Plaster and tile bathroom walls

[johnopaulo]

Hi, I will eventually be putting up new stud walls around the bathroom. When I get everything else sorted first! I will be installing a 1200 shower unit and base but prioer to that I will tile the full wall onto aqualpanel for equal to the are af the shower eclosure. However the rest of the bathroom will be half tiled and the top half of the walls will be new plaster finish. My question is because these tiles are 600 x 300mm would I be best to continue with the cement aqualpanel around the bottom half of the walls to hold these tiles and if so whould I just have normal plasterboard on the top half for the plaster finish?

Second question, the tile board and plasterboard will meet neaty level surface to each other about the middle of the wall creating a nice even playing field. Do I tile first then get the plasterboard skimmed down to the finished tile line and then affix a tile edge or what is the proper way to do this?

Thanks

Johno

 

[Richard C]

Use waterproof backer board in wet areas, tape/fill the joints & tile straight onto that; make sure you extend the backer board to at least 200mm beyond the shower enclosure (up to a stud obviously). Use 12.5mm Moisture Resistant plaster board on the rest of the stud walls & mark where your ½ tile line will be; get a plasterer to skim the area not being tiled & waste the skim into the area just below the tile line; he must prime MR plasterboard with “Bond It” or similar before plastering; tile directly onto the unplastered area. You must use cement powder adhesive with that size/weight of tile & you must prime gypsum plaster or plasterboard with an acrylic primer before tiling (but don’t get it on the plaster your going to paint) to avoid a reaction between the cement & gypsum. If the part of the backer board outside the enclosure needs plastering, it must be treated with sealing coats of PVA at least 24 hours before plastering; tape the joints as usual. Do not use standard PVA on any surface that will be tiled or painted.

Use only quality trade flexible adhesive/grout of the correct type for your tiles; BAL Mapei (but not the stuff in B&Q) Webber etc. Don’t use cheap DIY products, they are generally crap. Read the Tiling Forum sticky & archive posts to avoid making potentially expensive mistakes.

 

[johnopaulo]

Thank you very much for your help Richard. Can I ask another question. I am going to have a tiler do the bathroom floor. I will have 25mm flooring. No marine ply or anything but i was going to put a 6mm ply sheet on top prior to tiling. Would this be ok for tiling on a bathroom floor i dont want any damp getting to the flooring. Should i membrane between flooring and plywood?

Cheers

 

[vv2806]

Read the sticky. 6 mm might be not enough. The ply should be WBP (external grade).

 

[Richard C]

What material is the flooring? Is it existing floor or newly laid?

6mm ply is definately not enough if you want to avoid early tile failure. The minimum BS for over-boarding is actually 15mm & this is what all the adhesive manufacturers recommend. It is, however, generally accepted that 12mm is sufficient in most cases; you should not go thinner than that. Sometimes a waterproof tile backer board is sufficient (hence my questions) & more suitable than ply but laying a membrane between the ply & original floor will achieve nothing. You don’t need to go to the expense of Marine ply, WBP uses the same waterproof adhesives for the veneers which is what’s important. Do not be tempted to use standard ply, it isn’t suitable as a tile base. You should also seal the back & edges (but not the tile face) with an SBR/acrylic primer.

As I said, take some time out & read the Tiling Forum sticky & archive posts to avoid making potentially expensive mistakes. Be very careful with your choice of tiller; believe it or not, not all who say they are can actually lay tiles but a decent tiller will know all of this & more.