Damp concrete floor

Hi, I'm renovating a room in my house which has a concrete slab floor. I'm putting 50mm battens on it and 50mm Kingspan between - what I'm finding though is that water is collecting under the insulation at certain points - looks like damp is coming up from under - too much to be condensation, plus I noticed dark patches before I started, but wasn't sure if it was damp - now I know better. I think the sheeting under it may be pierced, or missing in parts. Can anyone suggest a method of dealing with this, short of digging it up and starting again? Ideally I'd like to be able to paint something on, or lay a membrane on top - I'm looking for something effective but preferably not too expensive. I need to deal with about 12m/sq if I do the whole floor.

Thanks,

R.

Reply to
Reuben_D
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I believe there are some epoxy based liquid applied membranes about - I've seem them on various "oak floor" websites usually next to adhesives - doubt it'll be cheap though and expect there's always a chance it (damp) will find a way around it expecially if you already getting pools of water.....

Could it be condensation from other work- plastering, paper stripping etc? could check by sealing a small pane of glass to the concrete (silicone, gaffertape, gorilla glue) and keep checking - if it gets condenstaion under the glass (on the floor side) then you have penetrating damp through the slab, if not it's someat else......

hope it helps

Reply to
jim

I believe there are some epoxy based liquid applied membranes about - I've seem them on various "oak floor" websites usually next to adhesives - doubt it'll be cheap though and expect there's always a chance it (damp) will find a way around it expecially if you already getting pools of water.....

Could it be condensation from other work- plastering, paper stripping etc? could check by sealing a small pane of glass to the concrete (silicone, gaffertape, gorilla glue) and keep checking - if it gets condenstaion under the glass (on the floor side) then you have penetrating damp through the slab, if not it's someat else......

hope it helps

Reply to
jim

I believe there are some epoxy based liquid applied membranes about - I've seem them on various "oak floor" websites usually next to adhesives - doubt it'll be cheap though and expect there's always a chance it (damp) will find a way around it expecially if you already getting pools of water.....

Could it be condensation from other work- plastering, paper stripping etc? could check by sealing a small pane of glass to the concrete (silicone, gaffertape, gorilla glue) and keep checking - if it gets condenstaion under the glass (on the floor side) then you have penetrating damp through the slab, if not it's someat else......

hope it helps

Reply to
jim

For a paint-on solution I'd use an SBR bonding agent. Feb do it (Febond?), so it's available at most decent BMs. Although primarily designed to mix into cement based screeds, it works well as a standalone sealer. Not cheap, but it's the closest thing to a waterproofer that can be applied to damp surfaces

Reply to
Stuart Noble

For an SBR slurry look at

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and follow the "tanking" link to Heydi system and K11. There is also a promo video from the home page.

PeterK

Reply to
PeterK

Dear RD It IS condenstation - putting a membrane on a suspect concrete floor is the test for a failed dpc Cure is as suggested - a chemical dpm on the surface prior to fixing new floor Suggest an application of Feb first then (belt and braces) bituthene

use CCA (tanalith) battens Chris

Reply to
mail

thinking further the next issue I can see is how are you going to fix the battens after you have damproofed? could you forget them and just float the floor (boards?) on top of the insulation?

Jim

Reply to
jim

Thanks to everyone who has replied so far. I'm looking into the Febond product and also another called Stopgap F75 which is 2-part epoxy - works out around =A360 for 15sq/m. Jim - as you rightly point out, I can't do this and then screw battens to the slab - so my plan is to screw battens to the wall round the perimeter of the room, and screw the ends of the floor battens to those - laying Kingspan between them so there shouldn't be too much of an issue with stability. I'll probably put standard dpm under the battens as well to reduce any abrasion of the new surface.

R.

Reply to
Reuben_D

Well give it a whirl but I'd still question the battens as at say 4m long X 50mm only fixed at either end they aren't going to offer much in the way of *vertical* restraint.. Horizontally, they'll presumably be wedged in by kingspan so may be better, but I presume you want battens to fix *down* onto to restrain the flooring and resist warp etc??

What are you putting down ?

I would reconsider the possibility that the whole lot will be vulnerable to movement (either seasonal or not), and/or *chatter* against the concrete - when you have the housewarming party :>)

hope it helps Jim

Reply to
jim

Jim

I'll be putting down either boards or laminate. Can't really think of a better option to secure the battens since I can't go through the dpm

- I'm open to ideas. The battens run across the room, so will be just under 3m.

R.

Reply to
Reuben_D

Hi well you could easily float the laminate on the kingspan - i mean you can walk on kingpan (in socks!) and as long as it's supported (by in your case concrete) nothing will happen to it.

For *real* wood (not chipboard or engineered wood which can also float quite happily) then not sure what to suggest altho I'm sure I've seen ads for *real oak* etc that can be floated.....

cheers Jim

Reply to
jim

I would definitely go for the floating floor. My place has floating floors (T&G chipboard panels glued together) on expanded polystyrene which is a lot more flexible than Kingspan. If the laminate being used is that flexible and there will not be height issues, put a floating chipboard layer first, then the laminate (unfixed) on top of it

Reply to
Tony Bryer

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