'Dutch' tanking method

[Jocelyn]

Again connected with our 'new' neighbours, Tanking apparently is necessary in the aforesaid ( see windows thread). I learnt with interest, that tanking will be carried out in the normal way, but that the cementitious wall will have a gap between it and the wall so that the water will be pumped away to evaporate taking about 6 months to dry out the offending area without water being pushed elsewhere-------- explain please so that I can judge for myself......

 

[Penners]

Is the far side of that building set into the hillside, Jocelyn? If so, then I reckon that's more likely to be the wall that will be tanked, rather than on your side - doesn't the land fall away down to your garden on your side?

I'm a million miles from being an expert on this subject, but the idea of tanking being a separate wall, with an air gap between it and the damp wall, sounds a bit weird. If an air gap is needed to dry out the wall, why not just use a dry lining?

Has the building got any land on its far side? If so, I wonder why they won't simply dig a trench with a supporting wall, in order to hold the soil away from that wall?

Or have I totally misunderstood?

 

[Jocelyn]

Yes it is set into a hillside on the other side from our garden.

Tanking is their business, not mine, but I am really curious about the method since I have never heard of it before. 'Never too late to learn'!

 

[Penners]

The only tanking that I've ever come across consists of several layers of rendering and waterproof materials plastered on to the interior of a damp wall - usually when the wall has high soil levels outside.

I've never heard of a system that involves an air gap. But then I'm certainly no expert.

 

[andrew gayton]

vented dry lining stood off the substrate is increasingly common - it allows the wall to function as it normally does without the usual problems associated with cementitious lining applied direct to the substrate.

 

[Penners]

vented dry lining stood off the substrate is increasingly common - it allows the wall to function as it normally does without the usual problems associated with cementitious lining applied direct to the substrate.

But does that count as tanking, Andrew? Jocelyn's original post said

tanking will be carried out in the normal way, but the cementitious wall will have a gap between it and the wall so that the water will be pumped away

Have you come across anything like that?

 

[PC]

The only Dutch damp proofing system that I am aware of is a system known as Schrijver, which is a sort of tube that is inserted into the wall!!!


PC

 

[Penners]

The only Dutch damp proofing system that I am aware of is a system known as Schrijver, which is a sort of tube that is inserted into the wall

And which seems to be regarded with some scepticism by those who know about these things.

 

[Paul Hopper]

PC and Penners

Years ago I experienced a system of fireclay type pipes inserted in stone and rubble walls, I think it was the Peter Cox system, The wall was opened up a little and the fireclay pipe inserted at an ange and packed with silver sand, outer stone relaid and re pointed.We have a listed cottage in the village with these, and in certain conditions these do indeed seem to weep. We tried some here but to be honest I do not think they do much.but then we only have smallish sections of stone and rubble under the Sole Plate.
I would truly be interested in Matt Greens opinion on this, hopefully he will post a comment or two.

Paul

 

[Jocelyn]

Sounds to me as though it's really just tanking in disguise--- oh well, thanks folks, I was really hoping for a breakthrough in the world of damp treatment.

 

[tony]

tanking that i have come across involves a primer painted onto the exterior of the building, then a waterproof tar like adhesive, then thick rubber/plastic sheeting stuck to wall with all joins given a good overlap.

backfilled carefully with round stones for extra drainage.

only seen this done on a building when i was installing some electrical work, so please allow for some give and take, didnt have the time to stand and watch them all day.

best regards

tony