Fixing plasterboard before tiling

[David Hearn]

I removed the old tiles from the kitchen a while ago, but found that a in some places, the plaster came with it (old 1930's semi). Attempting to repair the plaster was difficult (for me!) and as a result, I have a bit of a wobbly plastering result.

I thought I could cover for some of the undulations when I came to re-tile - however I realised that I need to pack out the tiles a little to fill in the gap between the wall and the worktop (long story, but I can't change it now!).

The gap (around 12mm in places) is probably too much to make up for with adhesive - so I wondered what else I could do - and I came up with plasterboard!

My plan is to plasterboard the wall from the worktop to the wall mounted cupboards (60cm gap?) and then just tile on top of it. It'll fill in the small gap behind the worktop, even out the wall, and give a better finish to tile onto.

However, I wish to fix it directly onto the existing wall. I'm guessing that plasterboard adhesive might be best - less likely to introduce undulations as screwing might - and doesn't require battens etc (which would make the tiles too far forward for my liking.

Any thoughts? The area to be tiled is about 60cm high max and about 3m long (with the final about 50cm being about 1.2m high - when the worktop ends - this taller bit will just be painted, not tiled.) Any problems with fixing plasterboard to walls with adhesive and then tiling? Grout cracking in future? Whole thing coming off the wall? Hollow sounding wall?

What thickness plasterboard should I use? The thinner the better for me

- but I don't want it flexing.

I've never used plasterboard before - I'm going to avoid any joins in the board where it is visible - so where I paint it, the joint will be under the tiled section. So I'll plan on using square edge sheets.

Thanks

David

[Nigel Molesworth]

You can get "thick bed" tile adhesive, but it's a bugger to use.

Plasterers use plaster to fix plasterboard, but any product that adheres to paper and plaster will do.

9mm will be fine, just dab adhesive at 150mm centres.

Either will do, make sure the joint is in the middle of a tile.

If you haven't used PB before, note that you can cut it in two ways: with an old saw, or (easier) cut through the paper one side, then fold back along the line until it cracks, then cut paper the other side.

[Set Square]

Note that the adhesive is quite stiff, and starts as a dollop which gets partially flattened as you push the board up the wall. Even so, you'll have a job to reduce the gap much below about 1/2" (sorry about the mixed units ) - so the surface of the board will be about 20mm out from the wall, when fitted. [It's a good idea to press the board against the wall with a substantial piece of straight timber (maybe 100 x 50 x 1 metre) frequently checking verticality with a level.]

My preference is the second method - it's a *lot* less messy. Use a straight edge and sharp Stanley knife to score the first side. It will snap easily along the score line, just leaving the paper on the other side to be cut.

[Nigel Molesworth]

If you want less, try something like "No more Nails"

[<me9]

If you mix the adhesive thinner and apply with a brush in strips 300mm apart and support the board after pressing in place you /should get the adhesive thickness down to 3mm. This is how it is used in Gyproc laminated partitions. You need a reasonably flat base with limited suction (pva coat) to be successful.

[micky104]

-- micky104