Plastering in Bathroom

[Clarkson86]

Hi all.

Had a new bathroom installed late last year and keep having problems with the tiling between the shower control unit and bath taps, we shower standing in the bath at the tap end.. The people who put the shower in channelled the wall behind the bath taps and put flexible pipe up the wall about 75 cm to the shower control unit, then plastered over and tiled. However I keep getting cracks between the tile joints and keep have to regrout, knock on effects a couple of the tiles keep (I say keep it has happened 3 times) popping off where water is getting between the cracks in the grout and also the water is leaking down the wall behind the bath, not major just annoying. When retiling I have used the appropriate Bal stuff to seal the plaster and tile. One of my friends thinks this is where the hot pipe for the shower keeps expanding and contracting. I have put this in the plastering section because I am wondering if I need to do something with the plaster first before I tile. Thought I would get some advice by posting on here, any thoughts

 

[joe-90]

Tiles on plaster really need tanking. Did you do that?

 

[Richard C]

I think your friend may well be right & using flexible pipe won’t have helped much either IMO; how thick is the plaster covering the pipe work? Don’t know what type of plaster you’ve used either but if there is insufficient depth in the plaster, it will still crack.

Tanking it may help it last a little longer but if it’s the plaster base that’s cracking due to expansion/contraction rather than the adhesive/grout, it’s wont cure the problem. Flexible adhesive/grout may help a little but it’s an unfortunate fact of life that if the job isn’t done with the correct preparation it rarely lasts; usually the only way to effect a permanent cure is to pull it off & start again.

 

[Clarkson86]

Thanks for the replies. It was not tanked, but I have been using Bal SPD for sealing (1 part Bal 4 parts water) and Bal White star adhesive. From memory the thickness of the plaster over the pipe is ~3cm. Speaking to other people today about this they have indicated expansion/contraction of the pipe, that it might possibly be best to take the column of tiles off that sit over the hot pipe, chip away the plaster over the pipe, box in somehow or put some metal mesh over the pipe (not touching) to allow for expansion and contraction, then replaster and tile etc. Any thoughts?

 

[Richard C]

3cm over the pipes is plenty; put 10mm of foam pipe insulation or even Polystyrene over the pipes & plaster over that. The pipe will then be able to move, expand & contract without disturbing the plaster & it will also insulate it from direct heat; that should take care of it.

One other thought; is the shower pumped & are the pipes well secured? If not, it could be vibration causing the problem but, again, the insulation should take care of it.

 

[Clarkson86]

shower is simply mains fed from a combi boiler, and I believe the pipes are well secured but only a guess.