How to deal with raised floor after tiling

[hexdex]

Hello all.

Ok, so I'm about to refit the bathroom which includes tiling over old floorboards. How is it best to deal with the increase in height for the door threshold after laying ply backing and tiles? I estimate an increase in around 20 to 25mm from bathroom to hall and wondered how people deal with this?

Thanks.

 

[terryplumb]

you can buy adjustable height door thresholds, in various finishes ,to take up around 15 mm diference.what is floor covering on other side, carpet and u/lay ? if so thats another 10 /12 mm

 

[rules&rulers]

20mm is acceptable,floor edge thresholds are available to cover the join on what ever is on the hall floor if anything.

25mm try to avoid that at all cost.

 

[hexdex]

Thanks guys. The problem is that if I use 18mm ply and typically 8mm tiles plus cement I think even 25mm is unavoidable. The other side is carpet atm, but will be laminate.

 

[terryplumb]

if you use fibre board underlay ( about 7 mm thick ) add the thickness of the laminate another 7/8 mm you are half way there . and the fibre board underlay is a great sound insulator .avoid the cheap spongy stuff.

 

[hexdex]

Yeah good point Terry. Senior moment there I'm afraid! Cheers guys.

 

[chappers]

you don't need 18mm over the floorboards 6mm should be fine if the floorboards are fixed well, alternatively you could bond and screw hardiebacker

 

[hexdex]

Thanks chappers but the existing floor is not the best. It's solid enough, but it's over 100 years old and a little hit and miss.

 

[chappers]

got a picture, if its so bad you think you need to go over it in 18mm, you are probably better off ripping it up and then relaying with ply.
If it's not level/uneven with bumps and hollows, no thickness of ply alone is going to fix it.
IMHO any floor that can't be fixed with 6mm and maybe some SLC probably is too far gone to overlay.

 

[vinn]

OP,
You need a dead accurate measurement from the old floorboards to the FFL of the hall - guessing is useless. The building trade works to measurements.

Typically, 18mm is not needed as an underlayment. 12mm is adequate for most possibilities.
6mm luan ply or cement board is also often used - dont use fibre board.
There are masses of threshold transitions to choose from.

Before fixing, you must be certain that no loose pipes or boards are covered by the u/layment.
You must also mark all joist positions and pipe runs before fixing the u/layment.
You tile under fixtures not around them.

 

[hexdex]

Thanks for the continued advice guys, much appreciated. To be honest the reason I settled on 18mm ply was after reading various info out there in interwebland. Though I would not be surprised if I dreamt it....such is my brain these days.

I'll post a pic tomorrow. The floor is mostly level and in good solid condition apart from a couple of areas where the boards were cut back to expose pipes etc. Though I will have to make some more cuts to fix and sock just one joists. If i had my way i would completely refloor it, but the boards continue u der the stud wall to the living room (downstairs bathroom). I also need to retain the bath whilst i fit the shower first.

Cheers.

 

[hexdex]

OK, here are a couple of pics of the floor. As I say, they are solid and fairly flat apart from a few areas where the boards have been cut for access.

What do you think?

On a separate note, but with regards to what you said Vinn, how do people get around the issue of tiling under the toilet when it's the only toilet in the whole house?

 

[vinn]

The boards look to be mostly in good shape.
You could even use flexi-adhesive and flexi-grout, & tile straight over the T&G. But maybe thats a little too far for a DIY'er?

Lifting, tiling under, & re-setting the WC is all done in the working day but its your house and you can tile around it, and anything else if you want - there wont be any significant knock-on.

 

[terryplumb]

as vinn said 12mm ply is fine. and your floor looks in really good condition. I have tiled on much worse ,many times, braced with 12 mm ply. you have to appreciate the object is primarily to limit movement and secondary to give a more even surface upon which to tile.that's why you have to screw the ply down with screws at 100 mm centres.you need a few hundred !! and get the screw length right as you do not want to penetrate the underside of your floorboards and hit pipes or cables. I assume you know that flexible adhesive and grout is also required .

 

[terryplumb]

there is absolutely no way that a flexible adhesive used to tile straight onto wooden floorboards , with no attempt to limit the natural movement of the wooden floor boards will work.it will result in cracked tiles in next to no time .if you do not believe me speak to the industry's technical experts at bal /granfix / unibond etc. the problem with cutting around WC pan, is if you need to change the pan in the future .