Brickwork steps and the damp-proof course

[tabbypurr]

Bridging the dpc occurs inside the wall. Those are just too high ground levels.

NT

[tabbypurr]

1. BRE testing found that only very soft brick & sandy lime mortar walls were prone to any RD at all.
2. Chimneys sometimes get salt deposition from fuel residues, leaks or spills.
3. Historic animal pee is sometimes a cause too in very old houses.
4. Having a lake under your house is going to dump a whole lot of water vapour into the air and chill the base of the walls.
5. Rising damp scams are widespread
6. Even if your property did have RD, that does not in any way invalidate what I said, namely that lack of DPC does not normally produce RD.

Don't take my word for a thing. Stephen Boniface, former chairman of the construction arm of the Royal Institution of Chartered Surveyors (RICS), has told the institute?s 40,000 members that ?true rising damp? is a myth and chemically injected damp-proof courses (DPC) are ?a complete waste of money?.

NT

[Vir Campestris]

That may be true in the vast majority of houses - but not all.

We had persistent problems with salts crystallising out on the lower parts of our walls. We've had the plaster replaced in parts of it (with lime plaster BTW) and during the work we found area where the timber soleplate had succumbed to rot. Including one place where half the upstairs floors were leaning on a beam that was supported by a post which was dangling in the air :( that explained the bulges in those walls!

OTOH this is a 300yo timber framed building on a brick plinth. It's not typical.

We do now have a chemical DPC in the brick plinth. Things are now OK; we'll know in a hundred years or so whether this is a long term fix.

Andy

[Jonathan]

I just used some spare slates, that has been good for over ten years.

Jonathan

[alan_m]

It was and still is a scam because the existing DPC hasn't failed.

The whole injection industry now exits because 3 or 4 decades ago it was almost impossible to get a mortgage without a damp survey (and in some areas a woodworm survey). The surveyors (salesmen) who then came around to check always found rising damp.

[Bert Coules]

Nice idea; thanks.

[tabbypurr]

opinion is divided on that

that has generally been dxed as RD, but there are other known causes

Does rotting wood release salts?

[Vir Campestris]

The walls with the salt problems weren't the ones with the rot.

BTW - I don't know what the salt is. It's isn't sodium chloride.

Andy

[tabbypurr]

Water soluble salts tend to migrate outwards through the wall as water moves out, and end up washed away by the rain. What gets left on interiors are salts that were water soluble, but no longer are... the chemists might like to comment further.

NT

[The Natural Philosopher]

sodium carbonate usually or calcium carbonate