GUIDELINES FOR CONSTRUCTION OF

MASONRY WITH SIPOREX BLOCKS

271246 Puppala Vamsee

271247 Helen Anitha R

271248 SRINAATH R

271249 Priya Rajeev

271250 Vikhyat Ramachandran

271251 Chinmai G Rao

271253 Nirman Rathi

271254 Riv Mahesh

SIPOREX UNREINFORCED BLOCKSAvailable in the following dimensions

Oven dry density-450 Kg/Cum

Thk X Height X Length

075 x 240 x 650 mm100 x 240 x 650 mm

Oven dry density-600 Kg/CumThk X Height X Length125 x 240 x 650 mm150 x 240 x 650 mm200 x 240 x 650 mm

GENERAL1. Details of sizes of blocks for walling, partitions & cladding are given in the price list.

2. Blocks should be stacked in dry, well ventilated areas on a level ground. Block should be placed on edges (in the direction of 240 mm height) not on flat (in the direction of the thickness). Different stacks should be maintained for different sizes of blocks.

3. Siporex blocks should not be used below ground level or in plinth.

4. Damp-proof course should be provided before starting superstructure masonry.

5. Generally, load bearing structures using 20 cm (8”) Siporex blocks can be constructed up to two storeys, i.e. G + 1 Buildings. Over G+2, will be a “Framed” structure. However, it is necessary to design load bearing / partition wall as per relevant IS specifications.

6. Siporex blocks and slabs are highly suitable for extension or addition of floors to existing old or new buildings because of their lightweight characteristics

MASONRY WITH SIPOREX BLOCKS

1. Cement mortar 1 : 6 using Portland cement should be used.

2. Blocks shall be placed in the direction of 240 mm height in the masonry.

3. It is not necessary to soak the Siporex blocks before their use in masonry. Theirsurface should be wetted sparingly and afterwards water should be sprinkled forcuring of masonry joints.

4. For breaking of joints in the masonry, specifications for brick masonry work shallbe adopted for guidance.

5. At door and window openings, 2 nos. 6 mm dia bars should be provided at the topof the openings to avoid cracks on plaster. The bars should be provided in thecourse immediately above the lintel and bar should be extended 0.6 m on bothsides.

6. Inter-locking should not be done at junctions of load bearing and non-load bearingpartition walls. Connections between these walls can be achieved by:

a) Nailing galvanized strips across every third joint with 12 mm galvanized oraluminum nails, or

b) By providing 6 mm dia bars 200 mm long at the Junction.

Siporex blocks are wetted before being

laid in construction of walls.

Top: A wall built using siporex blocks

Bottom: Stacking blocks, on site

MASONRY WITH SIPOREX BLOCKS

7. Inter-locking at junction of 2 load bearing walls should be done as in brick masonry.At the junction between conventional and Siporex block masonry, chicken meshshould be provided in the plaster to avoid cracking at the corners and junctions.

8. Bond beams, 200 x 100 mm (8" x 4") should be provided throughout the load bearingwalls below the Siporex slabs for floors and roofs, e.g. if there are three rooms withcontinuous wall, bond beam should be continuous with 12 mm dia bars. 2 Nos. and 6mm dia bar stirrups of 175 mm (7") centre to centre shall be provided asreinforcement.

9. For Unsupported Siporex: Walling height ≤ height 18 times the thk of wall and ……………………… horizontally ≤ 24 times thk of wall for load bearing walls. For partition or non load bearing walls unsupported length and height should be:≤ 30 times the thickness of walls.

In cases where the length of wall exceeds these limits, Siporex pillars can beconstructed. If height exceeds the prescribed limit, bond beams at a suitable heightin the wall should be provided (IS-6041 and IS 1905) .

10. The work of concealed plumbing & concealed electrical wiring fittings, etc., shouldbe decided in advance. Work of chasing should be done in Siporex blocks withproper tools to avoid damage to blocks & to prevent cracks in plaster.

INTERNAL AND EXTERNAL PLASTER

a) Siporex walls should generally be plastered on both sides in two coats.Internal walls in industrial buildings may be left unplastered if so desiredand joints should be properly finished.

b) Block walls should be wetted sparingly before plaster.

c) Method of plaster is similar to that of plaster on brick1 concrete walls.

d) Internal plaster should be carried out in 2 coats with cement mortar 1 : 3(One part of Portland cement and 3 parts of screened and washed sand).First coat may be of 4 to 6 mm thick and the second coat (finishing coat)

e) External plaster should be carried out in 2 coats with cement mortar 1 : 3(One part of Portland . cement and 3 parts of screened and washed sand.)First coat may be of 8 to 10 mm thickness and the second coat (finishingcoat) may be about 10 mm thick.

f)Plastered surfaces should be watered for at least one week.

PAINTING

a) INTERNAL PAINTING

• For plastered walls the method employed is the same as for other plastered walls.

• For unplastered walls in industrial buildings, berating paints such as acrylicemulsion can be applied. They provide a more impermeable surface and are oftenwashable.

b) EXTERNAL PAINTING

• For exterior painting of plastered walls, where whitewash is the most commonmethod. Longer life and better weather protection is obtained with a cementpaint. Better moisture protection is obtained with all cement paints by applicationwith a stiff brush raher than by spraying

FIXTURES IN SIPOREXa) DOOR AND WINDOW FRAMES:

Door and window frames are attached in the surrounding masonry with 7" aluminum orgalvanized iron cut nails hammered directly into the Siporex blocks. The nails should be spacedat a maximum 40 cm and the first nail should not be farther than 20 cm from a corner. 14gauge screws may be used. They should penetrate at least 50 mm into the Siporex blocks andshould preferable be driven into raw plugs. ALL NAILS AND SCREWS SHALL BE INSERTED INTOTHE BLOCKS AND NOT ALONG JOINTS.

b) WASH BASINS:

Pedestal type wash basins are fixed to the wall using 3" x 14 gauge screws in raw1 plugs. Wherewash basins are mounted on brackets, use of 4" x 14 gauge screws in raw1 plugs will givesufficient strength and rigidity.

c) CUPBOARDS:

For most purposes, 3" x 14 gauge screws in raw1 plugs should prove satisfactory. For heavilyloaded cupboards, timber connector should be used between cupboards and Siporex walls, inaddition to screws in raw1 plugs.

FIXTURES IN SIPOREX

d) ELECTRICAL FITTINGS:-Light fuse boxes and switch boxes should be fixed using 3" x 10 gauge screws in raw1 plugs. -Heavier fittings should preferably be mounted on the floor or fixed with through bolts. -Wall brackets, light switches, should be fixed using 8 to 10 gauge screws, not less than 3" long in raw1 plugs. -Where conduit runs are made on surface the supporting saddles may be fixed with 2" x 10 gauge screws directly into Siporex or where the conduit is likely to be subjected to loads during erection, by 811 0 gauge screws in raw1 plugs.

e) HANDRAILS:Wherever possible these should be through-bolts. Failing this, use 4" x 14

gauge screws in raw plugs.

f) HOT AND COLD WATER PIPES:The supporting brackets or holderbats should be fixed to walls using 2"x 10

gauge screws in raw1 plugs.

PRECAUTIONS

AGAINST CRACKING IN BLOCKWORK

1. Limit the cracking to the joints, so that it can be repaired easily. Hence, mortarsweaker than the blocks are always recommended.

2. Where uneven settlement of foundations is feared, proper bonding and the use ofreinforcement in horizontal joints will tend to reduce risks of cracking bydistributing stresses throughout the wall.

3. In block walls abutting against columns and beams of load bearing frame,differential movements can be caused by settlement, variable loading conditionsand changes in temperature and humidity.

4. For blockwork partitions, care should be taken to limit deflection of floors orpartitions should be strengthened by use of bond beams or reinforcement in thelower courses.

5. Use resilient material stoppers between door shutter and wall at one or two pointsor use door closer to avoid cracking in walls by impact of slamming of doors, etc.,particularly in these rigid partitions.

6. Alleviate temperature & shrinkage stresses in the wall by incorporating controljoints at appropriate intervals and locations.