Fibre Cement Roofing

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Fibre Cement Roof

 

Fibre Cement Roofing has proved to be the most durable roofing material at the most affordable price. Millions of fibre cement roofs in the world have witnessed the test of time successfully.

A material with superior characteristics

  • Noise attenuation
    Reduction of the noise caused by driving rain
  • No corrosion, no rust
    Resistant to the high salinity of coastal area
  • Can be painted and repainted
    Dirt from surface should be removed before repaint works
  • Fire resistant
    Fibre cement sheets are incombustible and don’t generate smoke
  • Chemical resistant
    Highly resistant to many industrial chemical vapors in the industry and livestock areas

 

 

Technical Data & Accessories

 

 

Profiled Sheeting

Profiled Sheeting is manufactured from a carefully formulated mix of Portland cement and water, reinforced with a combination of both natural and synthetic fibres.

The longevity of this formulation means that profiled sheeting has a life expectancy of at least 50 years.

Advantages of Profiled Sheeting

  • Can achieve A+ or A ratings in Green Guide
  • Only UK manufacturer of fibre cement
  • Highly cost effective weatherproofing
  • Low maintenance
  • No rust, rot or corrosion
  • Resistant to chemical attack
  • Vapour permeability reduces condensation
  • Excellent noise and thermal insulation
  • Quick and easy to install and fix
  • Wide product and colour range

Profile 6

A high strength fibre cement sheet reinforcement providing maximum impact strength and durability. Profile 6 has a very broad appeal for roofs of 5° pitch and over or vertical profiled sheeting.

Profile 3

Profile 3 is easy to handle and is suitable for small structures in the agricultural, industrial and domestic sectors, such as garages, general purpose sheds and smaller buildings.

Farmscape Anthracite

As Profile 6 but designed to reduce the visual impact of buildings on the landscape by applying a subtle surface pigmentation to the top face of the sheet.

Translucent sheets

A wide range of GRP translucent sheets that meet the requirements of ACR(M)001:2005, and have a fire rating of SAB Class 3.

Ventilation

A wide and versatile range of ventilation systems for commercial agricultural and industrial applications.

Housing

 

Profiled sheeting combines well with other modern building materials to give unique visual character to walls or roofs for many residential products.

Industrial

 

Fibre cement has high resistance to aggressive environments and excellent performance characteristics ideal for industrial applications.

Commercial

 

From distribution centres to business parks, profiled sheeting can be used to create unique building skins with visual impact and maximum durability.

Adopting best practice

100% of all products used in construction should be responsibly sourced by 2015.

The issues of global warming, climate change and their effect on our environment are becoming ever more important throughout the construction industry.

At Le Fong we are at the forefront of helping our customers and suppliers to put environmental best practice at the top of their agenda.

BES 6001: Responsible sourcing

Le Fong is assessed to BES 6001

As the UK’s leading manufacturer and supplier of roofing and facades products, Le Fong is committed to sourcing its raw materials and managing its supply chain in a responsible and sustainable manner and has been accredited BES 6001 ‘Framework Standard for the Responsible Sourcing of Construction Products’. This accreditation means:

  • We are responsible for our supply chain, both who we choose and their actions.
  • We are responsible for raw materials we purchase.
  • We are responsible for the services we procure.
  • We can help architects, designers, developers and builders achieve a high level of points when building sustainably, using either BREEAM, The Code for Sustainable Homes or Eco Homes schemes. A ‘good’ BES 6001 rating can be worth 2 points in the ‘materials’ category

Best practice

Our commitment to best practice in the sustainability of our products, responsible sourcing of the materials used in our products, and the environmental impact of our operations is conducted in the following key areas:

  • Health & Safety
  • Environment
  • Quality
  • Corporate Social Responsibility

Le Fong operates certified Quality, Health and Safety and Environmental management systems, to the internationally recognised ISO 9001, ISO 14001 and OHSAS 18001 standards at all of its manufacturing locations.

In order to maintain its certification to ISO 14001, Le Fong has to minimise the harmful effects on the environment caused by its activities and also to achieve continual improvement with its environmental performance.

The quality of Le Fongs products and services remains at the top of the agenda in the overall company business strategy, and the maintenance of a quality management system operating to ISO 9001 ensures that the manufacturing, sales and distribution processes are continually monitored and improved to meet the changing needs of our customers.

Le Fong maintains a Health and Safety management system operating to OHS 18001 covering all aspects of the business, including manufacturing, materials handling, administration, engineering, external sales and interaction with customers or contractors either at our sites or on their premises.

Sustainability is that which meets the needs of the present without compromising the ability of future generations to meet their own needs…

Manufacture and carbon reduction

Manufacture of fibre cement

This is a low energy process using readily available locally sourced or sustainable resources which are natural and abundant. Production waste is recycled into the production process.

Cement can often be a main contributor to the equivalent carbon dioxide emission during the manufacture of fibre cement products, so we continually develop formulations that replace cement by raw materials of low carbon equivalent.

As the only UK manufacturer of fibre cement slates and profiled sheeting, we can guarantee fewer delivery-miles for these products compared to imported products.

Water recycling

We’re saving around 2,000m3 of water each year through recycling water recovered from manufacturing processes.

Reducing waste

Wherever possible, all our sites recycle waste rather than send it to landfill. We’ve installed waste-to-heat power plants at two of our factories, converting all sorts of waste – from cement bags to irreparably damaged timber pallets – to heat.

Our Keele plant recycles all green waste and re-uses waste water. as well as having its own natural water sources (boreholes).

We have various schemes in place where we re-use all waste concrete material within our products as well as using locally imported re-usable material from other manufacturers. The level of recycled material we use currently in the production of concrete tiles is 20%.

Energy usage monitoring and saving

Many organisations simply rely on information from a single meter to gauge energy consumption.

We’ve introduced sub-meters and mobile metering that enable us to identify precisely how much energy is used by different facilities on our sites. This means that energy usage can be managed in a much more sophisticated and informed way.

Electricity, gas, oil and water consumption is measured and compared across our factories. The monthly data helps us to identify where improvements can be made. At one site we periodically use methane produced by a local landfill to generate the heat which cures tiles and heats the workplace.

Reducing our carbon footprint

Le Fong is developing its sustainable Carbon Management Programme aimed at reducing carbon emissions and improving its ‘carbon footprint’. We have set ourselves a target to reduce the carbon emissions from manufacturing processes over six years from an index of 100 (based on 2006 data) to an index of 75.

The monitoring of Le Fong’s carbon reduction target is overseen by an internal Energy Action Group, which uses a sophisticated computer based energy management system which monitors energy usage and CO2 generated, against tonnage of material produced.

Lower embodied energy products

A product manufactured using a process which uses less energy and less primary raw materials will generally have a much lower embodied energy (the energy used to acquire, process, and manufacture the product, including any transportation related to these activities). These products will be more sustainable and will help specifiers to attain higher ratings against sustainability requirements set out in current legislation.

Assessing the sustainability of fibre cement profiled sheeting

When used in A+ rated constructions, fibre cement profiled sheeting can achieve 3 credits in the materials category of the Code for Sustainable Homes and can help achieve ‘Good’ or ‘Excellent’ ratings for BREEAM for non-residential buildings.

BRE Green Guide on-line

Our range of fibre cement profiled sheeting is UK manufactured and as such, is the only fibre cement profiled sheeting able to achieve A+ or A ratings in the BRE Green Guide to Specification.

The BRE ‘Green Guide’ online www.thegreenguide.org.uk contains a listing of building materials and components which are assessed in terms of their environmental impact across their entire life cycle – from ‘cradle to grave’, within comparable specifications.

The Green Guide contains more than 1200 specifications used in various types of building which examine the relative environmental impacts of the construction materials commonly used in six different generic types of building covering six sectors.

Materials and components are arranged on a ‘building element’ basis so that designers and specifiers can compare and select comparable systems or materials that may be used in, say, roofs, walls, floors etc.

Across these building element categories, the Guide provides an extensive, but not complete, catalogue of building specifications covering most common building materials.

This data is set out as an A+ to E ranking system, where A+ represents the best environmental performance/least environmental impact and E the worst environmental performance/most environmental impact. BRE has provided a summary environmental rating – ‘The Green Guide’ rating – which is a measure of overall environmental impacts covering the construction specifications (i.e. they are not manufacturer specific).

Ratings tables

For each element, the ‘Green Guide’ ratings are displayed alphabetically in tables. Depending on the number of specifications, the element group may have been divided into sub-categories. The ratings are based on the range for the whole element group, not the sub-categories.

The table below contains information taken from ‘The Green Guide’ and details some of the specifications covered in the rainscreen profiled sheeting section.

 

Design considerations

Recommended design procedure

Designers are advised to consider the following steps when commencing a design incorporating Le Fong profiled sheeting.

This information is provided for guidance only and designers should ensure that they make all the necessary calculations and take into account all aspects of the specific project design and location.

In addition to this Profiled Sheeting manual, reference should also be made to the following standards:

BS8219 Installation of sheet roof and wall coverings – Profiled fibre cement – Code of practice.

BS 5427: Part 1, Code of Practice for The use of profiled sheet for roof and wall cladding on buildings Part 1. Design.

BS 5502 Buildings and structures for agriculture, parts 20, 21 and 22.

 

Step 1: Legislation and planning

Guidance on legislation is given on pages 26-27. Planning permission may be necessary and is dependent on Local Authority policy and control.

Step 2: Wind and snow loadings

Calculate the wind suction loading in accordance with BS EN 1991 Eurocode 1 – Actions on structures – Part 1-4: General actions – Wind actions.

Calculate the snow loadings in accordance with BS EN 1991 Eurocode 1 – Actions on structures – Part 1-3: General actions – Snow loads.

Step 3: Exposure, wind and rai

Establish the exposure zone of the site by reference to the map on page 28. This divides the UK into 2 categories of exposure to driving rain and is based on the table in BS 8219: 2001 + A1: 2013.

Step 4: Assess performance against regulatory requirements

Profiled sheeting performance criteria will vary according to design, building function etc., Further guidance is shown on the following pages: ‘Sound insulation’, page 46, ‘Fire’, page 46, ‘Condensation control’, page 47, and ‘Thermal’, page 47.

Step 5: Profiled sheeting selection

The choice of profiled sheeting is a combination of planning, aesthetic and performance criteria. The key factors are shape, size, colour, texture, material and sustainability, see pages 36-47.

Step 6: Framework and support rail

Determine design of profiled sheeting and configuration of support rails with structural engineer and framework manufacturer.

Ensure that the structure is adequate for the total weight of the profiled sheeting as installed and for the calculated wind loading and any other relevant loading criteria. Weights of panels are shown on the appropriate product pages.

Step 7: Fixing method

Select the fasteners to suit the profiled sheet and type of purlin being used.

Step 8: Fittings and accessories

Select the accessories to suit the particular details of the building by referring to Design Detailing pages 48-69.

Step 9: Produce project specific specifications and drawing

Legislation, guidance and reference

Before contemplating any profiled sheeting project, the designer and contractor must be aware of the current legislation, the design requirements and standards that govern and influence the style, parameters, performance, products and construction of the project. The following section summarises many of the relevant documents, but is by no means exhaustive.

Scottish Technical Handbooks

The sections referred to above are contained in the two Scottish technical handbooks, one covering domestic construction, the other non-domestic.

Other guidance:

  • ACR(M)001:2014. Test for Non-Fragility of Large Element Roofing Assemblies (Fifth Edition)
  • ACR(CP)001:2007. Recommended Practice for Work on Profile Sheeted Roofs.
  • Health and Safety Executive. HSG33 Health and safety in roof work.

Health and safety

To ensure safe working practices during construction, the designer should consider relevant safety regulations. These include the Construction (Design and Management) Regulations and the Health and Safety Executive’s approved code of practice for management of health and safety at work.

Certain advisory bodies such as the National House Building Council (NHBC), Loss Prevention Council (LPC), Building Research Establishment Ltd (BRE) and Timber Research and Development Association (TRADA) also produce recommendations and guidance on construction which should be considered.

Wind loadings and lap treatment

Introduction

When specifying profiled sheeting, the windloading and exposure of the site is critical to ensuring the optimal sealing and fixing of the sheets.

As the sheets are fixed through oversize holes in the crest corrugations, they cannot be used in a stressed skin construction, and cannot be assumed to provide lateral restraint to the top flange of a purlin.

When designing the steel structure the maximum purlin deflection under total serviceability loads should not exceed the formula: purlin span/220.

Exposure

Determine the expected degree of exposure by examining the map, below left.

Where buildings stand above their surroundings, or are situated in open country with no windbreaks within about 1km (including sites on or near the sea coast or hilltop sites which are above the general level of trees, etc.), they must be considered subject to severe exposure. Refer to BRE Digest 127 ‘An Index to Exposure to Driving Rain’, or the BSI Draft for Development DD93, taking account of the recommendations regarding localised effects, on high buildings, on buildings of any height, on hill slopes or hill tops, in coastal districts, or in other areas where higher exposure gradings are likely.

Wind loading should be calculated in accordance with BS EN 1991 Eurocode 1: Actions on structures – Part 1-4: General actions – Wind actions.

Centres of support

For Profile 6: Purlins at 1375mm c/c for wind suctions of 1.89kN/m². Rails at 1825mm c/c for loadings up to 1.40kN/m².

For Profile 3: Purlins at 925mm c/c for loadings up to 1.79kN/m² (multiple span) or 1.49kN/m² (single span). Rails at 1225mm centres for loadings up to 1.02kN/m² (multiple span) or 0.64kN/m² (single span).

Lap and seal

Establish the requirement for lapping and sealing by reference to the map of the UK left and the tables below.

Sheltered to moderate sites

Less than 56.5 l/m2 of wind-driven rain per spell.

Lap treatments

Lap – This describes how much one sheet overlaps another at each end (end lap) and each side (side lap).

Pitch – This describes the degree to which the roof slopes.

The table above is based upon BS 8219 and applies to roof slopes not exceeding 32m.

(Consult the Le Fong Technical Department for advice on roof slopes that exceed 32m.)

Minimum roof pitches

The minimum pitch for Profile 6 sheets is 5° and 10° for Profile 3.

Where slopes are between 5° and 10°, the maximum slope length should be 15m, with double sealed end laps and single sealed side laps.

On roofs over 10° pitch, where parapets might allow snow build-up, 300mm double sealed end laps and single sealed side laps are recommended. On such roofs, workmanship as regards positioning and placing of butyl strips is more critical and greater care is necessary with lap sealing.

Sealing

Sealants*

It is important to select a good quality sealant. Inferior sealants can lead to cracking, chalking and failure in use. For best results, BS 8219 recommends a pre-formed 8mm diameter mastic ribbon of butyl or a polyisobutylene-based material, which has a rubbery, tacky consistency, and which will adhere to both surfaces when sheets are overlapped.

* Sealants are available from the following companies: Fixfast (tel. 0845 4507483), Woodall Fastening Systems (tel. 01384 263900), Hodgson Sealants (tel. 01482 868321), Premier Sealant Systems (tel. 01724 864100).

Side laps

When sealed side laps are required, butyl strips should be positioned as shown in Fig.1 below.

End laps

The minimum end lap for Profiles 6 and 3 is 150mm, fixed as shown in Fig.2 below.

Where double sealing is necessary, with a 300mm end lap, the second butyl strip should be positioned 100 to 200mm below the fixing, as shown in Fig.3 below.

Fittings

The requirement for sealing laps also applies to any fibre cement fittings that are used together with the sheets.

Setting out the roof

Laying the sheets

Roof sheeting should commence from one end of the building at eaves level, rising in vertical tiers, one sheet wide, from eaves to ridge. Where cranked crown sheets are used, it is especially important that the slopes are accurately aligned with each other. Vertical sheeting should also be fixed in tiers, one sheet wide, from the lowest level of the profiled sheeting.

The end laps of each row of sheets should form a continuous straight line from gable to gable and must not be staggered. Similarly, the side laps should be aligned from eaves to ridge.

Checking the structure

Before sheeting is commenced, the structure should be checked to ensure that all purlins and rails are in a true plane, correctly spaced and securely fixed and adequately restrained.

Setting out plan

Typical double slope roof is shown below with two piece adjustable close fitting ridge and Profile 6 sheets.

Note: For typical mitring detail with 150mm end lap, see following page.

Mitring

General guidance

To avoid four thicknesses of sheeting at the junctions of side and end laps, it is necessary for two of the sheets at each junction to be mitred at the corners so that they lie in the same plane.

Mitres on Profile 6 and 3 sheets should be cut from a point 150mm up the vertical edge from the corner (or the amount of the end lap) to a point 70mm (131.2mm for Profile 3) along the horizontal edge, i.e., the width of the side lap by the length of the end lap.

Ideally, the gap between mitres should be a minimum of 3mm to a maximum of 6mm. Box mitres should be avoided. The mitred joint is covered top and bottom by the other two sheets, and is thus weatherproof and unseen (see typical mitring details below.)

Mitring layouts

The procedure for mitring the sheets for single and double slope roofs is indicated on the mitre plans below (Figs.1-3).

On double slope roofs with two piece adjustable close fitting ridges or cranked crown ridges, one slope must be laid left to right and the other right to left.

When cranked crown ridge pieces are used, both top courses of roofing sheets and the cranked crowns should be mitred.

When using two piece ridges, the top courses of sheets and the ridges should not be mitred.

Note: All mass-produced building products are allowed certain dimensional tolerances. This applies to both profiled fibre cement sheets and steelwork. Because of these permitted variations in dimensions, regular checks should be carried out on measurements at mitres, and adjustments made as and when necessary.

Fixing

General guidance

All sheets must be fixed in accordance with the recommendations of BS 8219.

Profiled sheeting should always be fixed with 2 fasteners per sheet per purlin.

The selection of the correct sheet fastener is extremely important. The integrity of the roof covering, type of purlin or rail system, and weatherproofing with washers and caps all must be considered to avoid premature failure, corrosion or a leaking roof.

Topfix fasteners

Self-drilling, self-tapping ‘topfix’ fasteners are generally used to fix Profile 6 sheets to the purlins (Fig. 4). These fasteners drill through the Profile 6 sheet, creating a 2mm oversize hole and self tap into the purlin. It is important that the fasteners are installed using the correct power tools, which should have an adjustable depth setting device to ensure the washers are seated correctly. The fasteners typically have different drill points to suit the different purlin types:

When following the recommendations of the fastener manufacturers, please give particular regard to minimum purlin thickness and maximum roof pitch.

Traditional fasteners

In certain circumstances it may be preferable to use traditional fasteners such as hook bolts, crook bolts and drive screws. There are, however, additional health and safety implications to consider when using these fixings.

The fasteners are generally 8mm diameter for Profile 6 and are fixed through 10mm diameter pre-drilled holes in the sheet. For hook and crook bolts, the fixing should be positioned 4mm upslope from the back leg of the purlin. Drive screws should be located centrally on the purlin.

Profile 3 sheets are generally fixed using 6mm diameter fasteners and an 8mm diameter hole should be drilled through the sheet.

Notes: When fixing to timber purlins, BS 5268: Structural use of Timber, recommends that the minimum edge distance of the fixing should be five times the fixing diameter to avoid undue splitting of the timber.

Fasteners should be installed perpendicular to the plane of the roof.

With some types of insulated cladding, or where sealant has been used, sheet settlement can take place. It may be necessary to retighten the fixings after a suitable period.

 

Product range

Profile 6

Description

Profile 6 is a high strength fibre cement sheet with polypropylene reinforcement strips inserted at precisely engineered locations that run along the length of the sheet. This provides maximum impact strength without affecting the durability of the product.

The reinforcing strips within Profile 6 only become effective when the sheet is fully fixed.

Profile 6 has a very broad appeal. It is designed for roofs of 5° pitch and over and for vertical profiled sheeting in both single skin and insulated constructions.

A comprehensive range of accessories is available and apart from the natural grey finish, sheets and accessories can be supplied in a wide range of colours (see pages 43).

A+ Manufactured in the UK, Le Fong’s fibre cement profiled sheeting can achieve up to an A+ (the lowest environmental impact) in the Green Guide to Specification.

Farmscape Anthracite

Description

The Farmscape product range is designed to reduce the visual impact of buildings on the landscape by giving them a weathered look from new. This is done by applying a surface pigmentation to the top surface of the sheet during manufacture. Unlike a dense layer of gloss paint, this process allows the distinctive texture of the fibre cement substrate to show through and give the product a far more natural appearance than that traditionally available to planners and designers.

Features of Farmscape

  • Economically priced product for buildings that have to blend into the landscape
  • Factory-applied matt finish
  • Vapour-permeability minimises condensation
  • Non-fragile material suitable for HSG 33 applications
  • Easy to install and fix

Technical data

As for Profile 6, see pages 36-37.

Fittings

A limited range of fittings is available for the Anthracite sheets but the full range of Profile 6 fittings is available in Natural Grey.

 

Profile 3

Description

Profile 3 is easy to handle and is suitable for small structures in the agricultural, industrial and domestic sectors, such as garages, general purpose sheds and smaller buildings.

A comprehensive range of accessories is available. The sheets and accessories can be supplied in a wide range of colours (see page 43).

Insulated systems

Built up systems using either a fibre cement or metal lining tray, together with a quilt insulation, have commonly been used in conjunction with fibre cement sheeting.

In more recent years, rigid insulation boards sometimes supported in a T bar grid, have also been used. There are other methods of insulating a roof that may be more appropriate for the design of the roof structure and the required thermal performance.

Please contact Marley Eternit for further advice.

Colour range

Accessories

Description, properties and performance

Identification

Le Fong offers a comprehensive range of products fabricated from a man-made fibre formulation, including profiled sheets, fittings and rainwater goods.

The range of profiled sheeting products allows design flexibility and speedy construction with overall economy for the roofing and vertical profiled sheeting of all types of buildings, including industrial, commercial and agricultural. It is a material that will comply with the Building Regulations and the Building Standards (Scotland) Regulations.

Quality

Profiled sheeting is manufactured in accordance with a quality system registered under BS EN ISO 9001 and to the European BS EN 494 product specification for Class 1X sheets. Marley Eternit also operate in accordance with Environmental Management System BS EN 1S0 14001.

Description

Profiled sheeting is manufactured from Portland cement and water, reinforced with natural and synthetic fibres.

Thickness tolerance

Profiled sheeting thickness tolerance is ±10%, but not exceeding 0.6mm, as laid down in BS EN 494.

Impact resistance

The Test for Non-Fragility of Large Element Roofing Assemblies, ACR(M)001:2014, consists of a 45kg bag being dropped from a height of 1200mm onto a fixed sample of roofing. It is intended to provide information about whether the roof can support the instantaneous loads imposed on it by persons stumbling or falling onto it. A roof is classified as fragile if the bag passes through the roof assembly.

If the bag is retained on the test assembly and no other drop tests are carried out, the assembly shall be classified as Class C non-fragile assembly. Profile 6 sheets meet this requirement. The reinforcing strips within Profile 6 only become effective when the sheet is fully fixed.

Sound insulation

The average sound reduction index over the usual measurement frequency range of 100 to 3150Hz has been calculated to be:

  • Profile 6 single skin – 28 decibels
  • Profile 3 single skin – 27 decibels

Breaking strength

The minimum breaking strength for profiled sheeting is defined under BS EN 494.

The minimum against grain breaking load (purlin to purlin) for Profile 6 is 4250N/m. The minimum with grain bending moment at rupture (ridge to ridge) for Profile 6 is 55Nm/m.

The minimum against grain breaking load (purlin to purlin) for Profile 3 is 1400N/m. The minimum with grain bending moment at rupture (ridge to ridge) for Profile 3 is 40Nm/m.

Installed weight

The approximate installed dry weight of single skin profiled sheeting with fixings and the required side and end laps is as follows:

  • Profile 6 single skin – 17.0kg/m2
  • Profile 3 single skin – 14.5kg/m2

Fire

External fire exposure: the sheets have a P60 (external SAA) rating to BS 476: Part 3: 1975, and can be classified Class 0 in accordance with the Building Regulations. Under the European Fire Test Standards, Marley Eternit fibre cement profiled sheets are classified A2 to BS EN 13501-1:2002 and are considered to fulfil all requirements for external fire performance of roof coverings without the need for testing, in accordance with Commission Decision 2000/553/EEC.

Fibre cement profiled sheeting can be classified as non-combustible under the Building Standards (Scotland) Regulations.

Water tightness

Fibre cement complies with BS EN 494: Clause 5.3.4.

Moisture content

When new, fibre cement sheeting has a relatively high moisture content. If humid conditions prevail, damp patches (without formulation of droplets) may appear on the underside of the sheets. This phenomenon is in no way detrimental to performance and will disappear within 12 months, in the course of natural exposure.

Condensation control unit

Whilst Profile 6 and Profile 3 are watertight, the sheets have the ability to absorb up to 25% of their dry weight in moisture and dissipate it in more favourable conditions. This material characteristic has a significant effect in reducing condensation occurrence.

Effects of chemicals

Over the years chemical and industrial atmospheric pollution will cause a slight softening of the surface of natural finish fibre cement sheets. The acrylic paint finish provides added protection against many acids, alkalis and solvents normally found in the atmosphere.

Where fibre cement is to be used in particularly aggressive atmospheres, with higher than normal concentrations of acids, alkalis, fats or salts, please contact the Marley Eternit Technical Department for advice.

Biological

Profiled sheeting is vermin and rot-resistant, but lichen may grow on the outer surface. For advice on removal, please contact the Marley Eternit Technical Department.

Light reflectance

Mean results for natural grey sheets are 40% dry and 16% wet, using magnesium carbonate as 100%.

Thermal and other movements

Profiled sheeting is designed to be minimally affected by frost or climatic temperature changes.

For buildings in which higher than normal temperatures occur, or in areas which are expected to be subjected to sudden changes in temperature, special considerations may be necessary. (Consult the Marley Eternit Technical Department for recommendations).

Thermal and other movements

The amount of movement is negligible, but it is necessary to provide movement joints in association with the structural framework. (For details of movement joints, see pages 66-67). The co-efficient of linear expansion for profiled sheeting is 8 x 10 -6m/mK.

Thermal conductivity

Profiled sheeting has only low thermal conductivity when compared with other sheet roofing products. This serves to reduce heat build up in summer and heat loss in winter.

Thermal conductivity = 0.48 W/mK.

Durability

In normal atmospheric conditions, profiled sheeting may be regarded as having a normal life of at least 50 years, but the durability of the fixing accessories should be taken into account.

Atmospheric pollution is not normally sufficiently concentrated to be harmful. Measures should be taken to prevent corrosion of the fixing accessories, e.g. by the use of plastic washers and caps.

Profiled sheeting is resistant to most forms of atmospheric attack but, with age, becomes less elastic and a small deflection will be experienced, which may make it less resistant to impact. Its transverse strength, however, is maintained.

Maintenance

Profiled sheeting in natural grey finish requires no routine maintenance. Decorative or preservative treatment should be renewed or treated as necessary.

Fixings and washers may, however, deteriorate and should be inspected at intervals according to the type of fixing and degree of exposure.

Appearance

When a painted finish is applied, the colour intensity will reduce due to weathering, but when the roof is viewed from a reasonable distance the colour intensity will appear harmonious.

Best Practices of Installation

Handling & Storage

From installation process to in-service application, Le Fong roofing sheets shall be protected from humidity exposure (stored in closed area) to prevent efflorescence from occuring on the surface of the sheets.

Refer to distributor or follow recommendations as per technical data sheets for the maximum height of stacking.

Corrugated Sheets

Lifting and carrying of the sheets to be done by two persons in longitudinal position as shown in Figure b.

Do not drag the sheets or attempt to lift it from the end, horizontally as in Figure a.

Storage

  • Sheets to be stored in dry and enclosed area.
  • Sheets to be placed on a flat surface.
  • For large volume storage, place the pallet supports in between every stack of 100 cm height with a maximum of 4 stacks

 

Health & Safety and Assembly Guidelines

Health & Safety

Dusts may occur when handling quartz containing products such as concrete, clays and fiber cement during machining processes such as cutting, sanding and drilling. Inhaling air of high dust concentration may cause irritation to respiratory system, skin or eyes.

Working under high concentration of fine quartz dust which may penetrate the safety mask for long term period may affect the lung and thus, the following need to be observed;

1. Avoid inhaling dusts by using cutting tools together with dust exhaust system.
2. Work in a well-ventilated area.
3. Avoid direct contact of dust with eye, skin and direct inhalation by wearing the appropriate Personal Protective Equipment (PPE).

The basic PPE as per the safety recommendations are safety helmet, mask, gloves and safety boots. Also, consider safety gears for working in height during installation.

Product Assembly

Installers are not allowed to step on the Eter product directly during installation or maintenance. Eter roof sheets are not designed to support the direct load of end user walking on top of it as this may lead to cracks and subsequently, accidents.

Use a layer of wood planks on top of the sheets as the cushion/ platform for mobility during installation stage as per figure shown below.

Sequence of Installation

The size of trim at the edge is based on the end lapping distance (length) and the side lapping distance (width).

General Installation Guidelines

Corner Trimming

a. Stacking of waves for the four sheets at the corner.
b. No structural support in between waves of the sheets.
c. Large gaps between the wave of the sheets.

Due to the incorrect practice in installation:
– Structure breaks in time of installation or during in-service stage.
– Allows penetration of water through the gaps (poor water tightness).

The benefits from correct practice in installation:
– There is no stacking of the four sheets at the corner.
– The sheets are structurally supported on one another.

Trimming Distance

For flat roofing (pitch angle below 8o), consider the end lapping distance as 250mm and apply a strip of elastomeric sealant all along the overlap.

Fixing and Fasteners

The fixing points on the Eter surface are recommended to be pre-drilled first with the the drill bit diameter of 2mm larger than the diameter of the screws.

Direct nailing to the surface of the product is strictly prohibited as this will result in cracks surrounding the fixing holes and underneath the sheets which will allow water to seep through.

Type of Connections

There are two types of connections in installation of Eter products i.e the use of timber purlins and metal purlins.

Kindly follow all the guidelines and correct practice of installation as recommended such as purlins spacing, screw fixing distance and etc to avoid defects or failures due to poor and incorrect practice of installation.

Installation Guidelines

Standard Dimensions

Comes with 6 waves and available in two different thicknesses, 5.0mm and 6.0mm. Due to its higher valley height, it gives stronger mechanical properties than the other products.

Recommended Assembly

Screw position: Fix the screws at the 2nd and 5th wave

Purlins Spacing

The structural support (purlins) is available in timber or metal.

Maximum spacing between purlins are given as;

1200mm for 5 mm thickness of Eter 6 and as 1450mm for 6mm thickness of Eter 6.

The actual purlin spacing is depended on the product length purchased and its corresponding end lapping value based on the roof pitch.

Roof Pitch and End Lap

Corner Trim

To avoid four times thick stacking at the corner during the roofing laying, corner trimming is required. For Eter 6, the side lap trim length is 115mm (see Figure below) while the end lap trim length is based on the roof pitch.

Installation Guidelines for Eter 14

Eter 14 comes with 14 waves and available in 4.0mm thickness.

Recommended Assembly

Purlins Spacing

The structural support (purlins) is available in timber or metal.

Maximum spacing between purlins are given as;

850mm for 4 mm thickness of Eter 14.

The actual purlin spacing is depended on the product length purchased and its corresponding end lapping value based on the roof pitch.

Roof Pitch and End Lap

Corner Trim

To avoid four times thick stacking at the corner during the roofing laying, corner trimming is required. For Eter 14, the side lap trim length is 75mm (see Figure below) while the end lap trim length is based on the roof pitch.