Waterproofing slab before laying floor buttons....

Mr_Frangutz · Feb 27, 2024 11:29 pm

Hi All,

new here! WE recently (OMG, 6 years ago.. not that recent I suppose) renovated - and our prize product hasn't turned out as we were hoping. Got lots of questions but I'll break them all down over time

I was just wondering - how important is it to waterproof the concrete slab if laying 38mm batons for hardwood (19mm) floorboards?

The carpenter that laid our boards didn't water proof the slab, he basically fastened the buttons to the slab - as you would do with the wall frames. He said it wasn't necessary.

In discussion about some other issues, I'm now being told what he did is wrong and it should have all been waterproofed first before putting the buttons down. The batons went down about 1 year after the slab had been poured and the boards had been in our house for 2 months before being laid.

We have been here 5 years, and the boards seem ok (maybe they are drying more as I'm seeing some of the tongue and groove joins widen by a couple of mm).

Anyhow it got me thinking - when the frames are put down onto a slab, there is no water proofing, and there is no issue. Why should the slab be waterproofed for batons?

Just asking as I'm curious now.

alexp79 · Feb 28, 2024 4:56 pm

The slab is supposed to be waterproofed from the bottom side with the plastic film.

In the worst case scenario and to be 100% sure that the film was not punctured during the pour, it still might be a good idea to apply waterproofing spray under the battens (or to install a rubber underlay under the battens before nailing/screwing them to the concrete).

Certainly adding waterproofing additives during the concrete pour is the ultimate solution.

But with 38 mm battens and 19 mm hardwood floor I would have thought twice wether I want to lose almost 60 mm of my ceiling space for the sake of hardwood floor or better go for hybrid or engineered timber instead which usually do not require any battens at all.

Mr_Frangutz · Feb 28, 2024 9:31 pm

alexp79

The slab is supposed to be waterproofed from the bottom side with the plastic film.

In the worst case scenario and to be 100% sure that the film was not punctured during the pour, it still might be a good idea to apply waterproofing spray under the battens (or to install a rubber underlay under the battens before nailing/screwing them to the concrete).

Certainly adding waterproofing additives during the concrete pour is the ultimate solution.

But with 38 mm battens and 19 mm hardwood floor I would have thought twice wether I want to lose almost 60 mm of my ceiling space for the sake of hardwood floor or better go for hybrid or engineered timber instead which usually do not require any battens at all.

we actually had allowed for the batons/boards in the design stage. the builder ensured the slab was 50mm lower. Plus the new boards had to meet up with the existing - being a Reno/extension we had the old house levels to work with

Yes we have plastic around the slab - I suppose for the majority of it anyhow. obviously the top part of the slab isn't covered in plastic.

So overall, it's not 100% wrong to not waterproof the slab before we had put the batons down? Sounds like it should be ok (again I think about normal construction where the frames are put straight onto the concrete slab and it is not water proofed etc).

Thanks for getting back to me!

EmmaBarron3 · Feb 29, 2024 1:05 am

It's a good idea, even if your carpenter skipped it and things seem okay for now. Adding waterproofing can help protect against moisture, which is especially important for wood floors. If you start seeing changes in your floors, it might be worth considering. It's all about keeping your floors looking great for as long as possible.

Mr_Frangutz · Feb 29, 2024 10:02 pm

Mr_Frangutz · Feb 29, 2024 10:04 pm

EmmaBarron3

It's a good idea, even if your carpenter skipped it and things seem okay for now. Adding waterproofing can help protect against moisture, which is especially important for wood floors. If you start seeing changes in your floors, it might be worth considering. It's all about keeping your floors looking great for as long as possible.

thanks for this. Unfortunately I can't waterproof now. The batons are down and the floor is down. We have been in the house for 5 years.

Hopefully things are going to be fine

Thanks for advising though.

Ashington Homes · Mar 01, 2024 5:18 am

Just jumping into this thread which as confused me.

What product would you use to water proof the slab without damaging it with the battons?

For instance if you use a typical paint on product then you would destroy it when the battons were attached therefore negating any benefits.

Floor boards are direct stuck to concrete ever day without waterproofing, so I am not sure if the advice you were given is accurate.

Mr_Frangutz · Mar 01, 2024 8:23 am

Ashington Homes

Just jumping into this thread which as confused me.

What product would you use to water proof the slab without damaging it with the battons?

For instance if you use a typical paint on product then you would destroy it when the battons were attached therefore negating any benefits.

Floor boards are direct stuck to concrete ever day without waterproofing, so I am not sure if the advice you were given is accurate.

Hey There.

No problems re jumping in. My original question was "should I have waterproofed" the concrete slab before putting batons down. We have been told we should have. However I'm not sure if that is really the case. Hence why I was asking.

My argument is that wall frames are nailed directly to the concrete floor, as the carpenter did with our batons...

Just interested in understanding.

I attached some photos of what our carpenter did. Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅

Thanks.