What is the best way to waterproof villa board before tiling?
I am renovating my bathroom. The lining is villa board from Bunnings Do I have to seal the sheets prior to tiling or is using a waterproof membrane material to seal the corners enough?
If I have to seal the sheets, what do you recommend to seal them with? Most tile adhesives must be applied to a surface free from paint.
Since you're using villaboard, I need to direct you to James Hardie's Wet Area Fixing Manual
There you will find essential detail that you need to follow, especially for shower recess construction. As far as adhesives are concerned you might want to use a product such as Ceramabond (DAVCO 96163000), which is ideal for tiling on fibrous cement sheeting in wet area walls only. The sheeting must be free from paint and if you want to prime the sheets then use Davco's Ultraprime.
It is important that you follow the detail shown in James Hardie's document as far as the assembly of the shower recess with the bond breaker between floor and wall junction.