CI/SfB (4-) Rf9 September Dry fix and ventilation systems.

Transcription

1 CI/SfB (4-) Rf9 September 2013 Dry fix and ventilation systems Including accessories 45

2 Today s roofs need to be weatherproof and look good, as well as providing adequate ventilation. For you, they also need to be quick and economical to install, and for the building owner they require minimal on-going maintenance but maximum durability and long life. 2 Dry fix and ventilation systems

3 Contents 4-5 System selector 6-7 Ventilation and dry fix system selector 8-9 Eaves vent systems Dry verge systems Ventilated dry ridge systems 21 Top abutment ventilation system Dry hip systems Dry valley systems Roof slope systems Ridge vent terminals Condensation and ventilation guidance Services Dry fix and ventilation systems 3

4 Eaves vent systems Dry hip systems 10mm eaves vent system pages mm eaves vent system pages 8-9 HipFast pages Dry hip system pages Roof slope systems tile vent terminal page 29 Contour and in-line vents pages Tile ventilation terminals pages Ridge vent terminals Ridge vent terminals pages Gas vent ridge terminal page 37 Ventilated dry ridge systems RidgeFast pages Ventilated dry ridge system pages Fibre cement slate ridge with ridge roll page 21 Ventilated dry mono ridge system pages Dry fix and ventilation systems

5 Dry verge systems dry verge system pages Edgemere dry verge system pages Slate dry verge system pages Cloak verges pages Dry valley systems GRP dry valley pages GRP slate dry valley systems page 28 Abutments Top abutment ventilation system page 21 The Universal ranges offer you a 'system in a box' complete with dry fix and ventilation solutions suitable for all Marley Eternit roofing products and with other manufacturers tiles and slates. Dry fix and ventilation systems 5

6 Ventilation & dry fix system selector Tile Concrete Clay Fibre cement Edgemere range plain tiles plain tiles slates roofing accessories 10mm eaves vent system 25mm eaves vent system Dry verge HipFast RidgeFast Ridge Roll Dry valley Tile vent Dry verge Cloak verge system Edgemere dry verge Continuous dry verge systems Dry hip Dry hip system Dry valley Plain tile valley GRP slate dry valley system GRP dry valley (low profile) GRP dry valley (high profile) Ventilated dry ridge Ventilated dry ridge Ventilated dry mono ridge Fibre cement ventilated ridges Ventilation terminals Gas vent ridge terminals Ridge vent terminals In-line vents Tile vent terminals * Modern only 6 Ventilation and dry fix system selector

7 Ashmore Ludlow Plus Anglia Double Ludlow EcoLogic Mendip Wessex Modern & Roman Major Ludlow Major Duo Modern * Ventilation and dry fix system selector 7

8 For use with all tiles and slates eaves vent systems 10mm eaves vent system 25mm eaves vent system Key components Universal 10mm eaves vent system (6m pack) Pack comprises of: Eaves rafter roll (6m) Universal 25mm eaves vent system (6m pack) Pack comprises of: Eaves rafter roll (6m) Felt support tray (10 No.) 625 Felt support tray (10 No.) mm strip ventilator (6 No.) 25mm strip ventilator (6 No.) Also available: 1000 Comb filler strip Continuous rafter roll pack (2 No. 6m) 8 Eaves ventilation 325

9 Advantages Can be used with all Marley Eternit and other manufacturers tiles and slates Simple and fast to install Eaves-to-ridge or eaves-to-eaves ventilation pitched roofs Allows clip fixing of tiles at eaves Compresses insulation ensuring airflow Prevents ponding of water Prevents ingress of birds, vermin and insects More literature Sitework Guide for fixing instructions web marleyeternit.co.uk/resources tel Fixing overview Nailing strip ventilator onto fascia board Lay underlay over felt support tray Underlay draped over support tray When using profiled tiles, fix comb filler strip to fascia Eaves ventilation 9

10 dry verge systems For use with large format interlocking tiles including: Double Roman, Edgemere, Duo Edgemere, Ludlow Major, Mendip, Modern, Duo Modern and Wessex interlocking tiles Shown with Mendip interlocking tiles Shown with Edgemere interlocking slates Key components Verge unit left hand 391* right hand 392* Modern mono-ridge end cap left hand 408* right hand 409* Edgemere verge unit left hand 381 right hand 382 Segmental mono-ridge end cap left hand 427* right hand 428* Modern ridge end cap 394* Dry verge refurbishment kit (to fix 24 units) Segmental ridge end cap 395* Dry verge fixing kit (to fix 28 units) Edgemere dry verge fixing kit Edgemere ridge end cap 384 (to fix 28 units) * Suffix with colour code: 01 Grey, 03 Brown, 04 Terracotta Suffix with colour code: 01 Grey, 03 Brown 10 Dry verge systems

11 For Marley Eternit dry fix roofing systems Advantages Strong and durable Weathertight and maintenance free Mechanically fixed Emulates the appearance of traditional verge Simple and fast to install Also suitable for verges without bargeboard Dry verge refurbishment kit allows retro-fit to existing verges More literature Sitework Guide for fixing instructions web marleyeternit.co.uk/resources tel Fixing overview Slide up each unit to interlock Screw fix ridge end cap Mono-ridge end cap with fixing Batten extension unit; part of dry verge refurbishment kit Dry verge systems 11

12 Continuous dry verge systems For use with fibre cement slates, Ashmore interlocking tiles, concrete plain tiles and clay plain tiles Shown with fibre cement slates Key components Fibre cement slates verge trim (3m) MA42206 Universal plain tile dry verge Verge section (3m) Modern ridge end cap, grey Plain tile dry verge fixing kit* * one kit per length of verge Modern mono-ridge end cap left hand right hand Dry verge systems

13 Advantages Strong and durable Weathertight and maintenance free Creates continuous clean verge detail More literature Sitework Guide for fixing instructions web marleyeternit.co.uk/resources tel Fixing overview Nail Slate Verge Trim through flange into battens Slate Verge Trims intersecting at ridge Universal plain tile verge connector units Installed dry verge system 13

14 Cloak verges For use with clay and concrete plain tiles, Mendip, Modern and Double Roman interlocking tiles Shown with concrete plain tiles Shown with Mendip interlocking tiles Key components Mendip cloak verge left hand 245 right hand 246 Mendip half tile 247 Double Roman cloak verge left hand 265 right hand 266 Double Roman half tile 102 Modern cloak verge left hand 370 right hand 371 Modern half tile 372 Concrete plain tile cloak verge left hand 249 right hand 250 Clay plain tile cloak verge left hand right hand 14 Dry verge systems

15 Advantages Strong and durable Weathertight and maintenance free Suitable with or without bargeboard Creates continuous, clean verge Suitable for range of laps Maximum pitch of 55 if top tile mitred Colour matched to main tiles More literature Sitework Guide for fixing instructions web marleyeternit.co.uk/resources tel Fixing overview Completing interlocking profiled tile cloak verge at ridge Maintaining broken bond with half tiles for Modern cloak verge Stop end ridge tile used to finish clay plain tile cloak verge at ridge Concrete block end ridge finishing plain concrete cloak verge tiles Dry verge systems 15

16 For use with all tiles and slates RidgeFast Shown with Edgemere interlocking slates Key components Universal RidgeFast system (6m pack) Pack comprises of: Ridge roll (6m) RidgeFast roll applicator RidgeFast blanking tape (2 x 2m) Ridge batten brackets (10 No.) Ridge unions (13 No.) 16 Dry ridge systems

17 Advantages Simple and fast to install Can be used with all Marley Eternit and other manufacturers tiles and slates Completely dry fixed system Suitable with standard ridge tiles Provides 5mm continuous ventilation along the ridge More literature Sitework Guide for fixing instructions web marleyeternit.co.uk/resources tel Fixing overview Roll out RidgeFast roll Using ridge roll applicator Lay and fix ridges onto roll Secure ridge union Dry ridge systems 17

18 Ventilated dry ridge system For use with all fibre cement slates, concrete tiles and slates Ventilated dry ridge system Ventilated dry mono-ridge system Key components Batten sections (3m) Plain tile High profile Low profile Steep pitch batten sections (45-55 ) (3m) High profile Low profile Segmental ridge junction apex cap 439* Modern ridge union 414* Segmental ridge union 413* Segmental mono-ridge union 423* Modern ridge junction apex cap 440* Segmental mono-ridge end cap left hand 427* right hand 428* For Double Roman, Mendip, Wessex and Anglia For Ashmore, Edgemere range, Modern, Duo Modern, Ludlow Plus, Ludlow Major and fibre cement slates * Suffix with colour code: 01 Grey, 03 Brown, 04 Terracotta 18 Dry ridge systems

19 For Marley Eternit dry fix roofing systems Advantages Simple and fast to install Weather tight and maintenance free Provides 5mm continuous ventilation along the ridge Can be used with all Marley Eternit tiles and slates Fully compatible with dry hip system Can be used up to 55º pitch More literature Sitework Guide for fixing instructions web marleyeternit.co.uk/resources tel Fixing overview Slit underlay between batten sections and clip using H section piece Fixing ridge end cap to dry ridge battens Clip top course interlocking tiles or slates (tiles shown) Fix ridge units and unions Dry ridge systems 19

20 Fibre cement slate ridge with ridge roll For use with fibre cement slates and ridges Advantages Simple and fast to install Maintenance free Can be used for ridges and hips Completely dry fixed system Provides 5mm continuous ventilation along the ridge Shown with fibre cement slates More literature Sitework Guide for fixing instructions web marleyeternit.co.uk/resources tel Key components Fixing overview Universal ridge roll Fibre cement ventilated dry ridges Duo pitch ridge Stop end for duo pitch ridge Roll top ridge Stop end for roll top ridge Ridge roll with ridges 20 Dry ridge systems

21 Top abutment ventilation system For use with concrete tiles and slates, and fibre cement slates Advantages Provides ventilation for lean-to roofs Completely dry fixed Provides continuous 5mm ventilation along abutment Provides eaves-to-abutment ventilation when used with universal eaves system Shown with Mendip interlocking tiles More literature Sitework Guide for fixing instructions web marleyeternit.co.uk/resources tel Key components Fixing overview Batten sections (3m) Plain tile High profile Low profile Steep pitch batten sections (45-55 ) (3m) High profile Low profile Lead support strip Insertion of profiled tiles into batten section Double lap slates fixing kit For Double Roman, Mendip, Wessex and Anglia For Ashmore, Edgemere range, Modern, Duo Modern, Ludlow Plus, Ludlow Major and fibre cement slates Finish by dressing lead onto lead support strips Abutment systems 21

22 For use with all tiles and slates HipFast Shown with Mendip interlocking tiles Key components Universal HipFast system (6m pack) Pack comprises of: Hip roll (6m) * Sold separately Tapered ridge filler (2 No.) 1m length hip support trays (9 No.)* Hip batten brackets (6 No.) Ridge unions (13 No.) 22 Dry hip systems

23 Advantages Simple and fast to install Can be used with all Marley Eternit and other manufacturers tiles and slates Completely dry fixed system Suitable for standard hip tiles Provides 5mm continuous ventilation More literature Sitework Guide for fixing instructions web marleyeternit.co.uk/resources tel Fixing overview Fixing hip batten brackets Fixing hip batten Roll out HipFast roll Fixing hip unions Dry hip systems 23

24 Dry hip system For use with all concrete tiles and interlocking slates Shown with Mendip interlocking tiles Key components Dry hip batten section (low profile) Modern ridge union 4140* Dry hip batten section (high profile) Dry hip batten section fixing kit (1 kit per 3 metre batten section) Low profile High profile Modern stop end hip tile 292 Modern hip apex cap * * * Third round stop end hip tile 292 Third round ridge union 4140* Third round hip apex cap * * * * Suffix with colour code: 1 Grey, 3 Brown, 4 Terracotta 24 Dry hip systems

25 For Marley Eternit dry fix roofing systems Advantages Simple fast installation Weathertight and maintenance free Can be used up to 55 pitch Can be used with all Marley Eternit tiles and slates Fully compatible with ventilated dry ridge system More literature Sitework Guide for fixing instructions web marleyeternit.co.uk/resources tel Fixing overview Locate hip batten section between cut tiles Insert closed cell foam rubber slip at hip/ridge junction Locate block end hip tile and assembly Secure apex junction cap with hip/ridge unions Dry hip systems 25

26 GRP dry valley For use with all concrete plain tiles, interlocking tiles and slates High profile, shown with Mendip interlocking tiles Key components GRP dry valley trough compatibility Tile High profile Low profile GRP valley (low profile) Ashmore Anglia Double Roman GRP valley (high profile) Edgemere/ Duo Edgemere Ludlow Major Ludlow Plus Mendip Modern/ Duo Modern Wessex Plain 26 Dry valley systems

27 CERTIFICATE No 93/2909 For Marley Eternit GRP valley trough flashings Advantages Dry fix, mortar-free system Durable GRP technology Simple and fast installation Can accommodate up to 20 pitch variance either side of valley Performs on pitches up to 60 Gives the appearance of a close cut roof More literature Sitework Guide for fixing instructions web marleyeternit.co.uk/resources tel Fixing overview Valley board construction Placement and fixing of valley trough Tiles or slates cut to rake of valley Dry valley systems 27

28 GRP valley systems For use with fibre cement slates CERTIFICATE No 93/2909 For Marley Eternit GRP valley trough flashings Advantages Dry fix, mortar free system Durable GRP technology Simple and fast installation Accommodates up to 15 pitch variance either side of the valley Shown with fibre cement slates More literature Sitework Guide for fixing instructions web marleyeternit.co.uk/resources tel Key component Fixing overview GRP slate dry valley trough Clipped, raking cut interlocking slates laid with GRP valley trough 28 Dry valley systems

29 tile vent terminal For use with large format interlocking tiles and slates Advantages Ideal for natural, mechanical or soil pipe ventilation Weatherproof, tough and durable Suitable for large format and most 15 x 9 interlocking tiles 15,000mm 2 free area of ventilation Choice of 3 colours Shown with Mendip interlocking tiles More literature Sitework Guide for fixing instructions web marleyeternit.co.uk/resources tel Key components Fixing overview Universal tile vent terminal Grey Brown Terracotta Flexible pipe ID 110mm (sold separately) Ensuring good seal between Universal tile vent terminal and tiles Pressure resistance values Pa (litres/sec airflow) ,000mm 2 free area Finishing tiling and creating a weatherproof seal Roof slope systems 29

30 Contour in-line vents For use with concrete and clay plain tiles and concrete interlocking tiles and slates Advantages Contoured to match tile profile Almost invisible from ground level Ideal for mid slope roof ventilation Internal spigot for connection to mechanical extract or soil pipe ventilation Shown with Mendip interlocking tiles More literature Sitework Guide for fixing instructions web marleyeternit.co.uk/resources tel Key components Plain contour tile vent 455* terminal Anglia contour tile vent 460* terminal Edgemere contour tile vent 465* terminal Wessex contour tile vent 459* terminal Mendip contour tile vent 452* terminal Ludlow Major contour tile 456* vent terminal Modern contour tile vent 451* terminal Ludlow Plus contour tile 457* vent terminal * Available in grey and brown 30 Roof slope systems

31 For Marley Eternit contour tile vent terminals Pressure resistance values Tile Free area of Pa (litres/sec airflow) ventilation (mm 2 ) Anglia 15, Ashmore 10, Double Roman 13, Edgemere 10, Ludlow Major 11, Ludlow Plus 15, Mendip 14, Modern 10, Plain 10, Wessex 12, Double Roman contour tile 453* vent terminal Fixing overview Ashmore contour tile vent 450 terminal Flexible pipe ID 110mm (sold separately) Make aperture in underlay using template * Available in grey and brown Secure soaker tray Roof slope systems 31

32 Clay in-line vent For use with clay plain tiles Advantages Real clay tile slips provide visual integration on roof slope 7,500mm 2 free area of ventilation Ideal for natural, mechanical or soil pipe ventilation Shown with clay plain tiles More literature Sitework Guide for fixing instructions web marleyeternit.co.uk/resources tel Key components Fixing overview Clay in-line tile vent In-line tile vent adaptor Mark throat position and cut underlay Flexible pipe ID 110mm (sold separately) 340mm Pressure resistance values Pa (litres/sec airflow) ,500mm 2 free area Position and fix in-line vent unit 32 Roof slope systems

33 Fibre cement in-line vent For use with fibre cement slates Advantages Provides visual integration with roof slope Ideal for natural, mechanical or soil pipe ventilation 10,000mm 2 free area of ventilation Shown with fibre cement slates More literature Sitework Guide for fixing instructions web marleyeternit.co.uk/resources tel Key components In-line slate vent Fixing overview Additional support batten In-line fibre cement/natural PVCu slate ventilator Secure additional support batten Flexible pipe ID 110mm (sold separately) 280mm cut between battens Pressure resistance values Pa (litres/sec airflow) ,000mm 2 free area no. 5mm drilled holes Secure underlay support to support batten Determine position of ventilator Roof slope systems 33

34 Tile ventilation terminals For use with large format concrete interlocking tiles and Ashmore concrete interlocking tiles Advantages Wide range of colours and finishes Ideal for natural, mechanical or soil pipe ventilation Shown with Mendip interlocking tiles More literature Sitework Guide for fixing instructions web marleyeternit.co.uk/resources tel Key components Edgemere tile vent terminal 259 Double Roman tile vent 298 terminal Ludlow Major tile vent 297 terminal Wessex tile vent terminal 294 Mendip tile vent terminal 294 Flexible pipe ID 110mm (sold separately) Modern/Duo Modern 295 tile vent terminal Ashmore ventilation 263 roof tile 34 Roof slope systems

35 Pressure resistance values Tile Free area (mm 2 ) Pa (litres/sec airflow) Ashmore 4,500 Double Roman 7, Edgemere 7, Ludlow Major 7, Mendip 7, Modern 7, Wessex 6, Fixing overview Make aperture in underlay using template Secure soaker tray Roof slope systems 35

36 Ridge vent terminals Systems available for concrete tiles and fibre cement slates Shown with Mendip interlocking tiles Key components For concrete tiles and slates Ridge vent terminal 198 Also available: Gas vent ridge terminals for concrete tiles and slates Gas vent ridge terminal 256 (with extension piece) Plumbers accessory pack (for ridge vent terminals only) Spare gasket set For fibre cement slates In-line ridge ventilator plus extension sleeve (900mm) 20, 25, 30, 35, 40, 45 In-line ridge ventilator stepped adaptor * Made to order Gas vent ridge flue terminal for condensing boilers Segmental 254* Modern 255* Flexible pipe Ridge vent terminals

37 Advantages Suitable for mechanical or passive stack ventilation Compatible with our range of ventilated dry ridge systems Simple and fast installation More literature Sitework Guide for fixing instructions web marleyeternit.co.uk/resources tel Fixing overview Installation of clay ridge vent terminal (with flexible pipe) Ridge vent terminals 37

38 Ventilation requirements for cold roofs Key to illustrations Warm roof/building areas Cold roof areas Low Resistance underlay High Resistance underlay Sarking Normal ceiling A ceiling where no attempt has been made to seal all gaps or penetrations (e.g. light drops, pipes etc.) Well sealed ceiling The design avoids construction gaps, especially at the wall ceiling junction with dry lining construction and holes in the ceiling. No access door or hatch should be located in rooms where large amounts of moisture are produced, including kitchens or bathrooms. The ceiling is sealed to the external walls to limit any leakage through cracks. The head of all cavities in the external walls, party walls and partition walls is sealed to prevent transfer of warm moist air into the loft. Roofs with a well-sealed ceiling Bituminous felts and vapour impermeable underlays (high resistance) The ventilation requirements for cold roofs with vapour impermeable underlays and 'well-sealed ceilings' are the same as those without. Installing a 'well-sealed ceiling' will make the roof more energy efficient because airtightness will have prevented heat loss through convection. Heat loss due to low speed air currents over the cold side of the insulation (caused by ventilation) is negligible. Vapour permeable underlays (low resistance) The installation and maintenance of a 'well-sealed ceiling' with a vapour permeable underlay can reduce the ventilation requirements. However, where a close fitting roof covering is used, the batten space should be ventilated in accordance with BS 5250: 2011 using counterbattens. 10,000 10,000 mm 2 /m Well-sealed ceiling 3,000 3,000 mm 2 /m Well-sealed ceiling Roof spans under 10m (pitches under 35 ) 5,000 mm 2 /m Roof spans under 10m (pitches of ) 5,000 mm 2 /m 10,000 mm 2 /m 10,000 mm 2 /m 3,000 mm /m 3,000 mm /m Normal ceiling Well-sealed ceiling Roof spans over 10m (or pitches over 35 ) Roof spans over 10m (or pitches over 35 ) 38 Condensation and guidance

39 Roofs with a normal ceiling Bituminous felts and vapour impermeable underlays (high resistance) Ventilation of the loft space under a traditional bituminous felt or non-vapour permeable underlay has proven to be an effective and robust solution when used with suitable high and low level ventilation. 10,000 10,000 mm 2 /m Vapour permeable underlays (low resistance) The use of a low resistance underlay can reduce the requirement for ventilating the roof space. On fully boarded roofs, i.e. sarking, low resistance underlays should be treated as impermeable and the roof space below ventilated in accordance with the high resistance underlay requirements described above. Where a close-fitting roof covering has been used, the batten spacing should be ventilated in accordance with BS 5250: 2011 using counterbattens. Normal ceiling Roof spans under 10m (pitches under 35 ) 7,000 7,000 5,000 mm 2 /m Normal ceiling Roof spans under 10m (pitches under 35 ) 10,000 mm 2 /m 10,000 mm 2 /m 5,000 Normal ceiling Roof spans over 10m (or pitches over 35 ) 7,000 7,000 Normal ceiling Fully breathable underlays The British Standard mainly distinguishes between two types of underlay: high resistance (HR) impermeable and low resistance (LR) vapour permeable. However, there are some manufacturers of low resistance underlays that claim their products are fully breathable, negating the requirement for ventilation as set out in the British Standard. There are a number of factors to consider before using any type of low resistance underlay, including: 1. How well-sealed the ceiling is 2. Whether a close-fitting roof covering is being used 3. Obstructions in the roof space In all circumstances, Marley Eternit recommend the use of additional ventilation when using any type of low resistance underlay. This can be achieved through the use of ventilated eaves and ventilated ridge systems. Close fitting coverings When specifying a close fitting covering which is relatively airtight (such as fibre cement slates), there is a risk of interstitial condensation forming on the underside of the underlay and the external covering. To avoid this risk, the batten space should be ventilated in accordance with BS 5250:2011 using counterbattens. 10,000 Roof spans over 10m (or pitches over 35 ) Normal ceiling 10,000 For sarking applications: Roof spans under 10m (pitches under 35 ) 10,000 5,000 Normal ceiling 10,000 For sarking applications: Roof spans over 10m (or pitches over 35 ) Condensation and guidance 39

40 Ventilation requirements for warm roofs Warm pitched roof with HR underlay In roofs with an HR underlay, whatever form of external covering or ceiling is provided, there is a risk of interstitial condensation forming on the underside of the HR underlay. To avoid that risk, an AVCL (air vapour control layer) should be provided on the warm side of the insulation and ventilated voids should be formed between the underside of the underlay and the insulation. Each void should be at least 25mm deep and vented at both high and low level. Roofs with an AVCL Bituminous felts and vapour impermeable underlays (high resistance) The ventilation requirements for cold roofs with vapour impermeable underlays and 'well-sealed ceilings' are the same as those without. Installing a 'well-sealed ceiling' will make the roof more energy efficient because airtightness will have prevented heat loss through convection. Heat loss due to low speed air currents over the cold side of the insulation (caused by ventilation) is negligible. Warm pitched roof with LR underlay In warm pitched roofs with LR underlay, an AVCL (air vapour control layer) should be provided at the ceiling line. If the external covering is sufficiently permeable, it will allow vapour to be released and no ventilation of the batten space is recommended. 25,000 50mm 5,000 Cold HR underlay 5,000 Cold 25,000 If it is not practicable to provide an AVCL, there might be some risk of interstitial condensation forming on the underside of the underlay. To avoid the risk, ventilated voids should be provided. Key to illustrations Low Resistance underlay High Resistance underlay Traditional underlay and AVCL (10-75 pitches) Vapour permeable underlays (low resistance) Where an AVCL has been installed, the harmful effects caused by condensation can be controlled by the use of a vapour permeable underlay without ventilation. The vapour permeable underlay may be laid fully supported on the insulation or draped unsupported. An AVCL is essential on the warm side of the insulation. If there is any doubt about the ability to provide and maintain an effectively sealed AVCL, then ventilation should be provided as if the underlay were impermeable. LR underlay LR underlay with AVCL 40 Condensation and guidance

41 Roofs with a close-fitting roof covering For warm roofs with a close-fitting roof covering, ventilation will be required either above or below the underlay, dependent on the underlay type. 50mm 25,000 5,000 Cold 5,000 LR underlay 5,000 Cold Ventilation void above underlay 5,000 25,000 5,000 25,000 Fully breathable underlays The British Standard mainly distinguishes between two types of underlay: high resistance (HR) impermeable and low resistance (LR) vapour permeable. However, there are some manufacturers of low resistance underlays that claim their products are fully breathable, negating the requirement for ventilation as set out in the British Standard. There are a number of factors to consider before using any type of low resistance underlay, including: 1. How well-sealed the ceiling is 2. Whether a close-fitting roof covering is being used 3. Obstructions in the roof space In all circumstances, Marley Eternit recommend the use of additional ventilation when using any type of low resistance underlay. This can be achieved through the use of ventilated eaves and ventilated ridge systems. Close fitting coverings When specifying a close fitting covering which is relatively airtight (such as fibre cement slates), there is a risk of interstitial condensation forming on the underside of the underlay and the external covering. To avoid this risk, the batten space should be ventilated in accordance with BS 5250:2011 using counterbattens. 25,000 50mm Cold HR underlay Cold 25,000 Ventilation void below underlay Condensation and guidance 41

42 Technical toolkit tools and support that make design and specification as straightforward as possible CAD details Access to over 2,000 CAD drawings illustrating how specific tile and slate details can be formed. System selector Easy-to-use and comprehensive tiles and fittings system finder delivering results from choice of pitch, material or specific tile type. marleyeternit.co.uk/cad marleyeternit.co.uk/selector Tilefix Tool to create fixing specifications based on the geographical location and building dimensions of specific roofing projects. marleyeternit.co.uk/tilefix NBS Specs A tool to produce instant NBS clauses that meet the recommendations of British Standards and s of Practice. marleyeternit.co.uk/specrite Estimator Tool designed to create a complete bill of materials for your roofing project, based on a wide range of roof shapes. marleyeternit.co.uk/estimator BIM BIM Space is a set of free to download Building Information Modelling (BIM) objects that provide a standard range of build ups for our fibre cement roof slates and facades. marleyeternit.co.uk/bim This publication is based on the latest information available at the time of printing. Due to product changes, improvements and other factors, Marley Eternit reserves the right to change or withdraw information contained herein without prior notice. The information contained herein is based on Marley Eternit s current recommendations intended for general roof applications, but where nonstandard situations occur or where abnormal site exposure conditions apply, users must satisfy themselves as to the suitability of the recommendations given. Furthermore, the advice given in isolation should not be taken as providing any guarantee of the performance or suitability of the product for specific applications. For specific applications users should refer to the relevant Standards and s of Practice for guidance or contact the Technical Advisory Service for advice. All Marley Eternit Dry Fix products will have a life comparable with other components of the roofing system. Components manufactured from PVCu that are subjected to long term exposure to the weather will suffer UV degradation; this may cause fading and a reduction in impact strength although the performance of the product will remain unaffected. Marley Eternit s employees or agents are not authorised to make any representations, or give any advice or recommendations, concerning any goods or services unless confirmed by Marley Eternit in writing. 42 Services

43 Resources Technical Advice Our Technical Advisory Service is staffed by a qualified team with specialist knowledge. Tel info@marleyeternit.co.uk Customer Services Knowledgeable and friendly staff are available to offer quotations, expert advice, deal with orders and all other enquiries. Tel info@marleyeternit.co.uk Samples Samples of fibre cement slates, clay and concrete tiles are available on request. Tel marleyeternit.co.uk/samples Literature and CPDs All product and technical literature can be requested or downloaded. CPDs are also available for more information or to make a booking, visit: marleyeternit.co.uk/resources Stockist information To find details for stockists of Marley Eternit products, visit: Fixing instructions Comprehensive sitework, fixing and installation guidance for all Marley Eternit ranges and project types. marleyeternit.co.uk/stockists marleyeternit.co.uk/resources Training centre We have a purpose-built training centre where we are able to impart our expertise through a range of practical and classroom courses. To find out more about our courses, visit: marleyeternit.co.uk/training Sales support Our Area Sales Managers have in depth knowledge of your local area. They are available to visit your site to carry out a roof survey, and to offer specific solutions for both new build and refurb projects. marleyeternit.co.uk/localcontacts Services 43

44 Customer Services T F E info@marleyeternit.co.uk Marley Eternit Limited, Lichfield Road, Branston, Burton on Trent, DE14 3HD