Adding an en-suite

[pate_luv]

I want to build a en-suite shower room in my existing bedroom. When putting up stud partitions, what can i do if the location of the stud running parallel to the underfloor joists does not lie directly over a joist? This is especially problematic as the shower room will require new flooring (waterproofed chipboard) as existing is too flexible and has too many gaps to receive tiles.

Also what surface preparation does the plasterboard require before tiling, especially in the shower area?

 

[Richard C]

Fit timber noggins between the joists @ 400mm centres, & screw the stud sole plate/floor to those. If tiling the floor, don’t use any sort of chipboard, its carp, use WPB, minimum 18mm thick & screw fix every 200mm; make sure you support any joins with additional noggins or position over the centre of a joist. For the tiles, use a good trade quality, flexible adhesive & flexible wide joint grout (I only use BAL); it’s quiet expensive but will give a quality job that won’t all crack up after 6 months. Also check there is no undue flexing of the existing joists across the rest of the floor; you may have to fit additional noggins to beef it all up if the new floor flexes too much or, again, the tiling will crack up.

For the shower, you can tank out the whole area but, personally, I would use Aquapanel (or similar) & tile directly onto that; don’t use PB, if it gets wet behind the tiles it will disintegrate. For the rest of the walls you can use ordinary PB; you can tile directly onto that but I always prefer to skim the whole area first as it helps keep moisture out of the PB & will give a nice plaster finish above any ½ tiling etc. but opinions vary on this.