVIIVVIIIIIIIIVII-IIIVVIIIIIVIV-VIIIIIIII-IIIII

-IIIVIIIVJVYI-VIEVIVL

19


25/33

IS 1141 : 1993SPEUES(1)Phoebe spp.

Pinus kesiy aPinus roxburghiiPinus wall ichianaPlanchonelkl IongipetiolataPoeciioneuron indicumPolyal th ia spp.Populus spp .Prosopis jul if l oraProsopis specegeraProtium serratumPterocarpus dalbergioidesPterocarpus marsupiumPterocarpus santalinusPterocymbium tinctoriumPierospermum acerifoliumPterygota alataQuercus spp.Robinia pseudacaciaSageraea ellipticaSalix spp.Samadera indicaSan al um albumSapium bacca urnSchima waNichiiSchleichera oleosaSchrebera sw i et eni oi desShorea assamicaShorea robustaSonneratia apetataSoymi da febrifugaSpondias spp.Sterculia urensSterculia vil losaStereospermum spp.Sw int onia _f?ori bundaStrychnos nux-vomicaStrychnos potatorumSw iet eni a spp.Syzygium spp.Tamarindus indictTamaris aphyllaTectona granllisTerminaha arjuno

TRADE NAME(2)bonsum

khasi pinechirkailIambapattiballagidebdarupoplarmesquite woodjhandmurterigapadaukbijasalred sanderspapitahathipailanarikelIndian oakblack locustchooiwillowkarimgottasandalwoodselengchilaunikusummokhamakaisalkeorarohiniamrakararudalpadricivitkuchlachillamahoganyjamanimlifrashteakarjun

REFRAC-TORINESS(3)B

BCCC

.ABCAABBBACBCABABCBCBABBABACCCBBAaBABBBB

KILNSCHEDULE(4)III-IIIII-VIIVIIVI-IVVI-IVIVI-

-III--VIVII--VVI

20


26/33

IS 1141 1993SPECIES

1)Terminalia beIIir icaTerminal i a bialataTerminalia chebulaTerminal ia mani iTerminalia myriocarpaTerminalia panicuIataTerminalia procera

r Terminal ia alata1 ( Terminalia cremdata Syn.1Termi nali a alat a pro parte.< Termi nali a coriacea Syn.I Termi nali a alat a pro parte.1 Termi nali a alat a Syn.I Terminal ia alata pro parte )Tetrameles nudijloraThespesia popul neaToona ci l i ataTrew ia nudif i oraTsuga dumosaUl mus w alI i chianaVateria indicaVitex spp.Wright ia spp.Xyl ia xyl ocarpaXanthoxylum IimoneIIaZiziphus spp.

TRADE NAME REFRAC-TORINESS2) (3)bahera B

white chunglum Bmyrabolan Ablack chuglam Bhollock Bkindal Awhite bombwe Blaurel A

maina cbhendi Btoon Bgutel chemlock celm Cvellapine Cmilla Adudhi Cirul Amullilam Bber B

ANNEX CClauses 8.3.2.6 and 8.3.2.7 )

PREPARATION OF KILN SAMPLES AND THEIR LOCATION

KILNSCHEDULE

4)IVIV--IIIVIIVVI

I-VIIII-IIVIIIV-VVI

C-l PREPARATION OF KILN SAMPLESC-l.1 Full length planks or scantlings selectedas representative of the kiln charge shall be setaside as the charge is being stacked. A 750 mmsample shall be cut from a distance of at least450 mm from one end of each plank or scantlingor from its centre as illustrated in Fig. 9. Atthe same time as this sample is cross cut fromthe plank or scantling a full cross-section mea-suring I2 to 20 mm along the grain shall also becross cut from near both ends of the sample.The sample and the two sections so obtainedshall be suitably marked for later identificationof the set, for example as A, B and Crespectively.

21

C-l.2 Immediately after cutting, the respectiveweights of the sample and the two sections shallbe recorded. The sample shall be end-coatedand then placed in the kiln charge. The sectionsshall be oven-dried and their oven-dry weightsdetermined. The moisture contents of the sectionsshall be calculated from the following formula:

Moisture content, percent= Wet weight-Oven-dry weight x looOven-dry weight

The mean of the moisture contents of the twosections B and C shall be taken as the moisturecontent of sample A and shall be used forcalculating the oven-dry weight of the sample.


27/33

IS 1141 : 1993This calculated oven-dry weight together withthe periodic weighings during kiln drying of the in pockets in the right-hand side of the kilnsample A will give the current moisture content charge. They shall be evenly distributed overand progress of drying, by use of the formula. this face of the charge both as to length andheight. The remaining half of the samples shallC-l.3 One half of the kiln samples prepared in be placed identically on the left-hand side of theaccordance with C-l.1 and C-l.2 shall be placed charge.

KILN SAMPLE

CL450mm-+==750mm ---J(t_12 To 20mm12 TO 20mm

FIG. 9 METHOD OF CUTTING ORIGINAL MOISTURE CONTENT SECTIONSANDKILN SAMPLEFROMTIMBERTO BE KILN DRIED

ANNEX DCauses 8.3.2.10, 8.3.2.13 and 12.4 )

FINAL CHECK TESTS ON KILND-l CUTTING OF TEST SECTIONSD-l.1 Three complete test cross-sections, 12mm to 20 mm long in the direction of the grain,shall be cross-cut from a point at least I50 mmfrom the ends of each kiln sample included inthe kiln charge ( see Fig. 10 ).D-2 TEST FOR MOISTURE CONTENT INTHE WHOLE SECTIOND-2.1 One of the three test sections obtainedin accordance with D-l.1 shall be weighedimmediately after cutting on a balance, thesensitivity of which is not less than 10 mg. Thesection shall then be dried in a ventilated ( andpreferably thermostatically controlled ) oven attemperature of 100C to 105C until the weightis constant. It shall then be weighed immedia-tely after removal from the oven.D-2.2 The percentage moisture content in thewhole section shall be calculated as follows:

Moisture content(percent) =w.--.-I- wo x 1000

wherew, =W =

initial weights of test section, andoven-dry weight of test section.

22

SAMPLES IN A KILN CHARGED-3 TEST FOR MOJSTURE CONTENTDISTRIBUTION IN CROSS SECTIOND-3.1 The second test section out of the threecut in accordance with D-l.1 shall be markedon the freshly cut surface immediately aftercutting, so as to subdivide it into shell and corezones in case of timber 40 mm or below inthickness or shell, intermediate and corezones in case of thicker timber, in the mannerillustrated in Fig. Il. The section shall bequickly sawn to separate out the different zones.The two outside portions of the shell shall beweighed together, oven-dried and then weighedtogether again to calculate their moisturecontent in the manner of D-2 above. In likemanner, the two intermediately portions shallbe weighed together but the core shall beweighed as a single piece for determination oftheir respective moisture contents.D-3.2 Core moisture content determined accord-ing to the procedure D-3.1 in conjunction withthe moisture content in the whole sectiondetermined as per procedure of D-2 shall beused to judge conformity of the kiln seasonedcharge to the requireme;its of 8.3.2.13.


28/33

IS 1141 : 1993

D-4 TEST FOR RESIDUAL CASE HARDEN- below and six prongs in case of thicker asING STRESSES illustrated in Fig. 12. The middle prong in theformer case and prongs 2 and 5 in the latterD-4.1 The third test section out of the three shall be broken 0~1. The prong shall be roomcut in accordance with D-l.1 shall be marked dried for 24 h and its curvature shall then beand sawn so as to produce three prongs of recorded to judge conformity of the seasonedequal thickness in case of timber 40 mm or timber to the requirements of 8.3.2.13.

-I %d --12 TO 20mm

FIG. 10 TEST SECTIONSFOR FINAL CHECK

CORE

ILINTERMEOIATE

11 A WHOLETy;;STURE 11 B MOISTURE DlSTRlBUTlON 11 C MOISTURE DISTRIBUTIONSECTION FOR STOCK 40 MM SECTION FOR STOCK THICKEROR BELOW IN THICKNESS THAN 40 MM

FIG. 11 FINAL MOISTURE SECTIONS

23


29/33

B 1141 1993

STOCK LESS THAN 40 mmTHICK SHALL BE SAW.N ASSHOWN SO AS TO PRODUCETHREE PRONGS OF EQUALTHICKNESS FOR CASEHARDENING TEST. THECENTRE PRONG SHAM. BEBROKEN OUT

NO CASEHARDENING

r

STOCK THICKER TkAN 00 mm NO CASE

SEVERE CASEHARDENING

SEVERE CASESHALL BE SAWN AS SHOWN HARDENING HARDENINGTO PRODUCE SIX PRONGS OFEQUAL THICKNESS FOR CASEHARDENING TEST. PRONGSTWO AND FIVE SHALL BEBROKEN OUT

FIG. 12 CASE HARDENING SECTION : SECTION TO BE ROOM DRIED BEFORECONCLUSIONIS MADE AS TO CASE HARDENING

24


30/33

Is 1141 : 1993

Chairman RepresentingSHRl s. SHYAM SUNDER In Personal capacity ( 2989/D, I 2 Main Mal, TndStage, I ndranagar,Bangalore 560 038 )MembersSHRIANIL AGARWALSHRI H. C. PANT ( Alternate )SHRI B. K. BRALLASHRI G. N . BUL LAGANNAVARSHRI A. K . CHATTERJ EESHRI 0. P. SHARMA (Alternote )

Ministry of Defence, Directorate of Standardization, New DelhiWIMCO Ltd, New DelhiKarnataka State Forest Industries Corporation Ltd, BangaloreDirectorate General of Technical Development, New DelhiForest Department, Govt of Uttar Pradesh, Lucknow

ANNEX E( Foreword )

COMMITTEE COMPOSITIONTimber Sectional Committee, CED 9

CHIEF CONSERVATOROF FORESTS ADDL CHIE F CONSERVATOROF FORESTS( Alternate )CHIE F CONSERVATOROF FORESTSCONSERVATOROF FORESTS Alternote )CHIE F CONSERVATOROF FORESTS GENERAL )DIRECTOR ( TRACK )J T DIRECTOR, CE ( TM ) ( Alternate )DIRECTORDY DIRECTOR OF NAVAL ARCHITE CTUREASSTT DI RECTOR OF NAVAL ARCHITE CTURE( Alternare )DK P. M. GANAPATHVSHRI V. SIVANANDA Alternate )DR R. GNANAHARANSHRI N. H EMBRAMSHRI L. R. LAL I,A ( Alternate )INSPECTOR GENERAL OF FORESTSADDL INSPECTORGENERAL OFFORESTS Alternate )SHRI D. K . KANU NGOSHRI B. K . MANDAL ( Alternate )SHRI K. S. LAULYSHRI P. T. S. MENON ( Alternate jSHRI B. A. M ATHEWSSHR~M. M. MI STERSHRI A. G. DHONGADE ( Alternate )SHRI NARENDRA KUMARSHRI S. P. SINGH ( Alternate )DR A. N. NAYERSHRI R. C. PRASADSHRXB. M. PRASAI) I Alternate)PRESIDENTEXECUTIVEDIRECTOR ( Alternate )

SHRI S. S. RAJ PUT

DR V. RANGANATHANSHRI A. C. SEKHARSHRI S. N. SHARMASHRI K. S. SHUKL ALT COL G. B. SINGHSHRI J . L. BOTHRA ( Alternate )SHRI N. K. UPADHYAYSHRIN. M. WALECHASHRI ANAND PRAKASH ( Alternate )SHRI Y. R. TANEJ A,Director ( Civ Engg )

Himachal Pradesh Forest Department, SimlaForest Department, Govt of Karnataka, BangaloreMinistry of Railways, New DelhiForest Research I nstitute, Dehra DunNaval Headquarters, New Delhi

Indian Plywood Industries Research Training Institute,BangaloreKerala Forest Research Institute, PeechiEngineer-in-Chiefs Branch, Army Headquarters, New DelhiMinistry of Environment and Forests, New Delhi

National Test House, CalcuttaIndian Plywood Manufacturing Co Ltd, BombayForest Department, Andaman Nicobar Islands, Port BlairNational Buildings Organization, New DelhiCentral Building Research I nstitute, RoorkeeIn personal capacity ( C-59 I nderpuri, ?Vew Delhi 11001.2 )Bihar State Forest Development Corpn L td, PatnaFederation of Indian Plywood and Panel Industry, New DelhiConvener, Timber Terminology and Classification Subcommittee,CED 9 : 1, Timber Testing Subcommittee, CED 9 : 9, and TimberConversion and Grading Subcommittee, CED 9 : 10In personal capa city 28-C, N Block, Malviya Nagar Ext, Saket,New Delhi 110017In personal capacity ( 146 I_,NE Layout, Seethammadhara,Yisakhapatnam 530013 )Convener. Timber Seasoning and Treatment Sub-committeeCED9:3,Convener, CED 9 : 11Andaman Chamber of Commerce Industry, Port BlairDirectorate General of Supplies Disposals, New DelhiDirectorate General of Civil Aviation, New DelhiDirector General, BIS ( Ex-officio Member )$femb_er SecretarySHRI SANJAY YANTAssitant Director (Civ Engg ) , BIS

( Corzlinued on page 26 )25


31/33

IS 1141 I993Continued from page 25 )

Timber Seasoning and Treatment Subcommittee, CED 9 : 3Convener

SHRI S. N. SHARMAM embersDR S. P. WNGH DHAKAREY

SH~I J. K. SINHA ( Altern@ )DIRECTORDIRECTOR

DR S. ANANTHANARAYANAN Alternate )D~RECTOR TRACK)JT DIRECTOR TM ) Alternate )DISTRICTFORESTOFFICERDR R. GNANAHARANSHRIP. P. GUPTASHRI B. CHATTERJEE AIternate )SHRI K. S. LAULYSHRIP. T. S. MENON ( Alternate )SHRI M. M. MISTRYSHRI A. G. DHON~ADE ( Alternate )SHRIA. P. MISHRASHRI S. PANDEYSHRI J. P. BHARDWAJ ( mate )SHRI SANKRAKRISHNANSHRI M. V. D. MENON ( Alternate )DR SATISHKUMARDR INDRADEV Alternate )SHRI N. SETHURAMANDR RAVI MOHAN ( Alternate )DR Y. SINGH

Representi ngThe Gurdit Ixtitute Pvt Ltd, Dharwad

Controller+te qf Quality Assurance ( General Stores ), Ministryof Defence, KanpurInstitute of Wood Science & Technology, BangaloreTndian Ply)vood Industries Research & Training Institute,BjngaloreMinistry of Railways. New DelhiForest Department, Govt of Andhra Pradesh, Rajhamandry

Kerala Forest Research Institute, PeechiASCIJ India Limited, CalcuttaThe Indian Plywood Manufacturing Co Ltd, BombayNational Buildings OrgapiTatioq, New &lhiGujarat State Forest Development Corporation, VadodaraDirectorate of Standardization, Mjn@@y of D,efence, New DelhiKutty Flush Doors & Furniture Pvt Ltd. MadrasForest Products Division ( Wood PFeservation ) Forest ResearchInstitute, Dehra D_unSndToI Limited, BombayCentral Building Research Institute, Roorkee

26


32/33

Standard MarkThe useStandards Act, of the Standard Mark is,governed by the orovisions of the Eur cau of ind m1986 and the Rules and Regulations made thereunder. The Standard Markon products covered by an Indian Standard conveys the assurance that they have beenproduced to comply with the requirements of that standard under a well defined systemof inspection, testing and quality control which is devised and supervised by BIS andoperated by the producer. Standard marked products are also continuously cheked byBIS for conformity to that standard as a further safeguard. Details of conditions underwhich a licence for the use of the Standard Mark may be granted to manufacturers orproducers may be obtained from the Bureau of Indian Standards.


33/33

Buean of Indian StandardsBIS is a statutory institution established under the Bureau oj fndiun Standardr Act 1986 topromote harmonious development of the activities of standardization, marking and qualitycertification ofgoods and attending to connected matters in the country.CopyrightBIS has the copyright of all its publications. No part of these publications may be reproducedin any form without the prior permission in writing of BIS. This does not preclude the free use,in the course of implementing the standard, of necessary details, such as symbols and sizes, typeor grade designations.( Publications ), BIS Enquiries relating to copyright be addressed to the Director

Revision of Indian StandardsAmendments are issued to standards as the need arises on the basis of comments. Standardsare also reviewed periodically; a standard along with amendments is reaffirmed when such reviewindicates that no changes are needed; if the review indicates that changes are needed, it is takenup for revision. Users of Indian Standards should ascertain that they are in possession of thelatest amendments or edition by referring to the latest issue of BIS Handbook and StandardsMonthly Additions. Comments on this Indian Standard may be sent to BIS giving the followingreference:Dot : No. CED 9 ( 4790 )

Amendments Issued Since PublicationAmend No. Date of Issue Text Affected

Headquarters:BUREAU OF INDIAN STANDARDS

Manak Bhavan, 9 Bahadur Shah Zafar Marg, New Delhi 110002Telephones : 331 01 31, 331 13 75

Regional Offices :Central : Manak Bhavan, 9 Bahadur Shah Zafar Marg

NEW DELHI 110002Pastern : l/14 C. I. T. Scheme VII M, V. I. P. Road, ManiktolaCALCUTTA 700054

Northern : SC0 445-446, Sector 35-C, CHANDIGARH 160036

Southern : C. I. T. Campus, IV Cross Road, MADRAS 600113Western : Manakalaya, E9 MIDC, Marol, Andheri ( East )

BOMBAY 400093

Telegrama : Manaksanstha( Common to all Offices )

Telephone

{33101 31331 13 75

{37 84 99, 37 85 6137 86 26, 37 86 62

t-53 38 43, 53 16 40I 53 23 84

{235 02 16, 235 04 42235 15 19, 235 23 15632 92 95, 632 78 58632 78,91, 632 78 92

Branch : AHMADABAD. BANGALORE. BHOPAL. BHUBANESHWAR. COIMBATORE.FARIDABAD. GHAZIABAD, GUWAHATI. HYDERABAD. JAIPUR. KANPUR

is.1141.1993 seasoning of timber

Documents