Contract / insulation board on the floor

[DavidJ]

My local tile merchant recommended I put 6mm insulation backer boards over my floor rather than the concrete type as they're 100% waterproof and easy to work with.

Are they strong enough to take the weight of the bath and cope with me walking about on them while I do the rest of the job?

 

[WetSaw]

They don't need to be installed under the bath. What size tiles are you using as the majority of foam cored boards have a minimum tile size.

 

[Flintstone]

They do if he’s tiling under the bath or fitting a free standing bath. They aren’t suitable for a bath directly on the boards without tiles on. Personally I always prefer 10mm on floors. Glued and screwed.

 

[WetSaw]

I hadn't considered a free standing bath, mainly because I don't like them!

 

[Qwerty]

So is it a free standing bath @DavidJ ?

 

[Dumbo]

Speaking to jackobord once they tell me their boards are used in some car showrooms .
How you apply the backer will not necessarily make or break the instalation (it can do ) but you also have to make sure your background prep is up to scratch . Ie no deflection in joists and also existing boards fix well to joists .

 

[DavidJ]

It's not a free standing bath. I was just thinking about waterproofing under the bath in case someone spills water all over the floor and it gets under the bath.

The tiles are 600x300

 

[DavidJ]

I think I might be better off putting one of the concrete boards down on the floor and sealing it and using jackoboard on the walls - it gives me a bit more peace of mind

 

[Bill]

cement board not concrete board is the term.

 

[Dumbo]

Nothing wrong with jackoboard on a timber floor but I think they recommend 10mm as a minimum on timber . It's easier to cut and it's insulating as well it's also much lighter to handle. As for weight bearing it has been successfully used in car showrooms according to their tech department .

 

[DavidJ]

cement board not concrete board is the term.

Thanks. Duly noted.

Nothing wrong with jackoboard on a timber floor but I think they recommend 10mm as a minimum on timber . It's easier to cut and it's insulating as well it's also much lighter to handle. As for weight bearing it has been successfully used in car showrooms according to their tech department .

Thank you jcr. It would have been used successfully in car show rooms by people who know what they're doing rather than a numpty like me! I'd end up worrying about it. The 10mm is a bit off-putting as I'd like to minimize the lip into the room. I think I've managed to talk myself out of it.

 

[Tile seller]

I'm not sure if its correct but, I've always assumed that the cement boards will take more deflection out of a suspended floor than the othersort.
You can seal them up with primer and tape the joints to waterproof if required too.

 

[Dumbo]

Thanks. Duly noted.

Thank you jcr. It would have been used successfully in car show rooms by people who know what they're doing rather than a numpty like me! I'd end up worrying about it. The 10mm is a bit off-putting as I'd like to minimize the lip into the room. I think I've managed to talk myself out of it.

If your a numpty it can fail with cement board .

 

[Dumbo]

I'm not sure if its correct but, I've always assumed that the cement boards will take more deflection out of a suspended floor than the othersort.
You can seal them up with primer and tape the joints to waterproof if required too.

Cement board isn' waterproof it would have to be waterproofed. I have also repaired wooden floors that had cement board