Where's me damp course?

[Ronob]

I have a 1921 built end terrace house, with a solid brick wall (LBC Rustic brick) no cavity.

I cannot find the DPC! I have scratched away at the pointing in a few different places from ground level to two bricks above floor level - nothing!

The house has no damp there are no external tell-tale plug holes indicating that a chemical DPC has been used so there must be something, shouldn't there?

What is equally odd is that the shared alley - concrete - between me and next door is almost 3 bricks higher than our floor level. Along that alley our house wall has a skin of render, about 10mm thick, and 3 courses high. This rendered 'skirt' is only down the side not at the front or back.

We're on a bit of a hill so the house next to us is 2 maybe 3 courses higher than ours and they had an extension put up where it can be seen that their new DPC is tied into the old brickwork at the same level as the top of their rendered skirt. If that is the same with my house, it would mean the DPC is 6 courses above the floor! Surely incorrect!

My problem is, I am going to be building a short walk that will butt upto the house so need to locate the DPC link in with the walls DPC.

Any ideas as to what I can / should do?

 

[Pigeon85]

Have you tried looking under the ground level, maybe it has been built up in more recent years. If you still cannot find anything there are ways of protecting it before you do the work

 

[Ronob]

Underground DPC? Now there's a concept I hadn't thought of!

I can't easily check that as we've got concrete around all sides.

I'm thinking of tying in with one of those aluminium strips that attach to the house wall with like arms that fold down over the adjoining wall between the courses, but put a strip of DPC membrane between the wall and the fixing strip and spray lots of sealant on the wall too

It might not conform with current regs but nor does no visible DPC!!!

 

[^woody^]

My problem is, I am going to be building a short walk that will butt upto the house so need to locate the DPC link in with the walls DPC.

If you mean wall, then you should not be linking to the house DPC or tying the wall to the house.

Run a vertical DPC up the abutment and seal with flexible mastic

 

[Pigeon85]

If it is only a short wall then it wouldn't need to be tied anyway.

I know you could bitumen the outside wall but any damp that exists in the bricks will go inside.

 

[Ronob]

Yeah sorry my phones spell check can be a nightmare, it is a"wall" not a walk I'm building - 1.5m high 4m long.


I think a DPC between the new wall and existing house wall is going to be the best solution. I feel using one of the previously mentioned wall tie things would add stability as it will be just a single brick width with a pillar in the middle and far end.

All advice / ideas welcome

 

[^woody^]

Fix a fish tail tie (L shape bracket) at 600 and 1200 high

 

[maltaron]

The chances are that there will not be a damp course in a 1921 house. If there is it could be 2 courses of blue bricks or possible hard red engineering bricks. It could possibly have a slate DPC but definately not felt or plastic. However, if as you say, there is no damp, then dont worry about it.

 

[Ronob]

The chances are that there will not be a damp course in a 1921 house. If there is it could be 2 courses of blue bricks or possible hard red engineering bricks. It could possibly have a slate DPC but definately not felt or plastic. However, if as you say, there is no damp, then dont worry about it.

Yes it was slate I was expecting, I knew there were no engineer/blue bricks. It just seems odd that we've no damp - maybe the old ways are the best! I'd be interested to know how damp is controlled in such a build

 

[stuart45]

In theory all houses built since the Public Health Act around 1875 should have a DPC, but this is not always the case.
Old houses without a DPC had lime plaster inside which allowed the walls to breathe and allowed moisture to escape.

 

[Nige F]

Slate dpc with the face edge kept back and the pointing covering - form over function , and rising damp doesn`t esist

 

[Ronob]

I've cut back about 30mm into the pointing. I wondered if the slate is only present over the inner brick - seems a bit skin flint to do that though