DPC covered by mortar

[Graham Jones]

Hello,

The DPC in the outer wall of my cavity wall house is about three courses up but is only visible in a few places, elsewhere it is hidden by mortar and looks as though it was initally built this way.

But I was under the impression that the DPC (which seems to be some type of bitumen) should not be bridged in any way. So how does such a construction prevent rising damp?

I'm not worried as we have never suffered any damp problems, but it would be interesting to know how this is supposed to work.

Also how come some houses suffer from rising damp and others don't? All the bricks below the DPC on my house look dry, so why is this? Why is the damp not coming up the earth?

Thanks,

Graham

[Jim K]

[Jim K]

a possibility of a touch of damp in an external leaf of a cavity wall? who gives?

your cavity wall construction will be doing most of the work esp the inner leaf and associated dpc.

its summer; *you* probly have footings in dry ground; what damp there is is evaporating from the bricks' surfaces before you can see it;.......insert more here.....

Cheers Jim K

[NT]

normal and not a problem

the main features that prevent it are not the dpc. The dpc catches the last tiny percentage that would otherwise suffer. If its only the outer few mmm where damp could bridge, it just evaporates off.

More to it than one simple post will adress.

NT

[Graham Jones]

Thanks NT.

My problem is that a lack of knowledge causes me great fear!