Tanking basics - TilersForums.co.uk | Tile Forums

captain pugwash · 23-09-2008

I am about to start a DIY job on my bathroom and I have a few questions regarding tanking.

The new bathroom is now a combination of what was a separate toilet and bathroom so the walls are slightly different levels - I am embarking on the task primarily because we had a combi boiler fitted 12 months ago and the increased pressure on the old mosaic tiled shower has blown the old grout and adhesive out and the tiles are falling off the wall

The corner where I want to build a wet room style shower are outside wall/s which are rendered and plaster skim but since the existing tiles have blown, the plaster is coming off with the tiles so I plan to re-render on the solid brick and use that as a base for waterproofing the shower walls. One of the walls is flat and I plan to render along its whole length (this one used to have mosaic tiles which are now off) and the other is brick (again previously mosaic tiles now gone) and then nice solid render and plaster (the bit that used to be in the toilet) so levels are an issue

My question - is sand and cement render a good base for applying the waterproofing - like Homelux or Schliter - this would be my preference - or should I consider backer board on top of the brick - in which case the levels on one (as above) wall will cause a problem and and I make the bathroom smaller

If backer board is recommended can you tell me why - can I fix backer board to the brickwork direct (if so how) or do I need to consider batten ?

Thanks

**whitebeam** · 23-09-2008

Render will be sound if you don't want it fast track, It will need time to dry. Give it a couple of weeks before you apply any waterproofing

**wetdec** · 23-09-2008

Hi m8

welcome to TF

As your walls are a mess already I would say batten them out put up new 12.5mm plaster board then tape and tank the shower area with Durabase wp membrane.

Reasons

No hacking off
No plastering to be done
Pb and durabase cheaper than backer board
You have a good flat surface to tile to

Cheers

tiler