Waterproofing Accounts for 83% of Building Complaints.There is a statistic often quoted in the building industry. Waterproofing is 1.8% of construction cost but accounts for 83% of building defect complaints
Waterproofing Solution Selecting the correct membrane for your project is crucial. We work with the major waterproofing manufactures to ensure: rigorous profiling of products and design (the correct product for the project); also considering the appropriate elongation properties to allow for building movement and expansion joints. We work to ensure long term solutions that we warrant. We work with any number of different membranes including polyurethane and acrylic membranes where appropriate and where more brittle monomeric membranes might fail. We partner the major waterproofing manufactures who are committed to continue developing products to meet the Australian environment. Quality Solutions Quality solutions require correct diagnosis of the problem, selection of appropriate quality product and installation by qualified and experienced applicators. The Authority regards leaking showers as a serious and reoccurring problem that results from poor attention to detail during construction. Supervisors and installers should be aware of how the selected water proofing system is designed to work in conjunction with AS 3740—2004 Waterproofing of Wet Areas within Residential Buildings. General Notes: The Building Act 1995 offers further clarification of correct waterproofing procedure. The Standard Building Regulation (1993) through the Building Code of Australia provides Performance Requirements including Deemed-to-Satisfy Provisions for waterproofing of wet areas. The BCA Performance Requirement for Wet Areas (Part 2.4.1), states, “To protect the structure of the building and to maintain the amenity of the occupants, water must be prevented from penetrating- (a) Behind fittings and linings; or (b) Into concealed spaces, of sanitary facilities, bathrooms, laundries and the like. Performance Requirement (Part 2.4.1) is satisfied for wet areas in Class 1 and 10 buildings if they are waterproofed in accordance with AS 3740 – Waterproofing of wet areas within residential buildings. ISSUE Waterproofing of wet areas, such as shower recesses, has consistently been among the most commonly reoccurring category one (major) building defect. Home-owner complaints about defective waterproofing ranks third highest overall complaints received regarding building work. Materials ❐ Where water resistant cement render is not treated with an approved add-in mixture, complete waterproofing is required. ❐ Wet-area plasterboard must be installed to manufacturer’s recommendations. All cuts and penetrations must be sealed. ❐ Approved membranes that satisfy AS/NZS4858 must have a current test appraisal from CSIRO or similar. ❐ Plasterboard joints and nail heads in showers must be waterproof treated.  
Design ❐ Shower walls – are to be waterproofed to 150mm above shower floor substrate, or 25mm above maximum retained water level. Shower walls are to be water resistant to 1800mm from finished floor level. ❐ All internal and external corners and horizontal joints are to be waterproofed within the shower area. Plasterboard joints (outside shower) that extend inside shower areas must be waterproof. ❐ Unenclosed shower areas are to be waterproofed to 1500mm from shower. ❐ Tap-penetrations are to be sealed. Further, tap washers must be accessible without damaging the seal around tap penetrations. ❐ Floors and horizontal surfaces adjoining an insert-bath are to be waterproofed. ❐ Where the floor is waterproofed, the tanking of the walls is to be a minimum of 25mm above the finished floor level. Consequential damage due to defective waterproofing 
❐Bond-breakers must be installed, in cases where the membrane is bonded to the substrate, at all wall-to-floor and hob-to-wall junctions and at movement joints. ❐ Hobs must be constructed of masonry, concrete or similar material. Hobs should not be constructed of timber. Hobs must be adequately secured to the floor. 
>  
❐Hobs must be constructed of masonry, concrete or similar material. Hobs should not be constructed of timber. Hobs must be adequately secured to the floor. ❐ Water-stop angle to shower area must be finished flush with the top of the finished floor level. This angle forms part of the waterproofing system and must be installed prior to the installation of the waterproofing system. 
❐Enclosed hob-less showers must be fitted with water-stop angles. The vertical leg of the angle must finish a minimum of 5mm above the level of the finished floor. ❐ Unenclosed hob-less showers must be fitted with water-stop angles. The vertical leg of the angle must finish flush with the level of the finished floor. ❐ The membrane must extend a minimum of 50mm (onto the floor) over the outside of the hob face. ❐ Shower screens must be fitted flush to the inside (shower side) of the hob. ❐ Fixing penetrations must be sealed. Flashing in all wet areas apply to bathrooms and toilets, but do not apply to kitchens ❐ Frameless shower screens require a full floor waterproofing system or 1.5m radius from shower rose and, where water stop angles are installed angles must be made visible through tile bed. ❐ Water stop must be installed in all wet-areas doorways. ❐ Tap washers must be able to be changed without disturbing waterproofing seals. ❐ Full floor waterproofing will be required when using particle board and plywood sub-base. . 
❐Flashing in all wet areas apply to bathrooms and toilets, but do not apply to kitchens ❐ Frameless shower screens require a full floor waterproofing system or 1.5m radius from shower rose and, where water stop angles are installed angles must be made visible through tile bed. ❐ Water stop must be installed in all wet-areas doorways. ❐ Tap washers must be able to be changed without disturbing waterproofing seals. ❐ Full floor waterproofing will be required when using particle board and plywood sub-base. <<Back |
