tanking?

[junglejim01]

Hi, i wonder if anyone can suggest a good paint on tanking system i can use in an area that is 1ft below the external ground level and suffering damp.

I'm pretty sure the damp is penetrating through and despite applying a coat of Wykamol Aquastop the area is still wet to touch. Any help very much appreciated

 

[Norcon]

Paint won't stop it.
Dig down from the outside and lay drainage. Then fit the tanking membrane on the outside.
But not paint!

 

[junglejim01]

Thanks for the reply. maybe i wasn't clear enough, this wasn't paint, but a cementious tanking system: http://www.wykamol.com/services/damp-proofing/tanking-products/aquastop-tanking-system.html

I know that the ideal is to dig down outside but was hoping to avoid this if possible. Thanks again[/url]

 

[freddiemercurystwin]

The trouble with that type of tanking is that it requires meticulous preparation and application and even then it will not cope where the hydrostatic pressure is high, despite that it says it will. It just gets blown off the wall.

You need to establish why and how the water is penetrating and if that cannot be prevented then find a more robust method of keeping it out with (as mentioned) either tanking on the outside or a membrane system on the inside. But if applying to the inside it either needs to be a drained membrane system or if a conventional membrane it needs to be held in place against the wall with additional masonry skin otherwise (like your render) it will just get blown off the surface and fail. But beware the wall tanking often needs to be taken across the floor too.

 

[junglejim01]

thanks, that's interesting as there are a lot of paint on cementious products claiming to be good for basement tanking. Does anyone have any experiences with these?

I'm thinking of getting the drainage sorted, i just hope this will solve the problem once and for all.

 

[Norcon]

We tank underground using this method... With benonite or water bar at the joints.
It rarely fails..

 

[junglejim01]

A builder is looking at sorting out the drainage outside and has suggested Aco drainage with membrane against the wall. Does anyone have thoughts on this?

 

[freddiemercurystwin]

Any pics of the outside? What's the wall/floor construction? Anything coming up through the floor anywhere?

 

[junglejim01]

Thanks i'll see if i can some pics up later. Outside is concrete and raised above internal floor by about 1ft. The wall is victorian brick but below ground is sandstone. Internally, the floor is also concrete i can't see amy moisture coming through the floor, but the damp is most prolific at the base of the wall and does spread along the surface of the floor in a bit (mostly after rain i think).

 

[junglejim01]

i should probably also mention that externally the wall is rendered, so lots of concrete and rendering = recipe for damp! I'm looking for the easiest sound solution. Just started looking into Aco drains, looks like it may be an option but i can't find much on the use of these in areas with penetrating damp. The builder mention fixing a membrane to the wall outside too but all the Aco drains i can see look shallow so i'm still not sure about getting down below the internal ground level.