euroclad guide to design and installation of trapezoidal systems

7/27/2019 Euroclad Guide to Design and Installation of Trapezoidal Systems

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August 2007

Design and installationrecommendations


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DESIGN AND INSTALLATION RECOMMENDATIONS 1

Specification and installation

Roofs 5Lightning protection 7Flashings information 7Wall cladding 8Curved profiles 9Liner sheets 10Fragility 11

Summary of non-fragility status 12Cut edge protection 16Cantilever 16Penetrations 16Weights and calculations (table) 17Handling and storage 19Guidance on breather membranes 19

Inspection and maintenance

Wind loads 21Cleaning of pre-finished steel 21

Washing 21 Annual inspection (table) 22Removing mould 22

Touch-up painting 23Suppliers of complementary products 23

Acoustic performance

Research 25What is noise? 25Measurement 25Double skin constructions 26Mineral fibre density and system comparison (graph) 27Perforation 28Single and double skin system comparison (graph) 29

Trapezoidal acoustic performance (graph) 30

The building regulations

Calculation of U-values 31 Thermal bridging 31 Air permeability 32

Corus Colorcoat

Products and services 37

References

Relevant publications 39

Contents


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In the following pages we have attempted to

outline some of the basic parameters for fixing

Euroclad trapezoidal profiles successfully.

For the most part, the advice given will be

sufficient, however, there will always be a

number of unusual requirements or problems

which arise and in those instances it would be

wise to contact Euroclad for particular advice.

In the same respect, when a method for fixing

is listed below, it is not necessarily the only

method of achieving a successful result.

To list every possible permutation and

combination would be impossible.

Introduction

The ones listed are those that have been

found to be successful, others do exist.

Please read the sections relevant to your

particular needs carefully and if any questions

arise do not hesitate to contact Euroclad

where further clarification can be given.


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Roofs

Euroclads profiles are used extensively in the roofing of both new and refurbished buildings. Those identified inthe sections on roofing profiles are ideally suited to thisapplication, however, certain criteria must be adhered toif the profile is to achieve its full potential.

The use of trapezoidal weather sheets should be avoidedwhere the pitch is below 4. For pitches below this,Euroclad Euroseam or Secret fix should be considered.Please refer to product specific literature in theseinstances. The following summary refers to trapezoidalprofiles only.

Specification and installation

Table 1. Size, shape and position of sealant(s) for typical 150mm End lap and Side lap details

Profiles: 914/38mm, MW5R and 1000/32mm

*Where a seal is required at the bottom of the lap to keep out dirt and trapped water a bead of premium quality neutral cure silicone sealant positionedapproximately 15mm from the bottom of the lap is suggested. The silicone sealant should ideally conform to classification ISO 11600 - F - 25 LM of BS EN ISO 11600 : 2003 and adhesion to the substrates involved verified.

Figure 1. Typical end lap detail

See MCRMA Technical Paper 16, for further details.

Built-upsystems

Profiledmetal tometalcombinations

Roof pitch Side lap End lap

Less than 5 Not recommended Not recommended

5 to 10 Fixings at not greater than 450mm centres Two lines of sealant (central or asymmetric primary fixing position)The lap should also be sealed with a A single run of 6 x 5mm or 6mm bead sealant positioned 15mm from eachcontinuous bead of mastic end of the lap

Above 75 As above The sealing of the end laps may be omitted unless severe conditions are anticipated

10 to 15 Fixings as above, but the sealant may be As aboveomitted (dependent on local conditions)

Profiledmetal toGRProoflightcombinations

Less than 5 Not recommended Not recommended

5 to 10 Fixings at not greater than 450mm centres Two lines of sealant (central or asymmetric primary fixing position)The lap should also be sealed with a A single run of 6 x 5mm or 6mm bead sealant positioned approximatelycontinuous bead of mastic 10 15mm either side of the primary fixing*

Or alternatively:Three lines of sealant (central primary fixing position)A single run of 6 x 5mm, 6 x 8mm bead sealant positioned 15mm from eachend of the lap with an 18 x 4 or 22 x 5mm U-section positioned beneath theline of the primary fixing

Above 75 As above The sealing of the end laps may be omitted unless severe conditions are anticipated

10 to 15 Fixings as above, but the sealant may be As aboveomitted (dependent on local conditions)


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DESIGN AND INSTALLATION RECOMMENDATIONS6

1. Pitch

The pitch of the roof should be chosen to guaranteegood drainage, taking into consideration the localconditions (i.e. maximum wind load and snow loadings).Whenever possible the pitch should exceed 15.When a pitch of less than 15 is specified the following

fixing is recommended.

2. Primary fixing

It is recommended that the profiles should be fixedwith self-sealing, self-tapping screws from a reputablemanufacturer. They can be positioned in the trough orcrest of a profile, at a frequency of every trough or crestfor end laps and every other trough or crest atintermediate purlins.

3. Secondary fixing

It is recommended that all roof profiles are side stitchedwith the appropriate fixings at centres not greater than450mm unless particularly severe conditions areanticipated.

4. Gauge

Euroclad recommend the use of at least 0.7mm gaugein all roof situations. It will often be the case thatreference to the load tables will reveal that 0.5mmmaterial will satisfy the design load. However, where agauge less than 0.7mm is specified, provision should bemade to avoid damage during erection and subsequent

roof traffic when point loadings may become morecritical.

5. Direction of lay

Particular reference should be made to the underlapand overlap configuration of the particular profilespecified. The sheets should then be laid as Figure 2.

The side laps should, where possible, be laid awayfrom the direction of the prevailing wind.

6. Drilling and cutting

All holes must be drilled and not punched. It isimperative that the residue swarf be immediately sweptoff the sheet to avoid unsightly staining.

All cutting of profiled sheet on site should be achievedwith a nibbler tool or cladding saw. These tools aredesigned to impart the minimum of heat to the sheet.

The sheet should not be cut with a carborundum discor portable circular saw.

Any slight surface damage which may have occurredduring fixing should be made good with either touch-uppaint or PVC paste which is supplied to match allpre-finished steel colours.

7. Translucent sheet

Available in GRP to suit all Euroclad profiles . These canbe supplied as single sheets, double skinned, or tripleskinned. The double or triple skin can be achieved asa factory sealed unit, or when Euroclad liner is specified,as two or three independent sheets which can beconstructed on site to achieve a satisfactory rooflight.It is essential to effectively seal against moisture, orcondensation problems may arise. Each rooflightmanufacturer has their own technical departments.Please refer to MCRMA Technical Paper 1 forfurther details.

Figure 2. Direction of lay


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SPECIFICATION AND INSTALLATION 7

Lightning protection

Lightning is formed as a result of a natural build-up of electrical charges within storm clouds that discharge toearth. The magnitude of the electric current can rangefrom around 3,000 and 200,000 amps with potentials of 100 million volts. The calculated probability of structurallydamaging lightning strikes is once in every 500 years.

In general, a building with metal roof and wall claddingwill provide the best overall protection against lightning,especially when taking account internal electronicequipment, which may be affected by the electro-magneticeffects of lightning.

The main components of a lightningprotection system comprises of:

Air terminat ions

Down conductors

Earth terminations.

Air terminations

It is the air termination networks that have the greatestinterface with the roofing and consist of conductors ona 10 x 20m grid. Metal roof cladding provides a good airtermination network.

Down conductors

The air termination network must be securely fastenedto the down conductors which should be at 20m centresaround the perimeter of the building. Structural steelwork or a reinforced concrete structure can be used as thedown conductors.

Earth terminations

These are connections between the down conductorsand an earthing electrode driven into the ground.

A detailed explanation of the above is given inBS6651 : 1999 Code of Practice for Protection of Structures against Lightning, the notes are intendedto be for guidance only and it is recommended that alightning systems engineer be consulted.

Flashings information

Euroclad manufacture flashings using some of the mostup to date equipment in Europe. The flexibility of themanufacturing process allows the widest choice to thespecifier.

The computer controlled power presses and foldersallow Euroclad to produce details with an accuracy and

consistency which has been hitherto unachievable. These presses and the use of the best available materialsguarantees the quality of the product to the customer.

All flashings, unless otherwise specified, wil l be suppliedin 0.7mm gauge for steel and 0.9mm for aluminum.

These are avai lable in colours and finishes which canmatch or contrast with the cladding dependent uponspecification.

The standard length is 3.658m (12 feet) with the extralength helping the client maintain a good line andminimising joints. The joints can be either lapped or butt

jointed and, where required, the butt joints are 150mmin length.

Where curved sheeting is specified, curved flashings canbe manufactured to suit.

The drawings are indicative of good practice for each of the details, but other methods may be equally effective.However the details are arranged, it is important toincorporate the following flashings requirementswhenever possible.

1 450mm spacing (or every other corrugation)between primary fixings.

2 For open shaped flashings, a minimum 150mmlap on roofs and minimum 100mm lap on wallsis required.

3 For closed shaped flashings, butt straps shouldbe used.

4 Butt straps should fit within the flashing, with anallowance for sealant thickness.

5 Never leave edges of flashings un-stiffened.Either return a short edge or fold it back flat onitself (welt).

6 Sealants should be placed as near to cut edgesas possible.

7 Avoid any detail that can trap or dam water.


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DESIGN AND INSTALLATION RECOMMENDATIONS8

8 Arrange overlaps away from the prevailing wind.

9 Paint cut edges when there is a risk of watercollecting on them.

10 Avoid large flat areas in the design (200mm 250mm).If necessary, incorporate a shadow line within thelarger flat face.

11 Use factory pre-fabricated corners, rather thanon-site cutting and bending.

12 Care should be taken in the design and installationto ensure air permeability is minimised, using profiledfillers where necessary.

Further information can be found in the MCRMA Technical Paper No. 11: Flashings for Metal Roof andWall Cladding. This publication includes extensiveand comprehensive guidance for the design, installationand maintenance of flashings employed in the modernbuilding envelope.

Wall cladding

Ideally suited to the cladding of the walls of developmentsincluding retail, educational, health service, commercialand industrial. All the trapezoidal profiles in the productrange are suitable for use in vertical applications.

Aesthet ics are undoubtedly the main criteria upon whichvertical cladding is chosen. The cladding may be fixedvertically, horizontally or even diagonally but thespecification of reverse profile as depicted in the

cladding section of the brochure imparts certainadvantages to the aesthetics irrespective of the mannerin which the sheets are laid.

Advantages of the reverse profile

a Reduces the shade effect, and with its narrowertrough and wide crest the colour of the sheet ishighlighted rather than the shadow.

This effect is even more not iceable when claddingis laid horizontally.

b Effectively hides the fixings which are fixed inthe trough.

c If horizontal cladding is used a very effective profiledcorner piece can be incorporated successfully.

Horizontally laid wall cladding

Without doubt this is one of the most difficult applicationsfor profiled sheet. Aesthetics are obviously paramount andgreat care is needed to guarantee a successful result.One of the most common problems is the uneven effectresulting from careless fixings. The precise alignment of

end laps is critical.

However, with certain precautions observed the resultcan be very effective and several features can beincorporated to give a building a particularly pleasingappearance. One of the options open to horizontalcladding is to incorporate profiled mitred corners orcurved profiled corners (either crimped or smooth).

Several key points need to be observed to ensure asuccessful result:

a Sheets are laid from the bottom up i.e. the firstsheet laid is the one adjacent to the drip detail.

b Cover width must be checked on each sheet as fixed.

c Alignment of end laps requires time and care.

d Sheets should be fixed in every trough.

e The inclusion of a feature band in the claddingmust be approached with care, as any stretchingor shrinking of the cover width by the fixer toaccommodate such a feature will have an adverseaffect upon the aesthetics of the elevation.

f Steelwork must be checked carefully since

inaccuracies will be telegraphed through thecladding sheet.

g Do not use forward PVDF for horizontal cladding.

h Always use 0.7mm gauge for horizontal sheets.


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Vertically laid wall cladding

The standard method of fixing wall cladding with theprofiles running from eave to drip details. Although theprofiled sheet lends itself to this application, care mustbe taken to ensure a successful result:

a Irrespective of profile, side laps, where possible,should be laid with the overlap away from theprevailing wind.

b End laps should be a minimum of 100mm.

c Irrespective of profile, the stitching of side lapsis at the discretion of the cladding contractor.Where deemed necessary side laps should be fixedat 600mm centres.

d The primary fixing of the profile is generallyaccomplished in the trough using self-tapping,self drilling fixings, from a reputable manufacturer.

e Under normal UK urban conditions, fixing should beused in every trough for end laps and every othertrough at intermediate purlins.

f All holes should be drilled, not punched.

g 0.5mm gauge material is usually specified.

SPECIFICATION AND INSTALLATION 9

Curved profiles

When fixing curved profiles, certain basic rules should befollowed to ensure a high quality appearance is achieved:

a Throughout the project the need for care isparamount since the curved profiles are extremelyrigid and cannot be adjusted during fixing, as ispossible with non-curved sheets.

b A complete tier of sheets must be completed beforemoving on to the next tier.

c When ordering, remember that most of Eurocladprofiles are handed and therefore direction of layshould be indicated so that the sheets can besupplied with the correct underlap/overlapconfiguration.

d Where mitred corners are designed they shouldbe fitted first, and cladding laid away from them(Figure 3). This then involves a slip flashing wherethe sheets meet (Figure 4).

e Curved profiles may be specified in either 0.5mm,0.7mm or 0.9mm gauge Corus Colorcoat

pre-finished steel.

Figure 3. Mitred corners and claddinglay-out direction

Figure 4. Three alternative methods ofincorporating a slip flashing


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DESIGN AND INSTALLATION RECOMMENDATIONS1 0

Liner sheets

1 Euroclad liner sheets are usually specified withEuroclad outer sheet and hence are designed witha common cover width to minimise problems whenfixing. They can, however, be used successfully inconjunction with a variety of systems.

2 In the over-rail system the liner sheet is laid first.

Four primary fixings per panel are recommendedwhich have the function of temporarily securing thesheets and helping to maintain cover width andposition before the spacer system is fully secure.

3 The insulation quilt is laid from ridge to eave allowinggenerous side and end laps to prevent gaps. The railand bracket system is used to trap the insulation andthen is secured by the recommended fixings to thecladding rail. The use of the rail and bracket systemin this manner overcomes the problems of theintegrity of the system relying upon the compressionof the insulation quilt and minimises the thermal

bridge effect.

4 If the liner sheet is being employed as a vapourcontrol layer, the side and end laps must be sealedand fixings with an integral sealed washer must beused.

5 The weather sheet is fixed to the spacer system withthe appropriate fixings.

6 Because of the flexibility of the sheet, care should betaken not to spread the cover width of the liner sheetwhen the fixings are installed.

7 The maximum spans for the 19/20mm linersheets are:

0.4mm 2.0m

0.5mm 2.1m

0.7mm 2.2m.

8 Liner sheets should be laid in tiers with the insulationand outer sheet.

9 Liner sheets are to be treated as fragile, untilcorrectly installed.

10 If large areas of liner sheets only are fixed lining out,damage may be caused because of the temporarynature of the primary fixing and the danger of trafficimposing loads that the panel is not designed tosupport.

11 Translucent sheets in either GRP or polycarbonate

are available to suit Euroclad liner sheets.12 With the new focus on air-tightness, the effective

sealing of the liner in both built-up and compositeconstructions is fundamental to the systemperformance.

Both in controlled small-scale tests and practical airpermeability tests in actual buildings, a correctlysealed metal liner successfully passes BuildingRegulations criteria.

The specification for sealing Euroclad liner sheetsis as follows:

a Side lap sealing 50mm x 1mm butyl sealingstrip (polybond or similar).

b End lap sealing 4mm butyl mastic bead,or a 6mm x 2mm, or a9mm x 3mm rectangularsection is recommended,fixed in each corrugation.

Position the sealant in straight, unbrokenlines covering the sheet laps.

Place into corrugations or troughs.

Do not stretch the sealant.

Ensure continuity and effectiveness of seal,especially at corners of sheets and at allpenetrations of pipes, ducts, rooflights etc.


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SPECIFICATION AND INSTALLATION 1 1

Fragility of Euroclad profiled sheets

In summary ACR(CP)001 : 2003 Recommended Practicefor Work on Profiled Sheeted Roofs states:

That a non-fragi le assembly should be specified .

That a competent company is chosen to carry outroof work.

That the classification of the roof assembly can beconfirmed by the supplier and that test data can beprovided to support the classification.

That drawings are available which can be used toset out the sequence of operations to fit sheets toa non-fragile classification.

That the condit ions affecting guarantees of non-fragility should be clearly stated

That special consideration should be given toClass C constructions

That specific information relat ing to maintenance of the products and which is relevant to non-fragility isprovided for inclusion in the Health and Safety file.

That materials handling should be reduced whereverpossible i.e. by ordering sheets to be packed insequence as they will be used or by splitting packson the ground before positioning on the roof.

In addition the HSE Question and Answer brief forthe Construction Industry on the Work at HeightRegulations 2005 states that Collective controlmeasures should always take priority over personalcontrol measures.

All of the above are provided for by Euroclad Elite Systems.

During the construction phase

The ability to use the fixed l iner as a working platformduring installation of the outer sheet can also speed theconstruction process and allow work under the lined outroof to progress. Sheets or rooflights which have notbeen fixed to achieve a non-fragile classification must betreated as fragile.

Euroclad profiles can be fixed to be non-fragile during the

construction phase.

The ACR(M)001 : 2005 test for non-fragility is a basictest to establish whether a roof assembly is fragile ornon-fragile. It does not necessarily mean that walking onthe roof will not damage the roofing product. Walkableis not recognised as a defined term by HSE and itshould not be confused with non-fragile.

However, in practice standard >30mm deep 0.7mm steelliner and deck profiles allow workers to walk on thesheets with less risk of causing foot traffic damage thanshallower profiles or thinner gauges. 19/1000 profile in0.7mm for example, although it can be fixed to achieveClass B, is still more prone to damage by foot traffic thanprofiles deeper than 30mm.

More care is required when a 0.4mm liner or 0.7mm steelperforated liner is used. Additional fixing requirementsalso apply to achieve Class C, such as the use of crawlboards and additional sheet end lap length. 0.4mm steelliner and 0.7mm perforated liners are more prone to

damage by foot traffic.

Fixing requirements for Euroclad profiles to achievenon-fragile classification are given in a number of Euroclad drawings. These are available to downloadfrom the Euroclad website: www.euroclad.com.

After construction phase

Sections 65-69 of ACR(CP)001 : 2003 give guidance onmaintenance requirements and minimum non-fragileclassifications.

Class C non-fragile assembly is acceptable for lowmaintenance roofs.

Class B non-fragile assembly is required for bothmedium and high maintenance roofs.

All Euroclad external roof sheets and 0.7mm liners(excluding perforated liners) can be fixed to achieveClass B.


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Classification:

Fragile: If the bag passes through an assemblyit is classified as fragile.

Class C non-fragile: if the assembly retains thesandbag after one drop it is classified Class Cnon-fragile.

Class B non-fragile: if the assembly retains the bagafter a second round of impacts the assembly isclassified Class B non-fragile.

Class A non-fragile: on inspection of the assemblyafter the second round of impacts by a competentperson. If the assembly shows no signs of damagethat will affect the long term strength or weatherabilityof the assembly, then the assembly may be classifiedClass A, non-fragile.

The following recommendations, which have been

generated from the test programme, have taken intoaccount known variables and allow for a very gooddegree of confidence. For instance, wherever resultswere felt to be marginal or may be affected by poor sitepractice tests were repeated, if necessary, until a gooddegree of confidence was present. No items which mayhave assisted the performance of the systems and aresubject to site conditions were used in the testprogramme ie no sealants or spacer brackets assistingthe liner profile performance.

Consult the Euroclad Technical Department if anyassistance is required or the application is unusual.

Incorrect installation, total failure of associatedcomponents, abuse and exceptional circumstances couldall still jeopardise non-fragility within the 25 year period.Long term non-fragility can therefore not be guaranteed.

Summary of non-fragility status

All elements should be regarded as fragile until fixed tothe specified standards

0.4mm steel liner profiles19/1000 liner 0.4mm steel

19/1000 0.4mm thick steel liner profile, fixed as shownin Euroclad Ltd Drawing FR4, can be classified Cnon-fragile on any span up to and including 1.8m, forboth in plane and curved roofs, and for spans up to1.8m on hips with any angle.

Also see ACR (CP)001 : 2003 Recommended Practicefor Work on Profiled Sheeted Roofs Annex B, whichgives recommendations re the use of crawl boards andgives a great deal of guidance re: the usage of Class C

Assemblies and the potential risks which need to bemanaged and considered.

The document recognises the potential risk from elementswhich may be engineered to pass Class C being closeto the boundary between fragile and non-fragile.Euroclad did not engineer the system to pass, allowed agood margin for site error and normal site practice andthis was confirmed by an independent consultant.

The same profile used in 0.7mm gauge can be fit tedto achieve Class B using normal methods see below.However, we still recommend >30mm deep profiles inthe majority of cases as these are more resistant to foottraffic damage.

20/914 and 20/1066 liner 0.4mm steel

20/914 and 20/1066 0.4mm steel liner profiles, fixed asshown in Euroclad Ltd Drawing FR6, can be classifiedC non-fragile on any span up to and including 1.8m,for both in plane and naturally curved roofs, and for spansup to 1.8m on hips with any angle.

0.7mm steel liner profiles19/1000 liner 0.7mm steel

19/1000 0.7mm thick steel liner profile, fixed as shownin Euroclad Ltd Drawing FR2, can be classified Cnon-fragile on any span up to and including 1.8m, forboth in plane and naturally curved roofs, and for spans

up to 1.8m on hips with any angle.


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MW5 Liner 0.7mm steel

MW5 0.7mm thick steel liner profile, fixed as shownin Euroclad Ltd Drawing FR3, can be classified Bnon-fragile on any span up to and including 2.1m, forboth in plane and curved roofs, and for spans up to1.8m on hips with any angle.

MW5 liner 0.7mm steel fully or pan perforated

MW5 0.7mm thick steel liner profile, fully or panperforated, fixed as shown in Euroclad Ltd Drawing FR7,can be classified C non-fragile on any span up to andincluding 2.1m, for both in plane and curved roofs, andfor spans up to 1.8m on hips with any angle.

Also see ACR (CP)001 : 2003 Recommended Practice forWork on Profiled Sheeted Roofs Annex B, which givesrecommendations re the use of crawl boards and givesa great deal of guidance re the usage of Class C

Assemblies and the potential risks which need to bemanaged and considered. The document recognises thepotential risk from elements which may be engineered topass Class C being close to the boundary betweenfragile and non-fragile. Euroclad did not engineer thesystem to pass, allowed a good margin for site error andnormal site practice and this was confirmed by anindependent consultant.

32/1000 liner 0.7mm steel

32/1000 0.7mm steel liner profile, fixed as shown inEuroclad Ltd Drawing FR1, can be classified B

non-fragile on any span up to and including 2.1m, forboth in plane and naturally curved roofs, and for spansup to 1.8m on hips with any angle.

20/1066 & 20/914 liner 0.7mm steel

20/1066 and 20/914 0.7mm steel liner profiles, fixed asshown in Euroclad Ltd Drawing FR5 can be classified Bnon-fragile on any span up to and including 2.1m, forboth in plane and naturally curved roofs, and for spansup to 1.8m on hips with any angle.

MW5 deck 0.7mm steel

MW5 0.7mm thick steel deck profile, fixed as shownin Euroclad Ltd Drawing FR10, can be classified Bnon-fragile on any span up to and including 2.1m, forboth in plane and naturally curved roofs, and for spansup to 1.8m on hips with any angle.

38/914 deck 0.7mm steel

MW5 0.7mm thick steel deck profile, fixed as shownin Euroclad Ltd Drawing FR9 can be classified Bnon-fragile on any span up to and including 2.1m, forboth in plane and naturally curved roofs, and for spansup to 1.8m on hips with any angle.

MW5 roof profile 0.7mm steel

MW5 0.7mm thick steel roof profile, fixed as shownin Euroclad Ltd Drawing FR14, can be classified Bnon-fragile on any span up to and including 2.1m, forboth in plane and curved roofs, and for spans up to1.8m on hips with any angle.

32/1000 roof profile 0.7mm steel

32/1000 0.7mm thick steel roof profile, fixed as shownin Euroclad Ltd Drawing FR15, can be classified Bnon-fragile on any span up to and including 2.1m, forboth in plane and curved roofs, and for spans up to1.8m on hips with any angle.

38/914 roof profile 0.7mm steel

38/914 0.7mm thick steel roof profile, fixed as shownin Euroclad Ltd Drawing FR8, can be classified Bnon-fragile on any span up to and including 2.1m,for both in plane and curved roofs, and for spans up to1.8m on hips with any angle.

Euroseam roof profile 0.9mm aluminium

Euroseam 0.9mm thick aluminium profile, fixed as shownin Euroclad Ltd Drawing FR16 can be classified Bnon-fragile on any span up to and including 2.1m, forboth in-plane and curved roofs and for spans up to1.8m on hips with any angle.

SF500 profile 0.7mm steel

SF500 0.7mm steel profile, fixed as shown in EurocladLtd Drawing FR17 can be classified B non-fragile onany span up to and including 2.1m, for both in-plane andcurved roofs and for spans up to 1.8m on hips with anyangle.

Trapezoidal profiles in aluminium

These should be considered fragile until further notice.


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Rooflights

The National Association of Rooflight Manufacturersguidance note 2006/1, clearly sets out the requirementsfor rooflights where profiled metal or fibre cement roofshave been separately demonstrated to be non-fragilewithout rooflights and is based on a large number of tests carried out by rooflight manufacturers.

Rooflights should never be walked on even if fixed to anon-fragile standard.

Appendix

ACR(CP)002 : 2005 gives guidance on Safe Working onFragile Roofs.

Test method

The test method used was the ACR(M)001 : 2005 Testfor Non-Fragility of Profiled Sheeted Roofing Assemblies,which is recognised by HSE as an acceptable way of determining the non-fragility of a roof construction.

The test involves dropping a 45kg sand bag from a heightof 1.2m, onto the roof cladding assembly, which has tobe supported by a standard test frame. Provided the bagdoes not fall through the construction, the claddingassembly can be classed as non-fragile. To warrant thisclassification, the roof must be able to withstand the testin any location.

Tests were carried out by Mr Peter Roberts , anindependent consultant and Mr Paul Clayton, Euroclad

Technical Manager.

Test rig

The test rig was made available by Bret t Martin DaylightSystems and was generally in compliance with the rigdefined in ACR(M)001 : 2005. The purlins were 175/160,which have the necessary minimum I xx value of 235mm 4.Purlins were braced as required.

Constructions tested

Tests were carried out over a range of profiles and arange of purlin centres from 0.600m up to 2.1m, onsimulated hips and on simulated curved roof

arrangements.

Based on previous experience, dropping the bag near theunderlapping side lap of the sheets at midspan betweenpurlins was expected to be the most likely worst case,for all purlin spacings, and any failure was expected tooccur at the nearest end lap (downslope or upslope) orsheet end position of a multi-spanning sheet.

Testing was carried out to verify the worst case. Addit ional testing was carried out on profile variants to

establish the most effective solution, i.e. the end lap andsheet end fixing edge distance was varied, as was thesize of washer and number of fixings if necessary.

The length of the end lap, the number and location of thefasteners at both sheet ends and intermediate supportsand the fastener edge distance, are the usual criticalvariables. In some cases the washer size is also a criticalfactor. All tests used 5.5mm diameter fixings.

No seals were used at end or side laps in any of thetests, as any contribution they made to the strength couldnot necessarily be relied upon on site, e.g. if the sheetswere damp.

No spacer system was fitted as any contribution to linerperformance made by additional fixings through the linersheet may not always be present on site e.g. if the spacerbrackets were fitted later. In the case of external sheetsthe spacer system would have improved performance sowas not used to allow the worst case to be assessed.

Drawings for Euroclad non-fragile installations,can be found at: www.euroclad.com


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Table 2. Fixing specification of typical construction (carbon steel)

Purpose Gauge Description Fixing frequency

SFS fixings

Notes: 1. The above assumes normal U.K. urban conditions. If a more severe environment is anticipated, please refer to Euroclad, or the fixing manufacturer.2. All fixings must have a sealed washer and external fixings should also have a colour coded cap. 3. Equivalent products are available from several fixingmanufacturers. 4. If aluminium sheets are used all fixings should be stainless steel. 5. Position bracket in first valley that forms the underlapping side of the lap.

Fixing of liner sheet ends 1.2mm - 3.0mm SFS code SD3 - T15 - 5.5 x 25 1 per valley (for end laps)3.0mm - 12.5mm SFS code SD14 - T15 - 5.5 x 32 every other valley (for intermediate purlins)

Fixing of spacer bracket to sheeting rail 1.2mm - 3.0mm SFS code SD3 - 5.5 x 25 Typically 2 per bracket @ 1m centres3.0mm - 12.5mm SFS code SD14 - 5.5 x 32 (see note 5 below)

Fixing of weathersheet to rail SFS code SDP3 - T16 (or T19) - 5.5 x 25 1 per valley (for end laps)every other valley (for intermediate purlins)

Side stitching of outer sheet 1.2mm - 3.5mm SFS code SLP2 - T - A14 - 4.8 x 20 450mm centres

Purpose Gauge Description Fixing frequency

EJOT fixings

Fixing of liner 1.2mm - 3.0mm EJOT code LS25 1 per valley (for end laps)3.0mm - 12.5mm EJOT code HS38 every other valley (for intermediate purlins)

Fixing of spacer bracket to sheeting rail 1.2mm - 3.0mm EJOT code LS25 2 per bracket @ 1m centres3.0mm - 12.5mm EJOT code HS38 (see note 5 below)

Fixing of weathersheet to rail EJOT code JT2 x 25 1 per valley (for end laps)every other valley (for intermediate purlins)

Side stitching of outer sheet 0.5mm - 2.0mm EJOT code SF25 G16 450mm centres

1, 2 3mm Carbon steel fasteners Austenitic stainless steel fasteners

8/3, 13/3, Sinusoidal profile fasteners

Purlins (roof) Rails (wall) SD3 - T15 - 5, 5 x 60 - Hex head. Plus M6 x 28 x colour SX3/20 - 34 - S16 - 5, 5 x 52 - Hex head. Plus M6 x 28 x colourSelawasher and 28 x colour deep Selacover cap Selawasher and 28 x colour deep Selacover cap

Rails (wall) Wall (valley fix) SDP3 - T16 - 5, 5 x 25 x colour 5 x 3/10 - L12 - A12 - 5, 5 x 28 x colour

4 14mm Carbon steel fasteners Austenitic stainless steel fasteners

Purlins (roof) Rails (wall) SD14 - T15 - 5, 5 x 66 - Hex head. Plus M6 x 28 x colour SX14/38 - S16 - 5, 5 x 61 - Hex head. Plus M6 x 28 x colourSelawasher and 28 x colour deep Selacover cap Selawasher and 28 x co lour deep Selacover cap

Rails (wall) Wall (valley fix) SDP14 - T16 - 5, 5 x 36 x colour - Sela moulded head SX14/12 - L12 - A12 - 5, 5 x 38 x col-irius powder coated headTimber Carbon steel fasteners Austenitic stainless steel fasteners

Purlins (roof) Roof (crown fix) TDA - T - T16 - 6 5 x 76. Plus M6 x 28 x colour Selawasher TDA - S - S16 - 6, 5 x 76. Plus M8 x 28 x colour Selawasherand 28 x colour deep Selacover and 28 x colour deep Selacover

Rails (wall) Wall (valley fix) TPC - T T16 - 6, 3 x 38 x colour - Sela moulded head TPC - S - S16 - 6, 3 x 38 x colour - Sela moulded head

Stitching fasteners general fixing of flashings

SLP2 - A14 - 4, 8 x 20 x col SDL3 - L12 -T15 - 5, 5 x 25 x col SLP2 - S - A14- 4,8 x 20x col SXL2 - L12 - A14- 5,5 x 22x colSela moulded head Irius powder coated head Sela moulded head Irius powder coated head


18/44


Cut edge protection

Discussing the prospect of using pre-finished steelsheets for cladding buildings will invariably raise thequestion of cut edge corrosion, it is a natural concern.

A fear that many architects and design engineers haveexperienced is that a sheared edge of a pre-finished steelsheet will corrode when exposed to the atmosphere.

It is a chemical fact that when steel and zinc are in contactin the presence of moisture there is an automaticelectro-chemical action which slows down the corrosion.Cut edge protection is further enhanced by using aGalvalloy metalic coating instead of zinc. CorusColorcoat HPS200 and Colorcoat Prisma aremanufactured with Galvalloy metalic coatings asstandard. Because of this, Corus are able to includecover for cut edge protection for the life of the guarantee.

It is usually necessary during the course of cladding astructure that either the pre-finished steel sheet or theflashings will be cut on site. To ensure that the ability of

the zinc to protect the steel is not impaired, these cutsmust be achieved with the correct tools. Above all, heatmust not be created during the process because of therisk of damage to the zinc and therefore a correspondingreduction in the life expectancy of the roof or cladding.

However, the exposed edge may be treated with anapproved edge protection paint system to enhance itsresistance to atmospheric pollution. The edge referredto here is that defined by the profile shape in crosssection i.e. the cut end of the sheet. Painting the edgeswill considerably enhance the durability of the paintcoating and the substrate in the region of the cut edge

and will also reduce the possibility of pattern staining.

Suppliers who offer paint systems approved by Corusfor use with their products are listed below:

Becker Industrial Coatings LimitedGoodlass RoadSpekeLiverpool

L24 9HJ Telephone: +44 (0)151 448 1010

Akzo Nobel Coatings LimitedPO Box 37Crown HouseHollins RoadDarwenLancashireBB3 0BG

Telephone: +44 (0)1254 760760

Covac LimitedEagle HouseBilton WayLutterworthLeicestershireLE17 4JA

Telephone: +44 (0)1455 556631

The paint systems from these companies can beapplied to the area of the cut edge with a brush orother suitable means.

Cantilever

Projecting cantilevers should be restricted to 400mm.

Penetrations

Maximum size of penetration without additional structuralsupport is 300mm.


19/44


Table 3. Weights of profiled sheets and their calculations

Typical fixing layout

Typical arrangement for Euroclad 32/1000 and 19/1000liner sheets, using a rail and bracket spacer system.

0.4mm 1000/19 1000 1115 Liner 3.498 3.498 572 286

0.5mm 1000/19 1000 1115 Liner 4.372 4.372 457 229

0.7mm 1000/19 1000 1115 Liner 6.121 6.121 327 163

0.5mm MM10 1000 1230 HPS200 /Prisma /PVDF/ Liner 4.823 4.823 415 207

0.7mm MM10 1000 1230 HPS200 /Prisma /PVDF/ Liner 6.753 6.753 296 148

0.4mm 914/20 914 1025 Liner 3.518 3.215 622 311

0.4mm 1066/20 1066 1200 Liner 3.531 3.764 531 266

0.5mm 1066/20 1066 1230 HPS200 /Prisma /PVDF/ Liner 4.525 4.823 415 207





0.9mm 1000/32 1000 1230 HPS200 /Prisma /PVDF/ Liner 8.682 8.682 230 1150.5mm MW5 1000 1230 HPS200 /Prisma /PVDF/ Liner 4.823 4.823 415 207

0.7mm MW5 1000 1230 HPS200 /Prisma /PVDF/ Liner 6.753 6.753 296 148

0.9mm MW5 1000 1230 HPS200 /Prisma /PVDF/ Liner 8.682 8.682 230 115




0.7mm SF500 500 695 HPS200 /Prisma /PVDF 7.686 3.843 524 262

0.7mm Euroseam 400 587 HPS200 /Prisma /PVDF 8.056 3.223 621 310

0.5mm 131 / 2 /3 990 1230 HPS200 /Prisma /PVDF 4.872 4.823 415 207



Gauge ProfileCoverwidth

Coilwidth

Corus Colorcoatpre-finished steel product kgs/m 2

Steelkgs/Linear metre

L/m per2 tonne bundle


Densitykgs/m2

Steel7842.636

Mill finishaluminium

2715.00

One side coatedaluminium2745.000

Gauge m2 tonne m 2 tonne m 2 tonne

0.40 318.770 920.810 910.747

0.50 255.016 736.648 728.597

0.55 231.833 669.680 662.361

0.60 212.514 613.874 607.165

0.65 196.166 566.653 560.460

0.70 182.154 526.177 520.427

0.90 141.676 409.249 404.776

1.20 106.257 306.937 303.582


20/44


0.9mm 914/38 914 1230 Stucco 3.288 3.006 665 333

0.9mm 1000/32 1000 1230 Stucco 3.006 3.006 665 333

0.9mm MW5R 1000 1230 Stucco 3.006 3.006 665 333

0.9mm Euroseam 300 487 Stucco 3.967 1.190 1681 840





Coilwidth Coating kgs/m2

Aluminiumkgs/Linear metre



0.5mm MM10 1000 1230 ARS / PVDF 1.688 1.688 1185 592

0.7mm MM10 1000 1230 ARS / PVDF 2.363 2.363 846 423

0.9mm MM10 1000 1230 ARS / PVDF 3.039 3.039 658 329

0.5mm 914/20 914 1025 ARS / PVDF 1.539 1.407 1422 711

0.5mm 1066/20 1066 1230 ARS / PVDF 1.584 1.688 1185 592

0.5mm 1000/32 1000 1230 ARS / PVDF 1.688 1.688 1185 592

0.7mm 1000/32 1000 1230 ARS / PVDF 2.363 2.363 846 423

0.9mm 1000/32 1000 1230 ARS / PVDF 3.039 3.039 658 3290.9mm MW5 1000 1230 ARS / PVDF 3.039 3.039 658 329

0.9mm Euroseam 300 487 ARS / PVDF 4.010 1.203 1662 831




Coilwidth Coating kgs/m2

Aluminiumkgs/Linear metre



Rail and bracket systems

Gauge System WeightComponent Unit

1.6mm Eurobar Rail 1.080 kgs Per metre

1.2mm Eurobar Bracket 83mm 0.054 kgs Each

1.2mm Eurobar Bracket 120mm 0.080 kgs Each1.2mm Eurobar Bracket 150mm 0.102 kgs Each

1.2mm Eurobar Bracket 170mm 0.116 kgs Each

Gauge System WeightComponent Unit

1.5mm Eurobar Extra 1.2m Bar 1.920 kgs Each

1.5mm Eurobar Extra 2.4m Bar 3.840 kgs Each

1.5mm Eurobar Extra 3.6m Bar 5.760 kgs Each1.5mm Eurobar Extra Bracket 135mm 0.290 kgs Each

1.5mm Eurobar Extra Bracket 185mm 0.320 kgs Each

1.5mm Eurobar Extra Bracket 200mm 0.330 kgs Each

1.5mm Eurobar Extra Mast 135mm 0.230 kgs Each





21/44


Handling and storage

The following comments refer to the trapezoidal profilesand not to Secret fix or Euroseam, which have particularpacking/handling notes in the relevant section.

Every profiled sheet and flashing is carefully inspectedbefore despatch and consignments are packed in edgewrapped strapped bundles. It must be emphasised thatthese sheets and flashings are quality products and

should be handled accordingly.

On arrival at the site, care should be taken in theoffloading; avoid unnecessary handling of the sheets,lifting (not dragging) them directly off the bundles.

When hoisting bundles and sheets into position, protectthe edges and ensure that the pressure across the sheetsand flashings does not cause distortion. Use rope, notchains, for hoisting.

Note: Euroclad pallets are not suitable for crane off-load.

If a protective, strippable film has been applied

to the coating, this should be removed from theunderlap edge prior to fixing and the remainder removed within two weeks.

Failure to observe simple but essential precautions whenstoring and handling galvanised and pre-finished steelroofing and cladding sheets on site, leads to repeatedcomplaints of corroding and damage. Investigation showsthat in almost every case damage is due to negligenceprior to use. The most common fault is exposing stackedsheets to the weather for weeks, even months oftenlying in long grass. Avoid careless handling.

To ensure that sheets do not deteriorate when

stored on building sites, the following precautionsare essential:

Do not leave uncovered stacks lying in the open.Store under cover and away from open doorways.

If stacks cannot be kept under cover, erect a simplescaffolding around them and cover with a waterproof sheet, tarpaulin or polythene, but leave space betweencover and sheets to allow air to circulate.

Store stacks off the ground and on a slope, so that shouldrain penetrate the covering, the water will drain away.

Inspect the storage site regularly to ensure that

moisture, despite the above precautions, has notpenetrated the stock.

Do not store sheets where people will walk across them.

Observe these precautions and they will save youtrouble, time and money.

Guidance on breather membranes

It is no longer necessary to install a breather membranein the majority of twin skin metal roofing claddingapplications.

This is the latest advice from the Metal Cladding andRoofing Manufacturers Association (MCRMA) and isthe result of work which has recently been carried out

by the Building Research Establishment (BRE),in collaboration with the MCRMA, to examine in detailthe factors that determine the risk of condensationwithin twin skin metal roofs.

This work has demonstrated that, if a well sealed liner isused in conjunction with vented fillers for the outer sheet,only small amounts of condensation may occur on theexternal sheet over the winter and there will not besufficient accumulation to cause dripping or running.

Therefore, so long as the cladding is installed with a highstandard of workmanship with appropriate detailing,especially a well sealed liner, it is not necessary to install

a breather membrane except in cases where there islikely to be an unusually high internal moisture load.

Previously, the best practice advice contained in thesecond edition of the BRE publication Thermal insulation:avoiding risk (BR 262) published in 1994, suggested thata breather membrane be placed between the insulationand the outer skin of a twin skin metal roof, in order toprevent any dripping or running of condensed water ontothe insulation.

This was based on the best informat ion available at thetime, which suggested that although the primary means

of preventing condensation problems was a well sealedliner sheet or vapour check below the insulation, abreather membrane would provide a second line of defence. This would be especially important in the caseof buildings with high internal moisture loads such asswimming pools.

This latest work will be taken into account in the newversion of Thermal Insulation: Avoiding Risks which hasbeen prepared to accompany the new edition of Approved Document L2 of the Building Regulations.

Building designers and building control officers may welllike to take this latest guidance into account in bothcurrent and future projects.


22/44


23/44

DESIGN AND INSTALLATION RECOMMENDATIONS M R 2 1

Wind loads (BS 6399 : Part 2)

The wind load affecting a particular construction may becalculated with careful reference to the above standard.

At critical points in a structure the suction loads createdoften exceed all other imposed loads. In thesecircumstances it is a combination of the profiles strengthand the number and strength of the fasteners whichbecome critical. It is often necessary to increase the

specification of the fasteners in the high load areas.

Cleaning of pre-finished steel

There are stages during its life cycle that a pre-finishedsteel clad building may need cleaning. It is often the casethat during the construction, building debris of varioustypes will be deposited both on the roof and walls. Forthe pre-finished steel to achieve its anticipated life to firstmaintenance all debris must be cleared as soon aspossible. If the building is in a particularly dirtyenvironment it may need cleaning during its life.

There is a requirement for many pre-finished steels tohave annual inspections and maintenance to maintainthe validity of the guarantee. However, Corus ColorcoatHPS200 does not require this and is maintenance freefor the lifetime of its guarantee.

Swarf

It is imperative that all swarf is removed from the pre-finished surfaces. The heat imparted to the swarf couldhave melted the paint and zinc and the remaining coldreduced mild steel will rut very quickly upon exposure tothe elements. In any case, if the swarf is not removed itrusts and gives the effect that the sheet itself isdeteriorating.

All surfaces must be cleaned and particular at tentionpaid to surfaces where the swarf could accumulate,such as drip detail.

Cement on pre-finished steel

Often deposits of cement are inadvertently left on the pre-finished steel cladding. Wet cement/mortar mixes arevery alkaline during the wet/curing stage, and may leaveresidual staining on the surface, and more particularlyattack the exposed, sheared edge.

Immediate removal is essential. Thick deposits should be

removed carefully with a blunt wooden scraper, takingcare not to damage the surface.

Removal of residual mortar stains should be accomplishedwith neat vinegar and a soft scrubbing brush.

Finally, all areas should be rinsed off with cold clean water.

General debris

Often left on roofs, their danger is that the damagecaused prevents drainage and encourages ponding.Continued ponding will have a detrimental effect on thelife expectancy of the pre-finished steel finishes.

Once the roof/walls are fixed all should be rinsed with

cold clean water and all debris removed.

Other deposits

No matter what, solvents and abrasive type cleanersshould be avoided in cleaning any pre-finished steelsurface. Caulking compounds, tar and similar substancesmay be removed with mineral spirits. Always cleansurfaces down from top to bottom and follow immediatelywith a thorough rinsing with clean fresh water. It must bepointed out that over cleaning or scrubbing can do moreharm than good.

Repair to the surface

If scratches are made in the pre-finished steel surfacethese are easily repaired with the application of air dryingplastisol, polyurethane or PVDF touch-up paint, availablefrom Euroclad. It must be emphasised that these paintsare only for touching in small areas and are not suitablefor application over large areas.

There are few exterior materials whose appearance andperformance will not benefit from regular inspection,together with any maintenance that might be necessaryat the time. Such activities will repay the careful buildingowner and the occupier by giving them the best possible

performance from the product.

Washing

Regularly wash away dirt and debris that have not beenremoved by natural rainfall.

Areas of cladding that lie beneath overhanging buildingdetails, such as those beneath gutters, for example, areparticularly susceptible to a build-up of dirt. Suchaccumulations may hold water and pollutants, which canlead to 'wet poultice' corrosion.

Wash cladding with fresh water, using a hose and a

soft cloth.

In areas where heavy industrial deposits dull the surface,use a good quality household detergent (10% solution inwater) or a proprietary cleaner (follow manufacturer'sinstructions). Always rinse thoroughly with clean water.

Inspection and maintenance


24/44


Guidelines

1 Do not use a concentration of detergent greaterthan the 10% solution mentioned above nor aconcentration of a proprietary cleaner greater thanthat recommended by the manufacturer.

2 Do not use organic solvents or abrasive cleaners.

3 Mineral spirits may be used to remove caulkingcomponents, tar, and similar substances, but thesurface must then be washed immediately andthoroughly in the manner described above.

4 Always wash coated surfaces from top to bottom.

5 After washing, always rinse the cladding immediatelyand thoroughly to remove all detergents and cleaners.

6 Do not over-clean or scrub the surface since that canspoil the high-quality finish.

Removing mould

Corus Colorcoat products have been speciallyformulated to resist fungal growth and therefore thisshould not be a problem in most geographical areas.

However, some types of local environment are particularlyconducive to mould growth, e.g. areas of wet, dark, orwooded surroundings or low-lying marshland. In theseareas, mould will grow, even on inert materials suchas glass.

Mould can be removed by treating the affected surfacewith a basic solution of the ingredients shown below (byweight), which should be available from local chemicalsuppliers. Before applying the mixture, wash the surfaceof the cladding first, as described under Washing above.

Then apply the mixture to all surfaces using a low-pressure spray or cloth. Rinse the cloth frequently andchange it and the mixture as necessary to prevent anygrit or abrasive particles scratching the building. Allsurfaces must be rinsed with cold water within 24 hoursof applying the mixture.

The mixture

You should refer to the manufacturers ' health and safetyinformation before using the chemical ingredients listedbelow.

Good quality household detergent or proprietary cleaner 0.5

Trisodium phosphate 3.0

5% sodium hypochlorite solution 25.0

Fresh water 71.5

Total 100.0

Table 5. Annual inspection

* These items should be checked as soon as possible after the building has been erected and as part of the annual inspection.

Table 4. Ingredient by weight

Check for Potential problems Action

Blocked gutters They can cause overflow into the building Remove debris

Build-up of debris on sheets Such debris retains water and pollutants, forming a 'poultice', Remove the debris and, if necessary, wash the area aswhich can cause corrosion described under Washing

Retention of dirt in areas of cladding not This detracts from the appearance of the building and, Wash the area as described under Washingwashed naturally by rainwater, if ignored, can cause the paint coating to break downe.g. below overhangs

Mould growth This rarely occurs, but can arise in extreme conditions Wash the area and treat it for mould growth as describedunder Removing mould

Local damage* If the damage has broken through the paint coating, Assess the extent of the damage and either repair it withthe steel substrate may be exposed to attack touch-up paint (see page 23) or replace the sheets through

the original cladding supplier

Swarf (from drilling), rivet stems, and These items themselves can corrode and stain the Remove the debris and, if necessary, wash the sheetother fixing debris* sheet surface surface as described under Washing

Faulty or inappropriate fasteners* Such fasteners can cause leaks or can corrode and stain Replace the fasteners and any missing capsthe sheet surface, or both

Areas at cut edges or surfaces that need Use specialist contractors and approved maintenance paintsover-painting from listed suppliers (see page 16)


25/44

INSPECTION AND MAINTENANCE 2 3

Touch-up painting

Slight scuffs are best left untreated. If the sheet hasbeen scratched down to the substrate, it should berepaired with standard touch-up paint. Ensure that theapplied paint is no wider than the original scratch.Since touch-up paints are air-drying, they will, over time,change colour differently from the original paint coating,so keep the applied area as small as possible.

Suppliers of complementary products

Cleaners:

British Flowplant GroupUnits 11-15Stadium CourtBarbot Hall Industrial EstateRotherhamSouth YorkshireS62 6EW

Telephone: +44 (0)1709 838308Perpetual Environmental LimitedHayden LaneNuffieldOxonRG9 5TX

Tel: +44(0)1491 641945

Touch-up paints:

Breakwells Paints1 Harden RoadLeamoreWalsallWest MidlandsWS3 1EL

Telephone: +44 (0)1922 400444

This company can arrange a technical visit to supply aspecification and can also recommend contractors whocarry out this work.

Over-painting:

Akzo Nobel Industrial CoatingsPO Box 37Crown HouseHollins RoadDarwenLancashireBB3 0BG

Telephone: +44 (0)1254 760760

D.R. Chemicals Viking WayWinchwen Industrial EstateSwanseaSA1 7DA

Telephone: +44 (0)1792 701135

McKLordsUnits 7 & 8

Tirllwyd Industrial EstateKinmel BayBorough of ConwyLL18 5JA

Telephone: +44 (0)1745 585995


26/44


27/44

DESIGN AND INSTALLATION RECOMMENDATIONS 2 5

Noise and its control is becoming an increasinglyimportant aspect of building design. The purpose of this section is to highlight that Euroclad are able toadvise on the performance of various configurations of cladding systems with regard to their acoustic properties.

Research

All of the information referred to in this section is basedupon the research carried out by Building AcousticsGroup, Department of Applied Acoustics, University of Salford.

What is noise?

Noise is sound which can be annoying, which caninterfere with enjoyment of normal activities, and cansometimes be harmful.

Sound propagates through the air as a pressuredisturbance or wave, superimposed on the atmosphericpressure.

In general terms the greater the variation in pressure,the louder the sound.

The pitch, or frequency, of the sound is determined bythe spacing of the waves (or its wavelength).

Measurement

Sounds are measured using sophisticated instrumentswhich act approximately in the same way as the humanear, but convert the incoming pressure waves into anelectrical signal which can be read on a meter.

The range of sound pressures is very large, approximatelyin the ratio 1 to 10,000,000 from the quietest to the

loudest sounds.Meters are calibrated to a logarithmic scale, reading indecibels (dB) to give more meaningful values, especially atthe lower levels.

The scale below shows typical Sound Pressure Levels(SPL) in dB and the corresponding actual pressures forvarious well known noises.

Please refer to MCRMA Technical Paper 8 forfurther guidance.

Acoustic performance

Table 6. Typical sounds and their dB ratings

Sound pressurelevel*dB

PressureN/m2 x 10

Small jet at take off 120 20,000,000Sheet metal shop near grinder 110

Noisy factory with riveting 100 2,000,000

Heavy lorry at 5m 90

Busy street or workshop 80 200,000

Radio/TV in living room 70

Restaurant, store, general office 60 20,000

Quiet office 50

Outside residential area at night 40 2,000

Inside bedroom at night 30

Recording studio 20 200

Sound proof room 10

Threshold of hearing 0 20

*Note X dB = 20 log P/P where P = 20 x 10 N/m2.


28/44


The acoustic performance of these constructions isaffected not only by the performance of the individualmetal sheets but also by the insulation material and theconstruction details (see Figures 6 and 7).

Figure 6. Double skin system Figure 7. Composite panel

Double skin constructions

Most metal cladding is either built up on site to form aninsulated double skin system or it may be supplied as afactory made composite panel.


29/44

ACOUST IC PE RFORMANCE 2 7

Mineral fibre density andsystem comparison

Soft insulation such as mineral wool can act to dampenout vibration in the panel, but it should not be packed tootightly or it will provide bridging to other components.

Rigid foam insulation used by competitors such as infactory made or site assembled composite panels, hasan acoustic bridging effect so its acoustic insulationvalue is relatively low (typically Rw 26 dB).

Filling the profile completely with densely bonded

material wool slabs can also adversely affect the

acoustic insulation of the construction, as will fixing

details and the cladding span.

23 kgm 90 kgm 100 kgm

Composite panel Built-up system

Figure 8. Comparing the effect of density and softness of mineral fibre insulation70

60

50

40

30

20

10

S R I v a

l u e s

( d B )

1 0 0 1 2 5 1 6 0 2 0 0 2 5 0 3 1 5 4 0 0 5 0 0 6 3 0 8 0 0 1 0 0 0 1 2 5 0 1 6 0 0 2 0 0 0 2 5 0 0 3 1 5 0 4 0 0 0 5 0 0 0

Frequency (HZ)

Typical Trapizodal Wall (Scotland) Acoustic Performance (.30 'U' Value)

7

60

20

1

100 125 160 200 250 315 400 500 630 800 1000 1250 1600 2000 2500 3150 4000 5000

S R I

Frequecy (HZ)

Figure 9. Comparing a site assembled system and a composite panel6

50

40

30

20

10

Frequency (HZ)

S R I v a

l u e s

( d B )

1 0 0 1 2 5 1 6 0 2 0 0 2 5 0 3 1 5 4 0 0 5 0 0 6 3 0 8 0 0 1 0 0 0 1 2 5 0 1 6 0 0 2 0 0 0 2 5 0 0 3 1 5 0 4 0 0 0 5 0 0 0


30/44

Perforation

Ideally the less the mechanical linkage or bridgingbetween the individual layers of the construction andbetween the cladding and the support structure, thehigher the acoustic insulation. Any fixings, therefore,have an adverse effect on the acoustic performance, butare clearly essential for the installation of the structure.Point fixing, such as widely spaced screws, is better

acoustically than a line of closely spaced rivets.However, if there is any distortion of the laps of thesheets between fixings, thus creating gaps, the highfrequency noise insulation can be reduced.

The examples above illustrate the way in which theacoustic insulation performance of the cladding can beaffected by materials and design. In some situations itis necessary to influence the internal acoustics of thebuilding by reducing reverberation, either to control thebuild up of noise, or to make the space more acceptablefor a particular activity.

This can be achieved by perforating the liner to al low thenoise to be absorbed by the fibrous insulation. Generally,to achieve absorption across the widest possiblefrequency range, a minimum perforation ratio (holearea/sheet area) of approximately 30% should be used,spread evenly across the whole surface. Eurocladrecommend a pattern of 3mm holes on 5mm staggered

centres (see illustration). If the ratio is less than this, thehigh frequency absorption is reduced significantly.

Note that this amount of perforation will reduce thestrength of the liner and the use of thicker material suchas 0.7mm should be considered.

An example of the absorpt ion coefficients for aconstruction with a perforated liner is shown inFigure 10.


Example of standard perforation pattern


31/44

ACOUST IC PE RFORMANCE 2 9

Note: covering the absorbent material, or using a vapourcontrol layer between the perforated liner and the

acoustic insulation can adversely affect the absorptioncharacteristics.

Perforating the liner may also reduce the acousticinsulation value (i.e. for transmitted sound) for theconstruction as shown in Figure 11.

Single and double skin system comparison

Technical assistance

As part of the research, Salford have created a computerprogramme which will allow the performance of variousproposed constructions to be compared.

Single skin steel sheet Double skin system with fully perforated liner

30% perforated liner Solid liner

Figure 10. Comparing sound absorbtion coefficients of a single skin cladding with perforated liner1.0

0.8

0.6

0.4

.

.

Frequency (HZ)

A b s o r b t i o n

c o e

f f i c i e n t

C

1 0 0 1 2 5 1 6 0 2 0 0 2 5 0 3 1 5 4 0 0 5 0 0 6 3 0 8 0 0 1 0 0 0 1 2 5 0 1 6 0 0 2 0 0 0 2 5 0 0 3 1 5 0 4 0 0 0 5 0 0 0

Figure 11. Effect of perforated liner on sound insulation of a double skin system70

60

50

40

30

20

10

S R I v a

l u e

s ( d B )

1 0 0 1 2 5 1 6 0 2 0 0 2 5 0 3 1 5 4 0 0 5 0 0 6 3 0 8 0 0 1 0 0 0 1 2 5 0 1 6 0 0 2 0 0 0 2 5 0 0 3 1 5 0 4 0 0 0 5 0 0 0

Frequency (HZ)


32/44

Trapezoidal acoustic performance


914/38mm 0.7mm, 170mm (27kgs @0.040), 0.4mm 20mm Steel Liner (Weighted SRI Rw = 43.6 dB) 1000/32mm 0.7mm, 170mm (27kgs @0.040), 0.4mm 19mm Steel Liner (Weighted SRI Rw = 42.9 dB)

Figure 12. Typical trapezoidal roof acoustic performance (.25 U-value)80

60

5

40

20

10

S R I v a

l u e s

( d B )

1 0 0 1 2 5 1 6 0 2 0 0 2 5 0 3 1 5 4 0 0 5 0 0 6 3 0 8 0 0 1 0 0 0 1 2 5 0 1 6 0 0 2 0 0 0 2 5 0 0 3 1 5 0 4 0 0 0 5 0 0 0

Frequency (HZ)


Figure 13. Typical trapezoidal wall acoustic performance (.35 U-value)80

70

60

50

40

30

20

10

0

S R I v a

l u e s

( d B )

1 0 0 1 2 5 1 6 0 2 0 0 2 5 0 3 1 5 4 0 0 5 0 0 6 3 0 8 0 0 1 0 0 0 1 2 5 0 1 6 0 0 2 0 0 0 2 5 0 0 3 1 5 0 4 0 0 0 5 0 0 0

Frequency (HZ)


Figure 14. Typical trapezoidal wall (Scotland) acoustic performance (.30 U-value)

70

60

50

40

30

20

10

S R I v a

l u e s

( d B )

1 0 0 1 2 5 1 6 0 2 0 0 2 5 0 3 1 5 4 0 0 5 0 0 6 3 0 8 0 0 1 0 0 0 1 2 5 0 1 6 0 0 2 0 0 0 2 5 0 0 3 1 5 0 4 0 0 0 5 0 0 0

Frequency (HZ)


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Calculation of U-values

1 Approved Document L2 requires that the U-valuesof metal site assembled and composite panel wallsand roofs must be less than or equal to 0.35 W/m 2K and 0.25 W/m 2K respectively (the correspondingvalues in Scottish Technical Standard J are 0.30W/m 2K and 0.25 W/m 2K). These values includeassociated components such as gutters and smoke

vents, however, rooflights, windows and doors haveseparate values.

2 Because the method for calculating U-valuescontained in BS EN ISO 6496 and CIBSE Guide Adoes not apply to metal roofing and cladding systems,more complex methods must be used.

3 If the construction is one of those covered in BRE IP5/98, the U-value can be obtained from the graphsor other information in the IP and corrected for airspaces and compression of the insulation by theprofiles using the equations in the IP.

4 If the component contains independent linearfeatures that can be represented by a series of two-dimensional models, use a two-dimensionalmodel and combine the results from the differentmodels.

5 If the component contains repeating point thermalbridges, such as clips, develop a three-dimensionalmodel to calculate the heat flows and then theU-value.

Thermal bridging

1 Approved Document L2 requires that the buildingfabric should be constructed so that there are nosignificant thermal bridges or gaps in the insulationlayer(s) within the various elements of the fabric, atthe joints between elements and at the edges of elements such as those around window and dooropenings. It is also necessary to account for

penetration of the insulated envelope by featuressuch as safety harness posts or rafters which projectto support a canopy or gutter.

2 It is necessary to consider both the risk of condensation on each individual thermal bridge andthe effect of the increased heat loss through thermalbridges on the overall heat from the building.

3 If a detail contains metal components crossing theinsulation that would not otherwise be present in aplane element, surface condensation may occur inhumid environments. The severity of the bridge, and

therefore the risk of condensation, is determined bythe F-factor, which is calculated by modelling thestructure. If this type of thermal bridge is to beincluded in a building which is likely to have a humidinternal environment, consideration should be givento redesigning the detail.

4 It is also necessary to calculate the contribution of the thermal bridges to the overall heat loss from thebuilding by using the linear thermal transmittance( -value) and then following the procedures specifiedin BRE IP17/01. If the total heat loss through thethermal bridges is greater than 10% of that through

the plane areas, individual details must be modifiedto reduce the loss through the bridges.

5 The parameters needed to comply with Part L viaIP 17/01 (the F-value and the -value) are given inthe MCRMA Technical Paper 14 for a range of details that should cover most metal clad buildings.Means of improving the thermal performance of eachdetail are presented. It will be necessary to use athree-dimensional thermal model to calculate theF-value and the -value for all other details.

The building regulations

*Source: Corus Colorcoat Technical Paper, E nd of life option s for pre-fi nishedsteel buildings, 2006.


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Air permeability

Approved document L (2006)

Air-tightness is measured in m 3 of air per hour per m 2

of building envelope at an applied pressure of 50 Pa. The area of the building envelope includes the walls,roof and floor slab. In practice, the floor slab can beconsidered air-tight.

The concept of air-tightness was first introduced intoBuilding Regulations in England and Wales in the 2002revision of: Approved Document L. In this document,a maximum allowable air leakage rate of 10m 3 /h/m 2

was introduced for all buildings other than dwellingsgreater than 1000m 2.

The 2006 update to Part L has extended this further. All buildings must be pressure tested, unless the floorarea is less than 500m 2, when a default value of 15m 3 /h/m 2 can be used. For buildings over 500m 2,a maximum reasonable design limit for air tightness is

10m3 /h/m

2. The new requirements are less prescriptive

than 2002. However, it will be difficult to meet theoverall building CO 2 emission rate without a reasonablyair-tight building envelope.

Air-tightness is tested using a number of largemobile fan units, to pressurise the building to 50 Pa.

The volume of air leakage is divided by the cladding(including floor slab) area.

Achieving air-tightness

In a typical pre-finished steel-clad building, the air-tightness barrier is provided by the interior, or liner,side of the envelope. While the outer sheet of aninsulated envelope will provide weather protection,and will be sealed in order to prevent water leaks,

it is important that it is not relied upon for air-tightness.

The first step in constructing an air-tight building,is to identify the liner as the air-tightness barrier andensure this is focused in the design and constructionof the building envelope. This system can provideextremely good air-tightness, using good detailingand construction.

Air-tightness, for a bui lt-up system, is achieved by theliner sheet. Sealant tapes, or beads, are used to sealthe overlap joints between adjacent sheets. Theinsulation cavity is ventilated, through the ribs of the

external profiled sheet, to minimise condensation risk.

*Source: Corus Colorcoat Technical P aper, En d of life options for pre-fi nishedsteel buildings, 2006.


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End laps

End laps are formed where the profiled edge of onesheet overlaps the edge the adjacent sheet. Liner sheetsare typically 0.4mm, or 0.7mm gauge. The joint issealed using a sealant bead, which is placed inside theoverlap joint.

Fixings should be installed in the trough of each profileto provide compression of the sealant bead.

The use of a good quality sealant bead will produce agood quality air resistant joint.

Table 9. Built-up systems recommended joint sealing practice

Joint details Recommendation Leakage rate m 3 /h/m

Side lap joint External sealant tape


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THE BUI LDING REGULATIONS 3 5

Conclusion

In summary, it is worth remembering that steel is aninherently air-tight material, so the only air-leakage pathsin a steel building envelope are where there are holes leftat junctions. Adopting the approaches detailed in thispublication should minimise holes at the majority of

junctions. It should be noted, however, that a targetair-leakage rate of 10 5 or even 3m 3 /m 2 /h allows, on

average, a hole of 700mm2

, 380mm2

or 200mm2

forevery 1m.

Given that the target air-tightness is for the wholebuilding (including all openings, interfaces, floors, roof and walls). it is essential that the techniques describedhere are adopted for the areas which are relatively easyto control, since holes will inevitably appear elsewherein the construction.

Experience has shown that with close attention todetail, steel clad buildings should have no difficultyachieving air-leakage rates of no more than 5m 3 /m 2 /h,and often have even less than 3m 3 /m 2 /h. However,air-leakage is highly dependant on building geometry.Simple, large buildings have proportionately lesspotentially-leaky interfaces than more complex,small ones.


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Corus Colorcoat HPS200 and Colorcoat Prisma pre-finished steel in Blue, Sirius and Goo sewing Grey.

Corus Colorcoat HPS200 pre-finished steel in Augusta G reen.


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Colorcoat productsand services

To ensure the long-term performance andappearance of the building, it is important that thepre-finished steel product is specified alongsidethe cladding system.

Corus Colorcoat Products and Services

The Colorcoat brand provides the recognised mark of quality and metal envelope expertise exclusively fromCorus. Over the course of 40 years Corus has developeda range of technically leading Colorcoat pre-finishedsteel products which have been comprehensively testedand are manufactured to the highest quality standards.

These are supported by a range of services such ascomprehensive guarantees, colour consultancy andtechnical support and guidance.

Colorcoat HPS200

Exclusive coating technology, superior performance andthe unique Confidex Guarantee make ColorcoatHPS200 the most specified pre-finished steel product inEurope for roof and wall cladding. Now maintenance freefor up to 30 years.

Colorcoat Prisma

The ideal choice to deliver eye-catching buildings thatwill stand the test of time. Technically and aestheticallysuperior to PVDF (PVF2), Colorcoat Prisma is readilyavailable in the most popular solid and metallic colours.

All backed up with the unique Confidex Guaranteeproviding cover for up to 25 years on walls.

Repertoire Colour Consultancy

The Repertoire Colour Consultancy can advise oncolours and colour strategies using a range of standardshades, as well as discussing individual bespoke colourrequirements. Corus can match almost any shade fromphysical swatches to commonly used references suchas RAL, NCS and British Standard and more unusualstandards.

Confidex Guarantee

Offers the most comprehensive guarantee for pre-finishedsteel products in Europe and provides peace of mind forup to 30 years. Unlike other guarantees, Confidex

covers cut edges for the entirety of the guarantee periodand does not require mandatory annual inspections.

Confidex Sustain

Provides a combined guarantee which covers thedurability of the Colorcoat pre-finished steel productand makes the pre-finished steel building envelopeCarbonNeutral the first in the world. Unavoidable CO 2emissions from the pre-finished steel cladding systemincluding fixings and insulation, are measured from cradleto grave and the impact offset. More than just offsetting,the aim is to encourage specification of the mostsustainable pre-finished steel products and claddingsystems.

Colorcoat Building manual

Developed in consultation with architects and otherconstruction professionals, the Colorcoat Buildingmanual incorporates over 40 years of Colorcoat

expertise. It contains information about sustainabledevelopment and the creation of a sustainablespecification.

Colorcoat Technical papers

Working closely with the Corus Colorcoat Centre for theBuilding Envelope based at Oxford Brookes Universityand the Steel Construction Institute, Corus has produceda number of technical papers. These address keyconstruction issues such as the creation of an airtightbuilding envelope and end of life options for pre-finishedsteel cladding systems.

For more information about Corus Colorcoat

products and services visit www.colorcoat-online.comor call the Colorcoat Connection helpline on+44 (0)1244 892434.

Colorcoat, Colorcoat Connection, Confidex, Confidex Sustain, Galvalloy, HPS200, Prisma and Repertoire are trademarks of Corus.


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Recommended good practice for daylighting in metal clad buildings MCRMA Paper Number 1

Curved sheeting manual MCRMA Paper Number 2

Secret fix roofing design guide MCRMA Paper Number 3

Metal wall cladding detailing guide MCRMA Paper Number 5

Profiled metal roofing design guide MCRMA Paper Number 6

Acoustic design guide for metal roof and wall cladding MCRMA Paper Number 8

Flashings for metal roof and wall cladding: Design, detailing and installation guide MCRMA Paper Number 11

Fasteners for metal roof and wall cladding: Design, detailing and installation guide MCRMA Paper Number 12

Guidance for the design of metal roofing and cladding to comply with Approved Document L2 : 2001 MCRMA Paper Number 14

Guidance for the effective sealing of end lap details in metal roofing constructions MCRMA Paper Number 16

References

Metal cladding: Assessing thermal performance BRE IP 5/98

Assessing the effects of thermal bridging at junctions and around openings BRE IP 17/01

Conservation of fuel and power in dwellings Building Regulations AD L1

Conservation of fuel and power in buildings other than dwellings Building Regulations AD L2

Conservation of fuel and power Part J - Scotland

Creating an air-tight building envelope Colorcoat

Technical paper


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Notes and contacts


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Euroclad LimitedWentloog Corporate Park Cardiff CF3 2ER

Telephone +44 (0 )29 2079 0722Facsimile +44 (0)29 2079 3149E-mail [email protected] www.euroclad.com

Euroclad (Ireland) LimitedUnit 4Newhall Industrial EstateNaasCo. Kildare

Telephone 00 353 (0) 45 435 470Facsimile 00 353 (0) 45 435 472Internet www.euroclad.com

euroclad guide to design and installation of trapezoidal systems

Documents