J
Joanne
Hi there new to this forum and thread. I stumbled across it looking for answers to a similar problem with areas of my grout in a new wet area. Did you ever find out the cause of the leak?? About to tell my builder to carry out checks on the plumbing in the cavity wall. The wet areas are patchy but spreading. They occurred within a week of using the shower and have gradually got worse over the past 2 months.
They are damp ( builder used a damp meter to read) but not drying out even with ufh on. The problem is slowly getting worse. The picture shows area 10 hours after shower last used