Tiling a bathroom from scratch - Tile Advice

[Shultzy]

Hi all. My daughter has decided that she wants a new bathroom so its been gutted, and although I have been tiling for a good many years they have only been small areas; so advice is needed

The bathroom is 2.1m (7ft) square, with wooden floorboards.
The east wall is a stud wall, the north and west walls are brick, the south wall is stud with the door frame.
The bath is along the west wall with the shower in the south-west corner.

So bearing in mind that all the walls will be tiled the questions are:
can I use plain plasterboard for the walls?
is dot'n'dab acceptable for the brick walls or do they need to be screwed to the brickwork?
what backer-board for the shower area?
on the west wall how far from the corner of the bath do I put the backer-board?
do I put the units in before I tile or after?
do I have to use flexible adhesive and grout?

The floor will be tiled but without UFH. It has lots of boards that have been cut:
should I take up all the floorboards and replace with ply, if so is 18mm ok?
is waterproof mdf an alternative?
should I just board over the floorboards, if so what thickness?
I know I have to use flexible adhesive and grout on the floor.
Any other advice?

 

[WetSaw]

What size/type of tiles are going on the wall?

 

[Old Mod]

Any other advice?

Breathe!

 

[Shultzy]

What size/type of tiles are going on the wall?

not sure, but I don't think they will be extra heavy. I'm assuming that heavier tiles will require a different backing than plain plasterboard.

 

[Old Mod]

“The east wall is a stud wall, the north and west walls are brick, the south wall is stud with the door frame.
The bath is along the west wall with the shower in the south-west corner.

So bearing in mind that all the walls will be tiled the questions are:
can I use plain plasterboard for the walls?”

In dry areas and tile dependant
Pb can hold a maximum of 32kgsm2 so allowing 4kg for adhesive and grout, a 10mm porcelain would be about its limit. Porcelain averages 2.4kgsm2 per mm

“is dot'n'dab acceptable for the brick walls or do they need to be screwed to the brickwork?”

Yes, and use mechanical fixings too when Pb adhesive is dry. Dowels or wedi washers and screws (wedi washers are my choice)

“what backer-board for the shower area?”

Any wedi style waterproof board.
Delta, jacko, Marmox, etc.
Joints and corners taped and mechanical fixings, and tanking paste/paint over the top to seal and waterproof.
Cement style boards like Hardiebacker and Aquapanel are NOT waterproof and still require tanking.

“on the west wall how far from the corner of the bath do I put the backer-board?”

If your daughter isn’t in the habit of drenching walls when she bathes, then just beyond the dimensions of the shower area should be fine, although never hurts to do bath area too.


“do I put the units in before I tile or after?”

Better after, easier to tile and easier to completely seal the room from moisture.
Don’t forget studwork where you intend to fix units, or anything for that matter.

“do I have to use flexible adhesive and grout?”

It’s a better option for sure, antibacterial grout is a plus.

“The floor will be tiled but without UFH. It has lots of boards that have been cut:
should I take up all the floorboards and replace with ply, if so is 18mm ok?”

Your sole aim is to make the floor as deflection free as possible, add extra noggins if you can. If you’re intent on using ply then I’d probably remove old boards, Fix one layer 12mm ply screwed to joists.
Then apply wood glue all over the top, then add a second sheet of 12mm ply perpendicular to the first, screwing only in to first layer of ply, NOT in to the joists. Then cover with a 1mm antifracture mat and tile.
A better option is the use of GIFABoard or 22mm No More Ply, these are inert boards, and do not get effected by moisture or atmospheric conditions. They can be fixed direct to joists as they are structural, and can be tiled as they are, as long as they are primed correctly.

“is waterproof mdf an alternative?”

No!

“should I just board over the floorboards, if so what thickness?”

Chances are if the floorboards are as rough as you say, it could become unstable quite quickly.
If you’re going to all this trouble, are they worth the risk, I’d say not.

“I know I have to use flexible adhesive and grout on the floor.”

Correct.

 

[Shultzy]

Thank you for your excellent and informative reply. As usual another question, what spacing is recommended for the Dot'n'dab screw fixings to the brick walls?

 

[Old Mod]

Here’s an installation pdf from dukkaboard

http://www.dukkaboard.com/wp-content/uploads/2017/08/Dukkaboard-DTI2002.pdf

 

[Shultzy]

Thanks again for the info, I'll post some pictures once we get started.

 

[Shultzy]

More questions:
I've fixed the 2x12mm ply flooring.
Does the ply need any coating before I lay the antifracture mat?
1 or 2mm adhesive underneath the mat?
Can I use BAL Single Part Flexible Tile Adhesive for the mat?
Can I use BAL Single Part Flexible Tile Adhesive for the floor and wall tiles (they are 9.5mm ceramic)?
Powder or ready-mixed?
Is a 10mm notched trowel ok?