Advice on tile weight

[mark01]

I have ordered some porcelain tiles 600 x 300 8mm thick, I am now thinking I have to send them back due to weight. Its for an ensuite shower and the actual shower is moisture resistant plasterboard which is being tanked, this I know is ok with the weight.
The issue is the rest of the bathroom is skimmed plasterboard - well to be specific its old skimmed board with tiles removed and the old cement knocked off and some patching in places to make the wall flat to tile on.

I know good quality skimmed walls can take 20kg m2. The tiles weigh in at 3.5kg each and at 5.5 per m2 it comes to 19.25kg per m2 (excluding cement/grout so with this its likely to be nearer 23kg.)

The wall mentioned to tile on is 1.7m wide and will be tiled to a height of 1.2m so not very high. I know I could rip it out and re-board not something I want to do ideally, I cant add a layer of board over what's there as the shower tray wouldn't fit in. - So I could do with some advice please on if 23kgm2 is pushing my luck? or if the wall height can be factored in and the fact its just 1.2m high make it possible. (full ceiling height is only on the new tanked board)

Image attached - can see far right - new board (to be tanked) far left I had to patch a board missing after some boxing being removed rest of the wall is the previous Pb after tile removal and some places filled to level it out.

 

[DC Ceramic and stone]

Could you cut the old board out and put tile backer board in instead? Sometimes it is worth the extra hassle for piece of mind. As you say you are 3kg over, which to be blunt is still over. Hardiebacker or aquapanel would suffice.

 

[mark01]

Could you cut the old board out and put tile backer board in instead? Sometimes it is worth the extra hassle for piece of mind. As you say you are 3kg over, which to be blunt is still over. Hardiebacker or aquapanel would suffice.

It would be possible on one wall, but the hardiebacker wouldn't have much to secure it as the wall as the wall is paramount partition wall (stupid egg box stuff -house is only 16yrs old but typical house builders skimping on materials and time) so little in the way of structural stud work to secure the board to. The wood between the partition is just 3/4cm in width and depth, around 80cm apart, and no horizontal supports. The shower area I had to remove the top layer of plasterboard and replaced this with MR plasterboard which was screwed into the wood (only two vertical supports to screw through to,but also a lot of adhesive. The other issue is the opposite side would not be so easily as that's single skin pb paramount as well, by removing the last skin it also means pulling away all the cardboard egg box inside to get the board away.

I spoke to three tile shops yesterday and a couple of tilers and they said it should be ok they've put up heavier tiles on skimmed walls with no issues. They suggested just putting a row up and letting the adhesive go off hard before starting the next row, and said as the wall is only being tiled up 1.2m it shouldn't be an issue.

Don't know what advice to take to be honest, never seen any physical testing of tile weights on plasterboard to see the real fail point, I expect its higher and that figure of 20kk sqm is the very cautious figure. Either that or the industry is trying to push sales of tile backer board. Tiles seem to be getting bigger but most housebuilders still use PB.

 

[Waluigi]

The best way to sort out paramount board is to take the single sheet of plasterboard down, hack the cardboard squares off with the back edge of a handsaw- this sounds demented but it really works.

Then use building adhesive (gripfill, pink grip etc, solvent based) to bond CLS timber on its side to the plasterboard you are left with. Then the following day screw your board onto the CLS.

This also give you the opportunity to get the wall flat by bonding the CLS on perfectly Plumb and flat.

Prep work like this is fairly time consuming but it means you are starting the job on the perfect wall. Starting a job on a compromise often means the finished product is also a compromise.

 

[mark01]

The best way to sort out paramount board is to take the single sheet of plasterboard down, hack the cardboard squares off with the back edge of a handsaw- this sounds demented but it really works.

Then use building adhesive (gripfill, pink grip etc, solvent based) to bond CLS timber on its side to the plasterboard you are left with. Then the following day screw your board onto the CLS.

This also give you the opportunity to get the wall flat by bonding the CLS on perfectly Plumb and flat.

Prep work like this is fairly time consuming but it means you are starting the job on the perfect wall. Starting a job on a compromise often means the finished product is also a compromise.

Yeah I appreciate this, I had to tear down the egg boxing and glue cls to the back shower wall, insulated it and then boarded. In hindsight I should have done all the walls like this at the time!