external wall lining

[Fizzer]

My memory has failed me, I know that I have seen a product to waterproof the outside face of our our walls which are underground, and now I can't find them!

We have a landscaper coming in two weeks to install a french drain at the back of the house, ground levels are 4' over floor level.

I have seen plastic sheet which is corrugated on one side to allow the wall to breath after the drain has been filled, can anyone shed some light on where I might find it?

Thanks

Andy

 

[BMcD]

Is this the sort of thing you had in mind?

http://www.newton-membranes.co.uk/geodrain.htm

 

[Fizzer]

That one seems to require coating the wall with damp proof 'goo', I'm worried that this will prevent the wall from breathing.

 

[CHRIS]

You want something like this

http://www.terram.com/content.php?nID=155;langID=1

or any other geotextile drainage membrane

 

[Fizzer]

that's permiable isn't it? (Or am I being dumb?)

 

[Fizzer]

Ahaaa, found it
http://www.safeguardeurope.com/products/oldroyd_g.php

phew..

 

[BMcD]

Fizzer wrote:

Ahaaa, found it
http://www.safeguardeurope.com/products/oldroyd_g.php

phew..

This also requires coating the wall in "goo" as they are a secondary layer to work in conjunction with a waterproof layer.

Oldroyd ‘Gtx’ is used as
a secondary drainage
layer to protect a
primary waterproofing
system such as: [1]
• DryBase Vapour
Membrane
• Vandex Cemelast
• Vandex BB75E
• Vandex Super

 

[Fizzer]

I think it's recommended but not required, i'll call them up and see what they say (I'm sure they will recommend purchasing goo from them) but I'd be interested to hear what people think about this as I was under the impression that allowing the wall to 'sweat' is a good idea.

Oldroyd Gtx membranes are usually used as a secondary drainage layer to protect a primary waterproofing system

 

[Stephen]

The OP stated outside face of the wall - presumably because during the French Drain works you have exposed the outer face.

Generally damp proofing of a basement, etc is best dealt with fom the exterior, but with an existing basement is rarely possible. The application of an impermeable barrier on the outside face is not the same problem as one on the inner face. However, you need to think it through in case by applying an impermeable surface you could rive moisture elsewhere. That said if you are installing a French Drain, etc the amount of water at the base of the wall should be far less and therefore the risk of water getting in below the bottom level of an externally applied barrier is lower than if there was no French Drain.

Some of the membranes (e.g.Oldroyd, Newton, Delta, Proton, etc) are designed for external use

My first inclination is to use one of these systems on the outer face, even if it includes a greater degree of impereability than might normally be desirable (when dealing with it from the inside). Nonetheless, I would want to think through where moisture might be displaced to.

 

[Fizzer]

Yup, we are digging down to expose the wall (when I say we, I mean our friend - my wife was a little concerned that with a digger I'd knock the house down)

I've been thinking about this a bit. We actually have to buy a 12x2 metre roll which is approx. twice as much as we need. So I'm actually thinking of doubling it up to have drainage gaps on both the earth and wall facing sides.

This would give me a drainage channel for the water, allow the outside face of the wall to breath and also provide the 'primary' layer without using impenetrable goo on the wall.