Cemintel Wallboard is an autoclaved, cellulose fibre reinforced cement sheet which is immune to permanent water damage and will not rot. It is specifically designed for use in the lining of walls in kitchens, bathrooms, laundries, toilets and other areas commonly known as 'wet areas' in domestic buildings.
Wallboard has a recess on both long edges so that sheets may be taped and set with Gyprock/ Cemintel jointing materials. Once jointed, it may be tiled, painted or wallpapered as desired. An appraisal by the Building Research Association of New Zealand (BRANZ Appraisal Certificate N97/007), confirms the suitability of the Cemintel Wet Area Lining Systems (excluding the Compressed Sheet Wet Area Flooring System) detailed in this technical literature.
Australian Standard AS3740 : 1994 'Waterproofing of wet areas within residential buildings' defines wet areas in two categories.
Category 1 wet areas; are those wall and floor areas enclosing a shower compartment, i.e. part wall areas of showers within bathrooms and ensuites.
Category 2 wet areas; are those part walls adjacent to fixed vessels such as baths, toilets and tubs, i.e. part wall areas within bathrooms, ensuites, laundries and kitchens other than the wall area enclosing a shower.
The Cemintel Wet Area Lining Systems offer proven, reliable and cost effective solutions to both categories.
Handling and Storage.
All sheeting must be stacked flat, off the ground, and supported on a level platform. Care must be taken to avoid damage to edges, ends and surfaces. Material must be kept dry, preferably by being stored inside the building. Where it is necessary to store sheets outside, they must be protected from the weather. Sheets must be dry prior to fixing, jointing and finishing.
When cutting or grinding fibre cement sheets using power tools, always ensure the work area is well ventilated. An approved dust mask (AS1715 and AS1716) and safety glasses (AS1337) must be worn. Hearing protection should be worn where appropriate.
Control joints are to be installed in large spans of wall to allow for structural movement, and are to be positioned:
- In non tiled areas at not more than 7.2m spacings.
- In tiled areas at not more than 4.2m spacings. Control joints are to be constructed with a double stud, and allowance for expansion/contraction is to be made in both the wallboard and tiles.
The wallboard may be fixed to either timber or steel framing. Timber framing must comply with AS1684 : 1992 'National Timber Framing Code'. Steel framing must comply with AS3623 : 1993 'Domestic Metal Framing'. Studs shall be plumb and true, and spaced at maximum 600mm centres.
Noggings are to be placed between all studs at 1350mm maximum vertical centres. When an external shower tray or perimeter angle flashing is used, it is not permitted to fix the wallboard sheet to the bottom plate. An additional row of noggings must be placed 25mm above the tray or flashing to allow the wallboard to be fastened. Similarly, noggings are to be placed 25mm above a preformed shower base, sink or bath tub. Also provide suitable noggings to support the bath and other fixtures such as soap holders and towel rails. Wall framing may be checked-out to a maximum depth of 20mm to accommodate the bath or shower base flange. Alternatively, provide furring to ensure the face of the wallboard will finish in front of the upturn on the receptacle.
Extreme Climatic Conditions
When Cemintel Wallboard is fixed to steel framing in extreme climates, insulating materials are required between the wallboard and the frame to isolate components subject to thermal movement. Wallboard Installation.
Generally, it is recommended that all Wallboard sheets be applied horizontally. This is to reduce the extent of joint visibility in glancing light conditions. Sheets may be fixed vertically in tiled areas or where joint visibility is not an issue. Butt joints must be staggered a minimum of 600mm in adjacent sheets. Avoid butt joints over doorways and windows. Where these are unavoidable, they are to be positioned a minimum 200mm from jamb studs, and formed on a stud. Install the bottom sheet first, with the lower edge a minimum 6mm clear of the finished floor. Fasteners are to be positioned a minimum of 12mm from the edge of the sheet and a minimum 50mm from sheet corners. Fasteners are to be left a maximum of 0.5mm below the sheet surface.