Best Substrate for Bathroom

[Steve H]

Hi Guys and Ladies,

Apologies from the start for my ignorance. I am about to start to replace my bathroom, I have a plumber/electrician professional to guide me but I am taking the lead on the tiling. I am looking for guidance on whether my plans are practical or not.

I will be installing a shower/bath at one end of the bathroom, I intend to take down the existing plaster board wall to hopefully reveal stud partitioning. The plumber will do his pipe magic fixing the necessary pipe runs, I then intend to build the wall with 2400x1200x18 wbp ply, sealing the reverse and edges with suitable? primer. Leaving 2mm expansion gaps and filling these with Silicon sealant. I intend to tank the corner at the end where the shower is down to floor level. Then tile with Porcelain Tiles, around the bath and to the ceiling.

1. Is this sufficient tanking, if I do experience a leak, the water will work its way to the floor (which will be covered below).

2. I've read that the ply needs to be fixed at 300 centres, I expect my studwork may be further apart than 300mm, I will be fixing some noggings in as strong points for shower fittings and screen but suspect that the gaps between studs could be 14-16 inches, will that be ok?

3. I am going to a BAL trade presentation tomorrow, I intend to use their adhesives, primers, what will be a good primer and adhesive to use for this job, I will not be looking for a rapid set, as I suspect this will be a slow job.

I am moving the radiator, the floor looks like it is chipboard/weyroc, most of the original building materials appear to be from wickes, so I will be cutting into the existing floor, I am not worried about the expense so is it a good idea to lift the whole floor, which will allow me to insert some kind of acoustic cladding in the void above the ceiling below (it always seems to go quiet in the kitchen just as the waterfall gushes in the bathroom). Would the same plywood be a good floor in the bathroom, with either and I'm asking for advice here, 6mm hardibacker, wediboard or marmox board. Would that give a stable enough substrate for ufh, slc and then the same porcelain tiles.

More apologies for the long posting, I appreciate any advice that you can give. This job will be my 3rd and biggest by a long way in my new career as a tiler.

Steve

 

[Tecnik2000]

18mm wbp is overkill for the walls you can use 12mm moisture resistant plasterboard, just nog the wall for load points, like cistern or towel rails etc making sure there's no flex..spend the money on a 25mm ply floor if you're tiling it fixed @ 300 to the joists

 

[doug boardley]

Don't use ply on the walls, use Hardibacker 500, especially in the shower area. 12.mm plasterboard will be fine for the other wall areas.For the floor I'd use 25mm WBP plywood and insulation boards to maximise the efficiency of your UFH. Adhesive wise, if you can get Mapei Keraquick, it is as good as anything Bal do and a lot cheaper

 

[Steve H]

Thanks Doug and T2000,
Walls with Hardibacker and thicker ply for the deck. Thanks for the tip about Keraquick. Next question is likely to be: My floor will be about an inch higher than at present, has anybody any good advice on materials or other for make a threshold from my carpeted landing into the bathroom?
Thanks for your patience.

 

[david campbell]

Thanks Doug and T2000,
Walls with Hardibacker and thicker ply for the deck. Thanks for the tip about Keraquick. Next question is likely to be: My floor will be about an inch higher than at present, has anybody any good advice on materials or other for make a threshold from my carpeted landing into the bathroom?
Thanks for your patience.

sound like you intend overboarding the floor boards with ply,why not rip them up add extra noggins and lay 25mm ply

 

[doug boardley]

Thanks Doug and T2000,
Walls with Hardibacker and thicker ply for the deck. Thanks for the tip about Keraquick. Next question is likely to be: My floor will be about an inch higher than at present, has anybody any good advice on materials or other for make a threshold from my carpeted landing into the bathroom?
Thanks for your patience.

As David, I thought you were dispensing with the existing flooring?

 

[Scott]

If the floor is changed for 25mm then insulation board, UFH and SLC and then porcelain i reckon an inch will be about right

You can get a variety of different door thresholds to cover tha height difference. You can also pack othe out on the carpet side to compensate if its not deep enough

 

[Steve H]

That's right, I am removing the existing floor, but I was calculating the thickness of the 25mm ply, insulation board, ufh, slc, addy and 10mm porc tiles. I am probably exagerating and worrying over nothing. Thanks for the advice. I know I will have more Qs as time goes by.