1st Job: Travertine Wall Prep - Some pro advice needed!

[stiggla0]

Hi

Ive got some 300x600 x12.mm honed and filled travertine for my bathroom, Ive prepped my walls as thus so far:

12.mm moisture resistant pb dot and dabbed using drywall adhesive onto skimmed breeze block walls - do I need to supplement this with screw fixings through the drywall and plugged into the breezeblock? Ive been told that this shouldnt be necessary but wanted to check with you guys.

Many Thanks

[jwatson]

the only issue realy is its dot and dabbed onto the skim and not the actual breezeblock, would have been a stronger bond.
find out weight of tiles + weight of plaster board per m2 and use this guide i have copyed and checked out.
hope this helps.
1. Substrate weight ratings

A common question, how much weight can my wall support, here are the recommended max weight ratings in KG / m2

Plaster Skim on Plaster Board........20KG
Skim and Set Plaster...................28KG
Plaster Board.............................32KG
Sand and Cement.......................40KG
Cement Backer Board..................55KG
Hardibacker Board.......................45KG
Lightweight Tile Backer Board........40KG
Glass Reinforced Cement Sheet.....50KG
Gypsum Fiber Board.....................40KG

Remember to factor in the weight of the tile / m2 AND adhesive and grout
2. (Some adhesives are manufactured as lighter products).
3. Grout weight will also depend on how large the tiles are that you are using and the thickness e.g. a tiled area that uses 300mm tiles will have more grout than an area with 600mm.

Grout.........2KG / m2
Adhesive....4KG / m2

[diamondtiling]

Strengthen the walls with mechanical fixings, this will give you a much stronger and safer tiling surface.

[williamraff]

As above - but you might consider using Aquapanel screws - these will provide a corrosion resistant, positive restraint rather than relying on the passive restraint of the dot and dab -
peace of mind if you end up putting heavy tiles on.

[TTT]

Normally 12mm stone is just over the limit for plasterboard should really use a cement board or if you were dotting dabbing boards to the walls i would use Marmox board, light weight easy to cut and fix and completly waterproof cement boards are only water resistant meaning they will let water passs through them! I would have removed the plaster first and gone back to the block but id screw and plug through the plasterboard into the breeze block now. Good luck!

[TTT]

JWatson ive always been told that any plaster whether it has a bond coat or just a skim onto plaster board it still can only hold 20KG per M2 thats it.

[Rich]

I would mechanically fix as well, for the time it will take I think it is worth it.

[whitebeam]

Agree with TTT about the plaster weights.