How to Waterproof Using Express Wet Area or Pro Rapid Waterproofing - Dunlop Trade

How To Waterproof – Express Wet Area & Pro Rapid Waterproofing

Before You Start

Before you start your waterproofing project it is important to get an understanding from your local government requirements and AS3740 for waterproofing in wet areas prior to carrying out a waterproofing project. The minimum requirements are as follows:

  • Full floor within shower recess.
  • Minimum 100mm over hob and onto the bathroom floor.
  • Minimum 150mm up walls within shower recess.
  • The wall to wall junction(s) within shower up to a minimum height of 1800mm or 80mm above shower rose.
  • The full bathroom floor if it is made from timber, plywood or particleboard or if it is above ground floor or if it has a floor waste.


Step 1

Ensure surfaces are sound and dry and floor sheeting materials are installed to manufacturer’s instructions. Remove all contaminating materials such as dirt, oil, paint and any cured material. Prime all areas to be waterproofed with Dunlop Primer & Additive or Dunlop Multipurpose Primer according to instructions. AAC Blocks will require 2 coats of primer.

Step 2

Prepare Dunlop Waterproofing Tape to be cut and applied to the corner of the shower

Step 3

Prepare Dunlop Waterproofing Tape to be cut and applied to the wall and floor junctions, and the corner junction. Ensure there is a 25mm overlap on the corner junction when this tape is applied.

Step 4

Measure and apply Dunlop Waterproofing Tape over the drainage hob, ensuring there is a 25mm overlap between each piece.

Step 5

Dunlop Waterproofing tape can also be used to waterproof shower roses for taps and shower heads. Measure, cut and apply Dunlop Waterproofing Tape over these. Tape can be stretched to fit over the outlets.

Step 6

Apply the first coat of Dunlop Express Wet Area Waterproofing or Dunlop Pro Rapid Waterproofing with a clean paint brush or roller so that surfaces to be waterproofed are completely covered with a generous coat, ensuring a minimum thickness of 0.5mm (wet film thickness) to provide a 0.25 dry film thickness. Allow 1 – 2 hours drying time before applying second coat.

Step 7

After 1 – 2 hours, apply the second coat of the Dunlop Express Wet Area Waterproofing or Dunlop Pro Rapid Waterproofing membrane in the opposite direction to all areas. Drying times will vary depending on humidity, surface temperature and porosity of substrate.

Step 8

On walls, each wet coat must be 0.5mm thick (this will dry to 0.25mm) and on floors, each coat must be 1mm thick (this will dry to 0.5mm). Total dry film thickness for walls is 0.5mm and for floors is 1mm.

Handy Hints

  • Your local government has waterproofing requirements as well as the National Construction Code for Tilings standards.
  • Allow up to 48 hours for waterproofing membrane to dry thoroughly before commencing tiling. Drying time will depend on temperature and humidity. The following Dunlop Tile Adhesives are suitable to use over Dunlop Undertile Waterproofing: Dunlop Wall & Floor Tile Adhesive, Dunlop Tile-All, Dunlop Trade Resaflex, Dunlop Universal Tile Adhesive, Dunlop Premixed Mastic Tile Adhesive and Dunlop Super Tileset.
  • To complete your tiling project, use Dunlop Coloured Grout that complements your tiles as well as the matching Dunlop Coloured Silicone. Grout joints can be sealed with Dunlop Grout Sealer.
  • What you will need: Dunlop Undertile Waterproofing, Dunlop Primer and Additive, Dunlop Reinforcing Mat, Neutral Cure Silicone, Paint Brush or Roller and Caulking gun (for silicone).
  • For Shower waterproofing try our Dunlop Shower Waterproofing Kit for easy project completion of your bathroom waterproofing project.