Internal Wet Areas - Sheet Membrane System

Product and System Installation Requirements

The installation of the Gripset waterproofing membrane system should be carried out in strict accordance with relevant, current Technical Data Sheet (TDS). All other materials used in conjunction with the membrane system must be compatible and approved by the manufacturer.

1. Substrate Preparation

Substrates to which the membrane is to be applied must be structurally sound and stable. All building surfaces which the membrane system is to be applied are to be installed as per manufacturers recommendations, in line with relevant building standards in force at time of the application. Surfaces must be smooth, dry and clean. Rough surfaces, voids, hollows and surface depressions to be evened or filled first and all brick/block surfaces to be pointed flush. All general surface defects including cracks to be filled and repaired – Refer to Gripset 11Y/DM repair mortar and Gripset SB Sealant. All surfaces are to be free of sharp protruding objects, loose material, de-bonded or existing coatings, curing membranes/agents, release agents, wax residues, foreign particles, laitance, algae and moss, grime, oils, animal fats, grease remains and any contaminants that could compromise the adhesion of the overlaid membrane system. Structurally unsound layers and surface contaminants are to be mechanically removed by abrasive blasting, blast tracking, grinding, high pressure cleaning or equivalent methods. Concrete to be cured for a minimum 28 days and screeds left to dry for at least 7 days prior to the membrane application. Leak control flanges are to be rebated into floor surface enabling lip of flange to sit flush with surrounding substrate.

2. Priming System Selection

Gripset GP Primer General Purpose Primer for porous/absorbent surfaces. Apply 1 x coat by brush or roller at coverage of 1litre/6m²

Gripset H20 Primer Single component primer for sealing cement based green substrates or surfaces with residual dampness. Apply 1 x coat by brush or roller at coverage of 1litre/6m².

Gripset E60 Primer - 2-part water based epoxy primer for sealing green substrates or surfaces with residual dampness and negative hydrostatic pressure. Apply 1 x coat by brush or roller at coverage of 1litre/3m²

Installation

  • Apply primer to floors, over shower hobs and turn up at perimeter walls to 150mm
  • Apply primer to shower walls to minimum 1800mm
  • Apply primer to bath hobs and surrounding bath walls extending minimum 150mm above bath
  • Apply OP primer to all PVC and metal fixtures, flanges and turn-ups of pipes/penetrations to where the membrane is to be applied, alternatively BRW PF detailing may be applied directly to porous materials without the use of OP primer

3. Membrane System Stage 1

Gripset BRW PFN High performance self-adhering waterproof sheet membrane. Installation Measure dimensions needed for the application and using a sharp knife or scissors, cut lengths required then re-roll sheet up in preparation for adhering to surfaces. The BRW-PFN sheet is to be adhered on all floor areas to be waterproofed, abutting edges of the walls of these areas. When applying BRW-PFN on sloped or graded surfaces, start by laying the membrane from the lowest point (nearest to drainage point) and working upwards to higher points (away from drains). Ensure overlaps formed are aiding drainage of water and not creating counter gradient overlaps. Over pipe penetrations, the BRW-PFN sheet is to be cut to enable the sheet to slide over penetrations. This is best achieved by measuring the pipe diameter and in the position where the sheet will cover the pipe, a cross “+”should be cut that is the pipe diameter length and sliding this over the pipe. When laying the sheet into position, remove approx. 100-200mm of release paper from the rear butyl rubber side and tack this onto the surface. Continue to slowly remove the rear release paper while the sheet is being unrolled and remove any creases or air bubbles with a flat trowel, heavy roller, dry sponge or float to ensure the sheet is firmly bonded to the substrate. Ensure the sheet is well pressed at overlaps, corners, edges and termination points. Trim any of the loose membrane around the upturn of the pipe from the section where the cross “+” was formed ensuring the sheet is firmly bonded around the pipe/penetration All sheet joins must have a minimum 50mm overlap. All overlaps and junctions are to be coated centrally with 100mm wide coat of Gripset liquid membrane. The use of protection boards are recommended to be used for following trades, avoid placing tools and equipment on exposed BRW PFN sheets

4. Detailing System Selection

Elastoproof B50 Joint Band: Elastic bond breaker joint band

Prefabricated Corners: Prefabricated 90° and 270 corners used with the Elastic Joint Band as the system bond breaker

Elastoproof Base Collars: Waterproof Elastic sleeves for sealing floor and wall penetrations

BRW PF Tape: Self-Adhering, Butyl Rubber, bond breaker Tape

BRW PF Squares: Self-adhesive butyl square for sealing floor wastes and leak control flanges

Installation

 5. Membrane System Stage 2

Gripset 38FC Single component, Fast Cure, fibre reinforced SBR latex membrane

Installation

  • Apply membrane by brush or roller over primed shower walls
  • Apply membrane to bath hobs and surrounding bath walls to 150mm above bath
  • Extend membrane over horizontal leg of water stops and turn up the vertical face
  • A minimum of 2 x coats is required to achieve the recommended coverage

Coverage

Walls: Applied at a minimum 1litre/m² forming a 0.8mm dried film thickness

IMPORTANT: Polymer modified tile adhesives must be used for direct fixing of tiles over Gripset wet area membranes All tiling to be carried out as per AS 3958.1 – 2007 "A Guide to Installation of Ceramic Tiles”