tiling on plaster & lathe?

[Redeye]

I am in the middle of a bathroom replacement and would appreciate some input. I am putting in a bath with a shower over it. The end with the shower on it has been dry lined with aquapanel and skimmed so I can paint the bit I'm not tiling on. The back wall is a new partition which will be boarded with aquapanel and tiled on. The remaining wall (opposite the end with the shower on) is the one which I'm unsure about.

It is currently plaster and lathe. Do I :

1. Just tile straight on the existing wall because it's not really going to get that wet anyway.
2. Screw aquapanel straight on to this wall, then tile on top (there are only 2 vertical studs to screw to though, and the plaster and lathe is nearly an inch thick).
3. Dry line with 2x2 battens and aquapanel, then tile.

any ideas?

thanks dan

[daddyfreddy]

I'm a bit of a fussy git so I'd break the old plaster and lathe off and put plasterboard up. Of course you could always use aquapanel but I think it's overkill. Just seems a shame to go to all that effort and then leave a cruddy old lathe and plaster wall.

[EricP]

Rot in Hell youl vandal!!!

(Actually it's not a bad idea if the P&L is at all questionable, but very messy)

[Guy King]

The message from [e-mail] contains these words:

It's only fancy wattle and daub, after all.

[Redeye]

You're right, breaking off the plaster and lathe and fitting plasterboard would be ideal. But aside from the mess, the plaster is actually in pretty good nick so from that point of view it probably isn't worth it.

I guess the only other question is whether the plaster and lathe would take the weight of the tiles on top?

[Chris Bacon]

If it's sound you'll be OK. If it flexes or is cracked, certainly remove it, or overboard with something suitable.

[The Natural Philosopher]

If the surface is flat and level, tile straight onto it.

If not, you need to level it somehow, or it will look weird. How you achieve that is pretty immaterial.

[The Natural Philosopher]

Tiles are self supporting...they only need to be prevented from buckling. It takes very little to do that.

Think of a tiled wall as a very thin brick wall..

[Redeye]

I'd never thought of it like that.

Presumably they only act like a thin brick wall after you've grouted though? Until that point it's just the tile adhesive holding the tiles on, so the wall/plaster needs to be able to hold the weight of the tiles?

[Stuart]

Did you skim the Aquapanel where it is to be tiled .I thought the idea of Aquapanel was that only the tiles/cement should go on it as it needs to "breathe" for want of a better word . Personally I would have put 12.5mm plasterboard on the bit to be painted with the PB ending just under the top row of tiles .

As for the other wall I would think it better to get rid of the lath and plaster ( not plaster and lathe ,thats another situation entirely..lol) . Do the job properly and either plasterboard on battens if it isn't going to get wet or use Aquapanel with plasterboard on any areas that are not going to be tiled .

The Knauf site has useful info on the use of Aquapanel. Stuart

[The Natural Philosopher]

Yes, but thats not exactly a huge weight and the tile spacers will hold it up..plasterboard is pretty strong in compression.

I tend to tile, remove spacers and grout, as I go, upwards.

[EricP]

Depends on it's age and situation. If it's in a quiet place, not say near a door frame with a heavy door that has been slaming for 40 years, then it is probably ok. You may get some idea by tapping it and listening to the sound. If it sounds solid and not hollow or springy, it may be ok. Try drilling a few holes in it with a wood drill, some idea can be obtained by that method. THose old builders were very good in their methods with this stuff.

[Stuart]

I have just removed a false wall of ply with tiles and grout on and I'd be inclined to disagree about it not being heavy and also you say plasterboard is strong ..The Op is talking about Lath and Plaster ...Must be old as that hasn't been used in donkeys has it .??

Stuart

[Redeye]

Oh yes, it's old.

The original building dates from about 1750, and it was converted into a house around 1920. It's not a wreck by any means, but there's an awful lot to do to restore it to its former glory.

As for the lath and plaster wall (sorry for any confusion in the misspelling) - I think I may end up just replacing the bit I want to tile with plasterboard/aquapanel. As the join would be on the edge of a door frame I don't think it would be too bad to patch up.

One other really dumb question - are you supposed to countersink the holes in the aquapanel for the screws, or just bury the heads by screwing down hard? It seems to be a fairly brittle material so I don't want to crack it by overtightening.

[The3rd Earl Of Derby]

Find the studding and screw plasterboard to it over...erm!...Lattice plaster.

[Stuart]

I think you'll find the answer here .There are videos and also lots of other bits of info on the Knauf site .

[The Natural Philosopher]

It all depends on what you mean by heavy...most stud walls will take several tons in compression. Thats heavy.

50kg of tiles and tile cement is not heavy.