Tiling Bathroom Floor

[ajsaville]

Need a bit of advice on tiling my bathroom floor.The surporting joists are 4inch by 2inch and 16inch's apart at there centres.The floorboards are 4 & 1/2 inch's wide bye 3/4 inch.I was going to use 6mm hardiboard to strengthen.I know i need to screw the hardiboards down but do i need to stick it down aswell or could i over ply with 12mm wbp plywood.Any advice would be most welcome.

Alan,

 

[david campbell]

either way would be fine,personally i would ply as it's cheaper!
and i would use adhesive on the underside of the hardie if i were using it!

 

[ajsaville]

I take it i dont need to use adhesive on the underside of ply then just screw it down. Also if using ply i take it i still have to remove the remaining old vinyl tiles.

 

[mags]

I take it i dont need to use adhesive on the underside of ply then just screw it down. Also if using ply i take it i still have to remove the remaining old vinyl tiles.

No more nails or similar and screw every 2-300mm

 

[obobsmith]

I take it i dont need to use adhesive on the underside of ply then just screw it down. Also if using ply i take it i still have to remove the remaining old vinyl tiles.

Yes get rid of old vinyl tiles, and it won't hurt to use adhesive on underside of ply, remember to use a primer on the underside ( not tile face ) and edges of your ply.

 

[pete f]

ajas minimum ply thickness is 15mm so maybe backer board would be the idea screwed down 300mm centres

 

[pete f]

sorry ajas 150mm centres

 

[Daz]

Hi Alan,

I don't know if you've made a decision and commenced yet, or not? There seems to be a lot of confusing advice given (I know I'm confused by the replies).

Firstly, get all the vinyl tiles up.

Next, you need to asses how rigid your existing floor is and whether there is any deflection (bounce). If there is, then this needs to be dealt with using ply (18mm is recommended). When overboarding with ply, you should apply an acrylic primer (neat) to the underside and edges to seal it. Then stick the boards down with a flexible cement based adhesive (not no more nails / gripfill etc.!!), a 6mm trowel will be okay. Then screw the boards into the floorboards at 150 to 200mm centres. You will need to follow the adhesive maunfacturers instructions as to whether the face should be primed prior to tile fixing. Personally I use Ardex 7001 or Mapei Keraquick with latex when fixing to wood floors.

If there is virtually no deflection in the floor, you can use 6mm cement boards. Glue with a flexible cement based adhesive (6mm trowel) and then screw at 150 to 200 mm centres into the floorboards. You will then be able to fix the tiles using a single part flexible cement based adhesive.

I hope this makes sense.
Good luck.

 

[ajsaville]

Have got all the vinyl tiles up just removing adhesive thats left behind.Yep i have got a bit of bounce in floor so will go for 18mm ply i have got some flexi adhesive i must admit i never thought about using primmer on the ply.I take it PVA should not be used as a primmer.

 

[Daz]

Correct. PVA has no place in the tiling world! It's just wood glue really.

 

[Fred]

You need an acrylic primer, a good tile shop will stock it, or main outlets like Topps Tiles. PVA is a no no.

 

[White Room]

4x2's for floor joists:yikes:

 

[Daz]

4x2's for floor joists:yikes:

😳 I didn't spot that!

 

[White Room]

And 16" apart rather than 400mm centres:yikes:

 

[ajsaville]

Place was built in the 60's so i assume that was the reg's in those days.Now does that mean i will need thicker ply.

 

[White Room]

If there is'nt any noggins between the joists, fix some. I would use 18mm ply just for some extra strength

 

[Eddie]

Then stick the boards down with a flexible cement based adhesive (not no more nails / gripfill etc.!!), a 6mm trowel will be okay.

I've never heard of anyone using adhesive, between ply, and floorboards before. Never done this myself.

 

[Richardk]

What about 6mm No More Ply. Their instructions say use two beads of their Megastrength glue then screw down using 8 screws per sheet. Anyone done it this way? Any comments?