Repairing cracks in tile grouting

[News]

We have two en suite bathrooms, either side of the central wall in the house, and on the roof above is a large Victorian four pot chimney. The bathrooms were installed around thirty years ago, so the walls are probably now plasterboard rather than original lath and plaster. Within each bathroom is a recess, either side of the original chimney breast (one recess in each bathroom).

Due to failure of the flashing (?) on the chimney, water seems to have run down the inside of the granite wall until it hit both recesses where it came through - both recess are tiled. The result is that the plasterboard has swollen, and there is now a crack (1/8 inch or thereabouts) all around the external angles of both recesses, although the tiles themselves are still firmly in place.

The chimney problem is being fixed (not by me!), and the plan is to allow the plasterboard to dry, scrap out the cracked grout and replace. Does that sound reasonable, and how long should I wait for the PB to dry?

[Tricky Dicky]

The plasterboard will dry but if it has swollen as you imply it will not sh rink back. The only real cure is to replace the damaged section of PB. I wo uld make sure that the tiles are actually still firmly glued to the PB and not just wedged in place by the grout. If a repair is not possible and matc hing the tiles not possible as long as the tiles are secure you may just ha ve to put up with some wider than ideal grout lines.

Richard

[tabbypurr]

if they're firmly stuck, but I expect they won't be

months, I'd get on & grout, it won't stop it drying. Use waterproof grout.

NT

[News]

In message , Tricky Dicky writes

Excellent, thanks. Yes, I realise the PB will not shrink back, and yes, the tiles seem very firmly attached. The cracks are at the 90 degree outside corners of a recess, so happy to scrape off where cracked then refill, even though the join line will be wider than normal.

[News]

In message , Chris French writes

Good point. However, the leak above was very much a one off, caused by heavy rain and wind from an unusual direction. Many other people in the village had a similar problem. In our case, the problem is poor flashing (?) around a couple of chimneys. Scaffolding is in place as I type, so fairly confident the PB will dry over time, and future cracks unlikely. Fingers crossed ...