On Wednesday, 3 January 2018 20:12:30 UTC, wrote:

In a moment of madness I had "stone tiles" put on the floor and walls of the bathroom.The shower tray is a pre-formed composite material that is tiled. The mastic pealed around the junction between the wall and floor of the shower (it's all covered in tiles, no plastic tray) causing a hard to diagnose water leak. When pulled, the mastic pealed off the tiles like opening a new zip. Is there a good "sanitary" sealant (what does that mean anyway?) that has good adhesion to stone tiles? Should I prep the area where I am going to reapply mastic in any way apart from leaving it all to dry out for a couple of weeks? Does dilute bleach cause mastic to fail which I use when there is a hint of mould on the mastic?

Thanks,

Clive

Bleach doesn't affect silicone IME. I assume you're using silicone not acrylic.

Probably the most common cause of silicone failure is expecting it to stretch. It can only move a small percentage of it's own size, and that often comes out to well under 1mm in practical applications. Overstretch it as things move and it fails. Do degrease before applying it, muck is the other cause of failure.

The most common cause of acrylic failure is using it. Only optimists think it suitable for bathrooms.


NT