PVA vs Primers
Which should I use for tiling? PVA vs Primers for Tiling on Walls.
A common problem in the tile industry is the old PVA vs Primers one.
People, and certainly plasterers (who are murder for it) tend to think and use PVA glue as a primer when tiling walls. If you’re tiling over plaster or plasterboard and wish to separate the tile adhesive (which may be cement-based) from the plaster (which causes issues; cement and plaster don’t mix) then you can’t use PVA to do that.
Here is the problem. PVA is water-based so will break back down with water, and all tile adhesive will involve water. It’s as simple as that.
A primer will reduce porosity of the substrate you’re tiling to. But you need to use an actual primer, not PVA glue. This then prevents water from being drawn out of the tile adhesive quickly as it cures, which in turn increases adhesion strength of the adhesive, and solidifies your tile to the substrate or surface you’re tiling to.
PVA glue does NOT use acrylic polymers. So the water-based glue should be thrown out rather than using for tiling.
All tile adhesive manufacturers will make a primer that’s compatible with their adhesive ranges. And as much thought should be given to this as you give to the choice of tile adhesive.
You wouldn’t want to spend £1,000 on tiles, £300 on adhesives and grout, and then pay £5 for PVA and your tiles fall off, or £50 on proper primer and they stay on.
It’s not worth the headache of risking your tiles falling off. Especially when you’re in the room you’re always naked in, the bathroom or shower-room. Sharp tile glaze or porcelain tile cut edges will break skin and could chop off your wiggly pale bits.