Which adhesive to use?

[granthathaway]

Hi there, i am about to tile my bathroom walls onto a finished plaster (beneath is solid brick and bonding), using large format tiles (416mm x 316mm x 9mm) I currently have 3 10L tubs of granfix multifix adhesive, but have heard that it's best to stay away from the ready mixed stuff. Would a cement based adhesive be better and more suitable? if so, which is the best to go for? And is it best to get flexinle or "non flexible" for the wall tiles? cheers

 

[Bubblecraft]

A 9mm ceramic including adhesive & grout is going to exceed plaster weight limit. Your limit for plaster is 20kg pm2. You will be in excess of 23kg pm2.

For that thickness of tile, you will need to either over sheet with plasterboard or mechanically fix a cement based board to your wall. If you do not wish to do this, you will have to reduce your thickness of tile to 7mm or less. Plasterboard would be the cheapest option & will let you increase your weight limit to 32kg pm2 but is not water resistant like most cement based boards so not ideal for shower areas.

I would defo recommend to use a cement based adhesive. The type you choose will depend on how fast you can tile. My recommendation would be Bal Rapid set with a pot life of around 45 mins. If you need longer, I'd recommend Bal CTF3. It has a pot life of around 5 hours but bear in mind, it does not contain a porcelbond and so cannot be used with porcelain tiles.

There is no need to go for flexible if you are tiling onto a cement based board or plasterboard as these are not living products.