Rising damp

woody7777

My son has bought a Victorian terrace that had rising damp identified in the walls by the surveyor from the damp proofing company that was recommended from the surveyor.
The remedy is to remove the plaster a metre up and replaster with a damp proof plaster and also drill the walls.
I have read on the internet that rising damp does not exist and that this is unnecessary work. Is this correct?

mabbit

If you go to a butcher and ask what to buy for dinner, you will get meat.

If you go to a greengrocer and ask the same question, you will get vegetables.

If you go to a damp proofing company and ask for advice, you will get something similar to what you were offered.


Get independent advice, possibly from a builder who has previously worked on houses in your area.

You should be looking at drainage (eg damaged gulley drains), and similar ground issues before drilling walls.

The water must be coming from somewhere...best to remove the source of the damp

babyblade41

pretty much... Damp comes from ingress of water, find out where that comes from ie, DPC covered, guttering, chimneys etc & problem solved 

Your are being recommended to mask the problem not solve it.

Are any of the skirtings wet ? where abouts is the damp coming from, can you smell the damp ? or is it possible surveyor has measured the damp in the walls with one of those daft damp meters 

jimbog

Yes, it’s a myth

https://www.heritage-house.org/damp-and-condensation/the-fraud-of-rising-damp.html

daveyjp

Victorian houses are damp because they weren't built for modern living.

The damp has probably been an issue since the house was built, but we come along and block up chimneys, fit windows and doors which don't let in a howling gale, cook in kitchens with doors closed, dry clothes indoors, raise external ground with patios, decking etc so the conditions mean the damp can't evaporate.

If you put a wet item into a sealed plastic bag it will never dry out.  We have made Victorian houses into the equivalent of a sealed plastic bag.

woody7777

babyblade41 said:

pretty much... Damp comes from ingress of water, find out where that comes from ie, DPC covered, guttering, chimneys etc & problem solved 

Your are being recommended to mask the problem not solve it.

Are any of the skirtings wet ? where abouts is the damp coming from, can you smell the damp ? or is it possible surveyor has measured the damp in the walls with one of those daft damp meters 

The damp is on the external walls at the front of the house, and also a bit at the back of the house. I think the damp expert used a damp meter on the walls. The damp shows as a few stains about 6 inches above the skirting boards.

aoleks

daveyjp said:

Victorian houses are damp because they weren't built for modern living.

The damp has probably been an issue since the house was built, but we come along and block up chimneys, fit windows and doors which don't let in a howling gale, cook in kitchens with doors closed, dry clothes indoors, raise external ground with patios, decking etc so the conditions mean the damp can't evaporate.

If you put a wet item into a sealed plastic bag it will never dry out.  We have made Victorian houses into the equivalent of a sealed plastic bag.

Damp and condensation are two different things. If it is indeed damp, then you need to sort out the cause of the problem (broken DPC, for example) before making good the walls.

Mr.Generous

On a property of that age the damp course was probably a layer off slate under the brick. Long since failed or been bridged, the walls and plaster will draw damp up from the ground. The remedy they suggested is spot on. Plaster off, drill and inject a chemical DPC, then re plaster with a plastering sand / portland cement  / damp proofer mix and it will be done.

Or you can p155 about for years trying all different remedies that won't work.

There are houses with condensation problems and no damp that someone comes along and tries to rip em off with a load of expensive damp work, but there are a lot of older uk properties that have rising damp, and it sounds like you do.

I don't do damp work or sell anything to do with damp. I have no reason to push it. I renovate property and have had to deal with damp a few times. Painting some special paint over it wont do anything. I suspect those who claim it doesn't exist haven't lived in a  house where an internal wall with no plumbing in or above has damp, wallpaper and paint peel, skirting rots, mold appears. When you knock the skirting (and plaster) off you can really smell the damp.

stuart45

jimbog said:

Yes, it’s a myth

https://www.heritage-house.org/damp-and-condensation/the-fraud-of-rising-damp.html

I'm not really convinced by Peter Ward's site. Rising damp was around before 1962. I've got bricklaying text books handed down to me earlier than 62  that talking about rising damp. Also there are other countries that recognize it as a problem. He talks about Holland never using a DPC but I worked with Dutch bricklayers in Belgian years ago that stuck it straight onto the brickwork without bedding it.
European attack on rising damp in buildings (tudelft.nl)
Google rising damp in Venice, although that's an extreme example.
In the USA it's known as wicking.

FreeBear

woody7777 said:

babyblade41 said:

pretty much... Damp comes from ingress of water, find out where that comes from ie, DPC covered, guttering, chimneys etc & problem solved 

Your are being recommended to mask the problem not solve it.

Are any of the skirtings wet ? where abouts is the damp coming from, can you smell the damp ? or is it possible surveyor has measured the damp in the walls with one of those daft damp meters 

The damp is on the external walls at the front of the house, and also a bit at the back of the house. I think the damp expert used a damp meter on the walls. The damp shows as a few stains about 6 inches above the skirting boards.

Some photos of the general outside might provide some clues.

Rising damp does exist, but now where near as common as these PCA surveyors salesmen would have you believe (and why is it always to a height of 1-1.2m regardless of building material...). If there is a DPC at the base of the wall, it is probably being breached somewhere - A DPC does not fail along the full length of a wall. You might get isolated spots where it has cracked which might lead to small damp patches internally. Pumping chemicals in to the wall will do nothing apart from emptying your wallet. Slapping waterproof render/plaster on will mask the problem for a few years until it pops its head up again. You then have to spend more money on further "cures" and fixing any damage caused by the previous treatments.

If you are going to replaster, use a pure lime plaster - It will cope with slightly elevated levels of damp without turning to a mush like a gypsum plaster would. You'd also want to use a clay paint or lime wash over the top to allow the plaster to breath.

stuart45

Out of interest and with nothing better to do now the crickets been rained off I stuck an old brick with a lime bed joint into an inch of water for an hour and it rose about an inch. So by my calcs it would be 1.38 miles in ten years.