Hi,

I’m supposed to be tiling the walls of a bathroom in 450 x 300 x 12 Travertine tiles.

The existing walls are plasterboard which has been skimmed and is currently half tiled.

Theoretically I believe the maximum weight you should tile onto plasterboard is 20Kg / Square Metre and I suspect this will be more than that.

Unfortunately the house is of non-standard construction and I believe the plasterboard has been fitted with the “Dot & Dab” process so taking it down and fixing something new may not be very easy.

What are the practical alternatives? Would it really be a problem if I went ahead and tiled on the existing surface or are these maximum loadings really critical?

I did think of overboarding but the additional thickness would cause other problems around the bath etc.

Any advice,
John.

Plasterboard will take 32kg/m2 its the plaster coat that is 20kg/m2.

Tiled a lot of my house, bathrooms, kitchen, utility.
Old part of the house is dot an dab new bit some plaster on brick some insulated board on stud.
Have used big thick tiles and after 6 years no probs

12mm travertine will be way over what plaster can take, plus you also need to allow for the adhesive weight.
i have quite often gone over the 20kg/m2 for plaster by a small amount, but would not risk putting travertine on it.

i would remove plasterboard/skim and reboard it. if its a wet area use tile backer boards

To do it properly you need to tile on cement boards or dry plasterboards. If you are doing half tiles you should be ok on existing finish. Be carefull if going full tiles to ceiling though. Remember the quality of the finished job is only as good as the preparation.
Why not use a ceramic travertine look tile. There are lots of good copys out there. Just a thought.

Mines also tilled onto D&D PB, all fell apart at the bottom where the bath had moved enough to compromised the seal allow water into the PB which is how i now whats behind there but the whole of the rest of it is fine and the provious owner was a right pikey, so if he can get it (nearly) good enough any man can!

Daniel