Waterproofing under acrylic shower base

Originally Posted by bosun

I'm installing a pre-formed acrylic shower base on 15mm compressed cement sheet on the ground floor. Wondering about the right way to waterproof under the base and at the floor/wall junctions, considering that the base is checked into the timber bottom plate & studs by 20mm. I'm also looking at waterproofing the shower walls up to 2m.

Any helpful comments appreciated.

thanks

Bosun

The full floor should be waterproofed to meet the standards, this includes the wall to floor interface on all walls and a waterstop angle across the doorway.

Leave a 3 to 5 mm gap between the shower base and wall sheet, fill this with a suitable sealant then apply waterproofing with a membrane along the bottom of the shower wall sheets to just cover the top part of the sealant, add a another seal up the corner to a minimum of 1.80m.

Seal all fixings with sealant inside the shower area.

As it's not practical to seal the recess inro the studs, do not be tempted to seal around the shower base to floor interface, or you will have no indication of a leak if the waste connection fails, and the do this quite often because of minor movement, so make sure the 'O' ring is spotlessly clean before connecting.

When sealing the floor, seal up the screw heads and tape or seal the sheet joints to stop the waterproofing leaking through it cures.

Good luck.

Originally Posted by bosun

Many thanks Oldsaltoz

I also came across an interesting point about priming the compressed cement floor sheeting prior to the applying the membrane. I'm told that a solvent based "etching" type primer is needed specially for the compressed cement sheeting rather than the general-type primer that you would normally use on Villaboard walls etc - is this special primer used around the trade?

thanks again

Bosun

Hi Bosun,

I suspect someone is looking for cover, I have never sealed cement sheets prior to waterproofing and never had a problem.

I might be that some less robust waterproofing systems need all the help they can get, all the wet-seal products are tested by the CSIRO and an independent mob call BRANZ as well the tile glue makers.

More info on the web site.

Good luck.