Concrete waterproofer

john-306

Friend of mine has a house where you come out the patio doors onto a concrete area about 7ft by 5ft by 1ft? thick, steps lead down to the garden and underneath this 7 x 5 slab of concrete is a storeroom/garden storage area, this as for the last few years been letting in water through the ceiling, there is no spliting /cracking of the above concrete so I can only assume the concrete slab is letting water in through it.
Are there any products available that will totally waterproof this concrete slab and stop water penetrating through, needs to be some type of paint on as its a walk on area, only really found bitumen based and that wont be suitable.
Thanks.

bigdoozer

Yep..... there are a few, but I would expect water to be coming in around the slab (ie wher is joins the other parts) rather than throgh 12" of concrete. Is the side (s) underground, and what are made of? I do have a couple of non-bitumen solutions (nano technology), One in particular is great and can be walked on. Even better if tiles, stones or slabs are added Where R U?

john-306

Can't be 100% certain but nothing visable around slab itself that looks like it will let in water.
All sides are above ground, and the wet covers the whole of the ceiling after rain, at the front is a wooden door and 1 wooden window.
I'm in West Midlands.
Thanks for reply.

Kiran

I agree with bigdoozer, its unlikely to be coming through the concrete slab. Have you/your friend looked at the underside of slab during rain or hosed the slab to see if it can be seen?

Mapei make some very good product which could do solve the problem if it is infact pentrating the slab. I've used this when building a leisure centre swimming pool.

HTH

bigdoozer

I would invest in Liquid Rubber, we use it for concrete tank sealant (from new) and they hold piggy poo, and that is very very bad stuff. It may have to be done under the edges too and possible over 1st couple of bricks, but Kirans ideas is good too, get some ordinary morter dye or food colour and a watering can, make coloured water and pour it on small areas at a time and see if you can find a route... want help, just ask.