Deflection issue with No More Ply down

[Kevbos]

Yet I said put another 12mm of ply down preferably 18mm first to strengthen floor .I use ditra.to assure strength sticking to a solid wood floor .

And as your preferred method of fixing problem .yes the adhesive will stick tiles and not come up .but because adhesive so strong tiles will only just eventually crack as they the weakest now

 

[Stef]

Yet I said put another 12mm of ply down preferably 18mm first to strengthen floor .I use ditra.to assure strength sticking to a solid wood floor .

He's already put down 6mm nmp, if the sub floor was prepped properly then I would have used 6mm Hardie backer & then tiled.
I don't tile to ply & wouldn't fit ply over the top to try & strengthen the floor.
I would rip it out & start again but an elastomeric addy takes up a lot of movement.

 

[Kevbos]

Some tilers love hardie backer .but as I said if you prep floor properly with right thickness of ply you get no issue

And good luck getting that stuck ply up to start again .we were trying to overcome a problem .by what he said floor needed strengthening .I gave a solution .that does work .

 

[Stef]

Some tilers love hardie backer .but as I said if you prep floor properly with right thickness of ply you get no issue

15mm ply overlay BS + Ditra.
6mm Hardie glued & screwed or
6mm thermal glued & screwed.
I will use the one that's not going to give me a step into the bathroom.

 

[Kevbos]

That's ok but he's getting over a problem

Floor bouncing

 

[Stef]

Floor bouncing

& that's why I stated Ditra isn't going to help.
If the floors bouncing too much then it needs sorted from the joists up.

 

[Dan]

That's ok but he's getting over a problem

Floor bouncing

Stop double posting. I'm fed up of merging your posts.

 

[Flintstone]

Controversial Kev is your new nick name.

I have over boarded many many bathroom floors with nmp and not had any problems. I would judge deflection with my eyes, if you can see any movement when your walking on it or lightly bouncing on it then it's probably not right, shouldn't see any movement. But if there is some movement it's only gonna be the joists.
Don't bother putting anything over the nmp it's a waste of time.

 

[Deleted member 46792]

So I really have three options: 1) The correct way - rip up the NPM which will probably also destroy the floorboards. Fix/strengthen the joists so no deflection and lay 12/18mm ply floor, overboard with NPM or Hardiebacker. Tile. Expensive, disruptive and will make me cry.
2) The risky adhesive option - bearing in mind that the deflection is minimal a very flexible adhesive might resolve the problem. Only time will tell. 2 or 3 tiles would be affected. One commenter suggests he doesn't think i have a deflection problem in such a small room.
3) The raised floor option - Ply or hardiebacker. Adds 2 cm to the height of the floor. Will it definitely stop bounce after all that effort?

I hope the answer comes to me in the morning...night all. Thanks for weighing in.

 

[Deleted member 46792]

Controversial Kev is your new nick name.

I have over boarded many many bathroom floors with nmp and not had any problems. I would judge deflection with my eyes, if you can see any movement when your walking on it or lightly bouncing on it then it's probably not right, shouldn't see any movement. But if there is some movement it's only gonna be the joists.
Don't bother putting anything over the nmp it's a waste of time.

Cheers for your reply...what do you suggest?