ck-

Well in part, because I was expecting to have to silicon them, I left gaps in the grout between the wall and the floor..

I'm thinking that I might be as well to rake out the grout and re-do it between wall and floor. I have Bal flexible waterproof floor grout.

After all, I have a very thorough tanking underneath, and so the water will eventually find its way to the drain, or just evaporate back out through the grout.

I have wondered whether putting sealant in there actually makes things worse!

Thanks again for all the advice.