Damp - then Plaster Skim Before or After Tiling - TilersForums.com

[TheRealRobG]

Hi all.

I'm re-fitting a downstairs toilet and utility room. When I pulled out the old concealed cistern, I could see that it has been leaking for some time (about 1 drip a second, so quite badly). The cement floor under the cistern was sopping wet, and moisture had soaked a good 12 inches up the plasterboard and timber. There's quite a lot of black mould. I ripped out all the plasterboard (and worst affected timber) and am trying to dry out the room as best I can with a heater and de-humidifier. Construction of the house is timber frame with plasterboard throughout. I assume it's going to take a few weeks to fully dry the floor, as there must be gallons of water soaked into it, but in the mean time I want to try to work around it as best I can without causing any more problems.

I will replace the rotten timber with new and then install 12mm Aquapanel for the first run up from the floor around the room. I'll lay the lower edges on a strip of polythene so it doesn't wick up any more moisture from the floor.

Then I plan to apply 12mm square-edged plasterboard for the rest of the way to the ceiling.

After that I want to start tiling the wall up to just above the basin level with the top of the cistern. The wall above will be skimmed with plaster and painted.

Would it be better to have the top half of the wall skimmed after tiling, or have the whole wall skimmed and then tile? If possible, I'd like to tile first, as I won't have to wait days for the plaster to dry first.

The floor will be last. I need to scrape off the residue from rubberised lino adhesive then I plan to prime it and tile it. I'm not sure how long I'm going to need for the floor to be fully dry. I guess when the room can be left for 12h and not be significantly more damp than the rest of the house.

The only thing that really concerns me is the 100mm strip of damp cement floor trapped in the cavity which I'll effectively be sealing in, but I thought this moisture should wick back across the cement floor and into the room to be removed by the dehumidifier...

Thanks for any advice.

Rob.

 

[Gall.B]

Plaster the ares not to b tiled before you do the tiling is done far neater job, would avoid tiling onto plaster.

What size/type of tile is it Rob?

 

[TheRealRobG]

Thanks for the reply.

Tiles are wall/floor tiles 9.5mm thick and 300mm square. I've decided to build a false partition 900mm high about 120mm out from the wall to mount the basin on and contain the pipework. I'm going to tile the face and top edge of that. Easier than constructing a standalone pedestal just for the basin.

I guess I can get him to skim down to the top of the false partition.

Here's my sketch:



Rob.

 

[White Room]

That should be fine but preferably before any tiles are fixed..

 

[tilerbob]

if you want to jump right in and start tiling, why not start from the floor and work up
to the cistern if possible, but dont tile the last top row of tiles.
you can then have the rest of the wall skimmed up to this point and the
plaster wont be all over the top row of tiles, which you can tile when
the plaster has dried.

cover the tiles with newspaper/masking tape for any flying plaster.

edit: yup, plaster first.