Internal Reinforced Elastomeric Liquid Applied Waterproofing Membrane Systems for Wet Areas
With the majority of liquid applied elastomeric membranes a reinforcing fabric is a necessity as well as a bond breaker at the floor/wall junctions.
The majority of elastomeric liquid applied membrane systems require a minimum of three coats, with a weather dependant cure time of twenty four hours between each application.
It is advisable that you take it upon yourself to thoroughly investigate any elastomeric liquid applied system for its suitability for the intended use.
If you have a contractor do the job for you make sure you get a signed printed warranty certificate in duplicate, one for your records and one for the Council building inspectors records.
The areas to be treated must be swept and vacuum cleaned of all rubble and dust.
An optional perimeter angle is bonded to the floor substrate prior to the application of any wall linings.
All vertical internal and external corners in framework should be suitably braced so as to minimise any building movement in these areas.
Wall linings are then installed and fixed in position.
All water bar, tiling angles and hobs should be securely fixed in position.(Brick hobs should only be constructed from pressed common bricks)
A bond breaker as described in Australian Standard 3740-1994 should be installed at the floor/wall junctions. (Any vertical/horizontal junction except the door threshold)
A 50mm wide bond breaker tape (masking tape) is then applied over the bond breaker, bonding the tape edges to the vertical surfaces and the floor substrate.
Apply the manufacturers recommended primer over the areas to be coated and allow to dry completely.
Apply a liberal coating of the elastomeric liquid membrane to a manageable area and lay the reinforcing fabric into the liquid making sure that the fabric is totally saturated with the membrane medium. Cove the membrane and fabric over the bond breaker and up the wall lining face to a height of 150mm. (50mm higher than the top of a hob edge in the shower area)
At the drainage riser points make sure that the membrane and fabric turn down inside floor waste risers by 30mm and up around drainage risers by 40mm.
Extend the membrane and fabric up and over the brick hob or water bar angle so as to form a continuous and uniform membrane linking with all main areas being treated.(It will be an added bonus if you create a fall on top of the brick hob falling into the shower area before applying the liquid membrane system)
At the vertical internal corners of any shower area extend the reinforced liquid membrane coating from a height of 1800mm down into the shower area, make sure that the membrane coating has formed an angle of a minimum width of 50mm x 50mm at the wall/wall junctions.
At the door threshold apply the membrane into and up the face of the installed tiling angle.
Where the tap penetrations are in the face of the wall lining, the reinforced membrane must be applied to form a positive seal in this area.
Before applying the second coat make sure that the first coat is completely cured, curing time may vary in cold areas as much as seven days. If the membrane is cured apply the second coat using the same principles as in instruction eight of the above.
Repeat instruction nine.
With most elastomeric liquid applied membranes it may be necessary to wait up to seven days before any tiling application is started.
For peace of mind you should block any floor wastes and flood test the treated areas with water, drain after five days of testing.
Before any other trade works in the treated areas cover the floor surface with a substantial protective layer to prevent any damage.
After the tiler has installed the wall tiles and before he starts on the floor area check the main membrane area for damage from walked in tile chips and other damage.