Damp Wall Sealing:

[Gluestick]

Looking for ideas.

My main garage/workshop has an old brick wall which is hard up against the grazing land next door.

Trouble is the land next door is circa 1.75 metres higher and I have penetrating damp at the bottom of the wall.

The prevous owner has applied a cement plinth to circa 1.5 metres, however I now need to seal this wall in to prevent the workshop becoming over-damp

I shall put in some drainage at the very bottom but need some form of sealing product to paint over the whole wall.

Any ideas for a French product?

Later on, I intend to expand the space by adding an extension building: the same wall (which is retaining) goes along the whole way, thus I will need to treat this further along as well at some time.

 

[Framboise]

We used this black tar stuff painted onto the walls throughout our house as it was riddled with damp downstairs.   Plaster was rmoved up to 3 feet, painted with pitch and replastered -  not had problem since.  I assume you could use this technique on your problem area.

We bought this stuff in England but I would presume you can get it it France.  Its an old fashioned, tried & tested system to eliminate damp although  it might also be an idea to clear the soil and plants away from the wall itself to allow the air through. 

[Gluestick]

Thanks for that, Raspberry. (I love 'em BTW! [:D]).

I cannot do anything on the other side of the wall as it's someone elses's land.

The core problem is that our house in on a hill and each plot has been terraced, so the water table flows from top to bottom.

Thus all I must do is seal the wall in on my side (interior of the dependance) to above the adjacent land level, inject a chemical DPC (to prevent the damp rising)  and install drainage at the bottom, vented to the outside.

I don't want to go to the expense of fully tanking a workshop (!!), but need some resin or similar coating to seal the wall and prevent the ingress of damp along the floor.

 

[Framboise]

Another suggestion - what about dry lining the inside of the building?

You put a thin membrane of polystyrene on the wall then batten, followed by plasterboard over the top.  Similar technque to lining a roof I guess.  Hubby did this on the workshop here in UK and has no problems with damp.  Otherwise there are some sealants that you paint on that might ease the problem for you.

Being on a terrace won't help of course.   Our house is called Le Gue yet theres no sign of a ford nearby which baffled us - until the neighbours metioned that "the stream goes under your house.....".  Still, its been there for more than 100 years and has only been inhabited for a fraction of that time, let alone had central heating installed, so damp was bound to be in situ wasn't it?   We still have a little residual damp popping up in a couple of places, but then its bound to as the chauffage is off more than its on because we are still in UK for most part, moreover our house here in UK has just as much of a problem with damp and its only 60 years old!.

Hope you solve your problem!

[Gluestick]

Thanks again Raspberry!

I am loath at this stage to think in terms of impermeable membranes, as I would then have to run it around the brick piers front and back (which serve as the door posts). If not then the damp simply emerges where the membrane leaves off!

I have found some stuff in the UK; resin paint which forms an impermeable barrier which should do.

I am sure however that there is something used in France for sealing cellars and that we have discussed it on here previously: a search however failed to find it!

By Murphy's law I want to place new benching and cupboards (Steel) on this wall! Can't do that until I solve the damp ingress!

 

[Framboise]

I will study the Bricodepot catalogue we have here to see if there is anything that might do the trick then post for you.  Hubby says that you can usually find something similar to what he would use here, so we will see!

[Bugsy]

Purely from an engineering point of view it would surely make sense to treat the outside of the wall rather than the inside. I doubt whether any product exists that will effectively bond onto a wet surface. I think I'd have a word with the owner of the field with a request to remove the soil, treat the wall and then make good. You could then sneak in some drainage pipework to divert the water around your building...[:)]

[Framboise]

And, here you go!   In the Brico Depot catalogue page 286, you have Traitment des Caves - the stuff you referred to that you paint on, as well as another one alongside.   These look a bit expensive to me so is is possible you could buy it here in UK and ship it over?   We buy all this type of stuff here usually 'cos hubby gets trade discounts, hence our vehicles are normally clanking along the well-worn roadways to 61 loaded with paint etc.   Maybe your next visiting relatives could buy it as a "Thankyou" gift???

Bugbear is right though cos the remaining problem is bad drainage, to which the longterm cure is putting ample drainage alongside the building like the caniveaux on page 14 of Bricodepot catalogue, if this is possible.  Its a lot more work as you would probably have to do both tasks, but then Hubby had to construct a large soakaway from our house just to drain the roof water away, and now done we don't have the amount of trouble that we used to.  In the long run it may be worth the extra effort.  

Am I turning into a DIY fiend??   This is worrying! 

Addendum!     Just read Ron's post.    We have used diluted PVA glue (Unibond) as a sealant under floor tiles and on new plasterboard before painting/papering.  Is his the stuff Ron means?

[Ron Avery]

"Purely from an engineering point of view it would surely make sense to treat the outside of the wall rather than the inside"

 I think the OP made it clear that was not an option Gary, he lives on a hill that has a terraced field, so a lot of earth moving would be necessary and he does not own the land.

I'm surprised that none of the builders on here have answered this, it a commom problem with stone walls and caves near fields and backing onto earth ramps up to barns etc.  You can live with it as the damp normally subsides in summer, though not this one I suspect,  or put a waterproofing solution on the inside walls, like the Ronseal product in the UK.  If you go into M. Bricolage you will find a waterproofing paint that seals walls in the specialist paints section, it is not cheap and you are probably looking at + 40€  for 2 litres.  You could also try a PVC solution like the one applied to floors pre-tiling.

[jc]

There are rubberized paints,ones with glassfibre and resin in and even PVA but I think all of these would only be a temporary solution-even if it stops water coming thro' the wall directly it will come under or round in time.As already said,tho' apparently not possible,the only permanent solution is to treat it from the outside.

[Bugsy]

Which is why I suggested that he talk to the owner of the field. There would be earth removal and extra cost involved, but it would cure the problem where simply painting something on the inside of an already damp wall would give no such guarantee. You only have to look at new-builds to see that walls to be buried are treated on the outside before being back-filled. JCB and a driver costs in France (certainly around here) are very reasonable .

[Gluestick]

Lots of good ideas and assistance here, folks. Many thanks.

Actually Gary, the people who own the field (it's very big and expands at the back: used as cow pasture) are good friends: however it is part of an estate and is to be sold, so I will chat it over with them soon!

Actually back in the UK now, for a bit and back to boring work! [:(]

Field at back and freezing guest!

[IMG]http://i74.photobucket.com/albums/i278/Michaeleff/FelthamsHouse010.jpg[/IMG]

 

Old wall as it runs back from dependance. The old wall is painted white and behind the small workshop.

[IMG]http://i74.photobucket.com/albums/i278/Michaeleff/PicturesHouseFrance0045.jpg[/IMG]

 

 

[bejay]

I had a very similar problem many years ago where a room I needed to convert to a bedroom had earth built up to form a terrace by a neighbour. This room had a cavity wall so I removed the lower half of the inner leaf put an injected dampcourse in at a higher level and installed a vertical polythene DPM linked in to the inner leaf damp course. Then rebuilt and plastered the inner leaf . In twenty years there has never been the least sign of any damp penetration.

The question is can you afford to lose about 4 -5 inches of your workshop floor area for a truly permanent solution?

bj

[Gluestick]

I could in fact "Tank" it, but the cost is not worth it!

By using the latest tanking solutions I would only lose about 60 cms of width.

I shall firstly speak to my friends about the pasture next door and then  look at inserting ceramic plugs along the bottom, feeding into a drain to outside and therafter, seal the wall to just above ground level with the resin stuff and then inject a DPC above that.

This should drive the damp to the front and back piers and I can live with that!

Strangely, the most obvious place for damp ingress is the join between the floor and the wall.

 

[bejay]

[quote user="Gluestick"]

By using the latest tanking solutions I would only lose about 60 cms of width.

[/quote]

Sounds like a lot to me but then I may well have misunderstood your point.

bj

 

[Gluestick]

Not at all bj.

It's Monday!

I meant, of course, 16 cms..................[8-)]

I think I'll buy some scuba kit instead! [:D]