Hi guys n gals,

I'm after some advice from the more experienced tilers here, with regards to tiling on the lightweight metal stud walls they seem to be using nowadays!?!?! If it was just ceramic tiles going up i wouldn't be too concerned, as that was what was on there originally, but.... The customer wants Marble!
The whole job's turning into a nightmare... They have the thinnest silent flooring (at 600mm centres) i've seen to date, and walls you could blow over hehe!

So far i'm playing with the idea of screwing 9mm ply (at 150mm centres), then overboarding with backer boards for the walls. And putting in noggins in the floor with 22mm chipboard (existing), then overboarding with 12mm ply.

Any pointers much appreciated ;-)

These types of walls are poo but can with stand weights ok if they are boarded with Aqua panel type boards to hold the weight of heavy marble.. The cement panels will rigid them up more than say wedi type boards but extra noggings will need adding for support at joints etc..
Be careful when taking the original boards down as they will be screwed right into the frames of the wall and can twist them if you rive them about..

As for the floor, it will more than likely be on TGI joists and at 600mm centres.. so check for deflection issues.

For the walls I would use 12.5mm hardie over the existing walls, you may find the plasterboard could be 15mm which I've seen used more regularly recently thats because the studs on the metal system are 600mm centres..

Noggins on the floor, as you say and plenty of them but would use 6mm hardie on the floor, fixed with adhesive and screwed.

Mark.. if they are TGI joists , you cannot noggin them like you can normal timber joists.

Those horrible skinny things they call joists...is it sterling board they make them out of.

I did a job recently with metal studs, but I was lucky enough to be able to remove them and replace with in 4x2, then I put 2.4 x 0.6 sheets of 12mm marmox on top. For the floor with same type of joists, I used 12mm ply with 6mm no more ply.

Thanks guys, i feel a little better about the walls now..

Dave, that sounds like the joists.. These ones look like 2"X2" at top and bottom, with 1/4" thick OSB in between. Very flimsy, and definite deflection. I was just gonna add 2X2 noggins screwed through existing 2X2 at top, in the vain hope that it would tie it all in better. Do you think there would still be too much deflection with the 12mm Ply? Anything you can suggest?

Stewart, with the floor, was that on top of existing, or straight onto joists?

Cheers
Scott

That was on top of existing 22mm chipboard....

The deflection will not be in the TGI joists as they are very strong, it will just be in the covering and this will upgrading or overboarding to suit bs standards.

Okay, thankee kind sirs!