L3 Survey & Damp Proofers advise Chimney Breast Damp - Victorian Mid Terrace

[stuart45]

What I find amazing (or depressing, depending on your own perspective) is why the issue of rising damp remains so contentious in our scientific age. We can put a man on the moon but we seem to have no societal consensus about rising damp, which has given rise to all manner of 'cures'. Even building control legislation is complicit by requiring DPCs to be part of new buildings. It's all very strange and seems to be more of a faith issue than a scientific one.

Part of the reason for the lack of proper research is down to lack of funding. Sheffield Uni did receive a certain amount a few years back, and there was a 4 year study resulting in a 400 odd page report. The end result was that rising damp does exist.
The Dutch government handed a load of cash to one of their Unis, although according to Peter Ward Holland doesn't have any rising damp or DPC's.
There was also a study done by Ralph Burkenshaw known as the Camberwell Pier.
When some experts cover themselves by saying true rising damp is extremely rare, they never seem to explain the exact reasons why it occurs in those rare occasions.

 

[IHateDamp]

When some experts cover themselves by saying true rising damp is extremely rare, they never seem to explain the exact reasons why it occurs in those rare occasions.

I wondered if they say this because if they said it doesn't exist they would never hear the end of it from the damp industry lobby

 

[stuart45]

I wondered if they say this because if they said it doesn't exist they would never hear the end of it from the damp industry lobby

Possibly, but if you claim to be an expert, you should expect someone to ask you what conditions are required for true rising damp to occur.
The findings from Sheffield Uni were basically that the sorptivity of old highly absorbent bricks built in lime mortar was enough to stop damp rising. However, after many years, in certain soils, salts getting into the pores affected this, and moisture was able to move up the wall.
Peter Ward is probably the only well known person on the internet who says the rising damp is a total myth, and can't happen anywhere. He used to be on this forum years ago, although back then he said it was theoretically possible. To be fair to him, he has probably had the biggest effect on the damp proofing industry in the last 10 years, although he'd probably do better if he cut out all the B/S such as rising damp was invented in 1962, and the UK is the only place in the world with a rising damp issue, and chemical injection as a solution. As @Cubist said, it's always worth questioning information. Even Rosalind Artis of the Scotish Lime Centre in recommending his book says how he explains how we are the only country in the world with this issue. A bit of research would show that rising damp and chemical injection is used all over Europe, and other parts of the world.
It doesn't mean that it's the correct method because of this, but it's better to get your facts right, as often you get found out in time.

 

[Matt Green]

What I find amazing (or depressing, depending on your own perspective) is why the issue of rising damp remains so contentious in our scientific age.

It would help if there was an agreed definition for a start. Rising damp is:

1) capillary action in brickwork (PCA)
2) an outrageously rare phenomenon where capillary action occurs with no other source of obvious water penetration into the wall (HE, Ridout, H+R, EBC etc)
3) not possible (that guy)

When some experts cover themselves by saying true rising damp is extremely rare, they never seem to explain the exact reasons why it occurs in those rare occasions.

I've surveyed a lot of buildings. I said 99.99% of times in the post above and if I surveyed 10000 more buildings there might be one where I was stumped by the cause. I'm not hedging, but giving it a 1 in in 10000 chance seems fine to me. I've had my opinion changed before by this forum (see @Zebra 's wooden post with furniture beetle damage), it's how science works.

High water tables, maybe? There are allegedly BRE case studies out there but I have never seen one.

There are so many variables to consider in old buildings that coming to any definitive position risks taking a faith stance. I've seen water rise in walls and have the core sample w/w results that show it and the salt content. I've never seen that happen without a cause that could be addressed with good building conservation practices.

And I still think the topic is boring.


M.

 

[stuart45]

There were cases of allegedly rising damp in houses built in the late 60's, 70's, early 80's. It was when we used to cut through the DPM with the trowel flush between the slab and inner skin, instead of bending it over the inner skin. It was found in a few houses that damp was getting through the slight gap between the DPC and DPM. It was not the majority of houses that were affected, but enough for it to be an issue. Most footings back then were either LBC commons, or blocks. Above DPC, commons or Thermalite blocks.