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Waterproofing Concrete Decks and Balconies (Best Practice)




  • All surfaces to be waterproofed must be firm, clean, dry, sound and smooth. All grease, oil, wax, curing compounds, loose material, paint and any other contaminants must be removed, masonry surfaces must be pointed flush and surface defects repaired. New concrete must be cured for minimum 28 days.

  • External corners to be waterproofed must be bevelled to ensure a smooth transition of membrane from vertical to horizontal surfaces.


  • Installation shall be in accordance with AS4654.2-2012 Waterproofing membrane systems for exterior use - Above ground level - Design and installation, paying particular attention to Clause 2.6 Typical Termination Details. Tile installation shall be in accordance with AS 3958.1-2007 Ceramic tiles - Guide to the installation of ceramic tiles.

  • Install 12 mm fillet/bond breaker to internal corners using Admil SupaSeal PU. Admil SupaSeal PU is a Low Modulus, Hybrid Polyurethane, flexible joint sealant and adhesive that is free of Isocyanates and other hazardous raw materials and omits low odour.

  • Recess outside edge of balcony to accommodate Seaton Tile Edge. Install Tile edge using Admil SupaSeal PU and/or Class 3 galvanized screws. Seaton Tile Edge is a high grade Aluminium extrusion and is available in Clear Anodised or Powder Coated finishes.

  • Prime Seaton Tile Edge and all other non-porous substrates using WPA 160. WPA 160 is a specialised solvent free primer designed for enhancing the adhesion of subsequent membranes, adhesives, toppings and decorative finishes over porous or non-porous substrates.

  • Apply WPA 460 Primer to substrate to be waterproofed. WPA460 is a two component water based epoxy primer used to seal concrete and masonry surfaces.

  • Apply a minimum of two coats of WPA 500 or WPA 230 UV or WPA Rapid membrane to achieve the required dry film thickness. Ensure that the previous coat has completely dried before applying the subsequent coat(s). NOTE: All penetrations must be waterproofed. WPA 500 is a waterborne, fibre reinforced, flexible waterproof membrane designed for use under tile finishes. WPA 230 UV is an elastomeric, one part, fibre reinforced, UV stable, water based polyurethane membrane. WPA Rapid is a fast curing, waterborne flexible waterproof membrane designed for use under tile finishes.

  • Once membrane is fully cured, install CTA Eco Screed with Efflock, ensuring a minimum 1 : 100. CTA ECO SCREED is a pre blended screed underlayment consisting of graded sand, cement and additives. EFFLOCK is a high performance, solvent free, water based liquid additive, ideal for the bulk impregnation of cementitious building materials.

  • Allow screed to cure, then apply WPA 460 Primer.

  • Apply two coats of WPA 500 membrane or WPA 230 UV, ensuring that the first coat has completely dried before applying second coat.

  • Allow membrane to cure, then install Floor tiles using CTA Pro Premium or CTA Promaxset. PROHESIVE PRO PREMIUM is a premium quality, extremely high strength, polymer modified, cement based adhesive. PROHESIVE PPROMAXSET is a high strength, polymer modified, flexible cement based adhesive, which has been specially developed for installing most types of tiles.

  • Grout tiles using the appropriate colour of Polyblend Grout. POLYBLEND grout is a premium high quality polymer modified, flexible, cement based, coloured grout designed for grouting most types of tiles including ceramic, porcelain, natural stone and glass mosaics.

  • Install backing rod to all perimeter and intermediate movement joints and seal with silicon or polyurethane sealant.