Rising damp

canaldumidi

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.

damp meters measure electrical conductivity between the two pins. This could be caused by damp,or by any other substance that conducts electricity. On wood they work fine.

Assuming there IS damp though, you need a better idea of where it's coming from. What is outside the walls at those points? Photos?

daveyjp

aoleks said:

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.

Indeed they are different, but both are moisture.  Victorians also cooked and dried clothes, but the properties had open fires and were leaky so the moisture dried out.

Same with penetrating damp.  The walls wicked moisture, but the nature of the building construction meant it was never a problem as it dried before it became an issue and knowledge of the problems of living in damp properties were not understood.

Over the years knowledge develops and construction techniques develop to mitigate the problems of living in damp properties.

stuart45

Most of the materials used in construction contain a certain amount of moisture. It's when it becomes excessive that it's a problem. 
Condensation can be a cause of excessive damp, as can penetrating damp or other things.. 

Alfster

Don’t go near a damp proofing company with a barge pole for a period home. What they will do will make no difference at all. Period properties can be very dry if you understand them. My cottage was built in 1820 and it’s got no damp issues. It HAS had damp issues but all damp issues ALWAYS have a cause and a cure. You need to find why you have this damp issue then fix is accordingly. Damp proof ‘specialists’ have the same cure for every issue and it doesn’t even cure the problem especially in period properties. Here are some potential reasons:

> Indoor humidity levels too high - get a cheap humidistat on Amazon and check your levels. Good ventilation and/or a dehumidifier could fix this instantly.
> check external renders, plasters and paints on the damp area. Old buildings are built from materials that allow a lot of water vapour movements across them. Modern renders and plasters don’t so the water gets trapped and condenses. 

> check outdoor ground levels are not too high. They should be below the indoor floor level. 

If you don’t want the hassle of educating yourself on period properties you can get damp surveys from a period property specialists such as heritage house. Companies like these understand old buildings and will not only identify the cause of your damp but tell you how to fix it. 

A friend of mine had a Victorian house which had some much damp on the walls it had thick black mould on it. The outdoor ground levels were so high they completely covered the floor vents so that they were under the ground! After digging down and lowering the ground level the wall dries out in a week. This took half a day and was free compared to the £8000 the damp proofing company charged her. 

Damp injections can have their place but that never in a period home. 

Woolsery

Alfster said:

Don’t go near a damp proofing company with a barge pole for a period home. What they will do will make no difference at all. Period properties can be very dry if you understand them. My cottage was built in 1820 and it’s got no damp issues. It HAS had damp issues but all damp issues ALWAYS have a cause and a cure. You need to find why you have this damp issue then fix is accordingly. Damp proof ‘specialists’ have the same cure for every issue and it doesn’t even cure the problem especially in period properties. Here are some potential reasons:

> Indoor humidity levels too high - get a cheap humidistat on Amazon and check your levels. Good ventilation and/or a dehumidifier could fix this instantly.
> check external renders, plasters and paints on the damp area. Old buildings are built from materials that allow a lot of water vapour movements across them. Modern renders and plasters don’t so the water gets trapped and condenses. 

> check outdoor ground levels are not too high. They should be below the indoor floor level. 

If you don’t want the hassle of educating yourself on period properties you can get damp surveys from a period property specialists such as heritage house. Companies like these understand old buildings and will not only identify the cause of your damp but tell you how to fix it. 

A friend of mine had a Victorian house which had some much damp on the walls it had thick black mould on it. The outdoor ground levels were so high they completely covered the floor vents so that they were under the ground! After digging down and lowering the ground level the wall dries out in a week. This took half a day and was free compared to the £8000 the damp proofing company charged her. 

Damp injections can have their place but that never in a period home. 

Before you write a long screed on an old post it's best to check out the behaviour of the OP. This one hasn't been back to the thread since 90mins after they posted a month ago!

Alfster

Woolsery said:

Alfster said:

Don’t go near a damp proofing company with a barge pole for a period home. What they will do will make no difference at all. Period properties can be very dry if you understand them. My cottage was built in 1820 and it’s got no damp issues. It HAS had damp issues but all damp issues ALWAYS have a cause and a cure. You need to find why you have this damp issue then fix is accordingly. Damp proof ‘specialists’ have the same cure for every issue and it doesn’t even cure the problem especially in period properties. Here are some potential reasons:

> Indoor humidity levels too high - get a cheap humidistat on Amazon and check your levels. Good ventilation and/or a dehumidifier could fix this instantly.
> check external renders, plasters and paints on the damp area. Old buildings are built from materials that allow a lot of water vapour movements across them. Modern renders and plasters don’t so the water gets trapped and condenses. 

> check outdoor ground levels are not too high. They should be below the indoor floor level. 

If you don’t want the hassle of educating yourself on period properties you can get damp surveys from a period property specialists such as heritage house. Companies like these understand old buildings and will not only identify the cause of your damp but tell you how to fix it. 

A friend of mine had a Victorian house which had some much damp on the walls it had thick black mould on it. The outdoor ground levels were so high they completely covered the floor vents so that they were under the ground! After digging down and lowering the ground level the wall dries out in a week. This took half a day and was free compared to the £8000 the damp proofing company charged her. 

Damp injections can have their place but that never in a period home. 

Before you write a long screed on an old post it's best to check out the behaviour of the OP. This one hasn't been back to the thread since 90mins after they posted a month ago!

Yes I know but this will benefit anyone who reads this post from now onward? Whenever I search forums for info/answers some
of the posts are decades old. It’s about benefiting the forum not just the OP. 

Alfster

stuart45 said:

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.

I don’t think you can extrapolate this result linearly. Rising damp is real but seldom the cause of the damp the OP is talking about in period homes unless it’s sitting in a lagoon 24/7 like Venice as you mention. Even in Venice the average rising damp level in buildings is 1.5m and some these buildings are 800 years old:

Venice is a fascinating example of rising damp. The rising damp itself directly isn’t really the cause of decay; it’s the evaporation of that water out of the masonry and the remaining salts that wreck the building. A sad story for such an incredible city. 

Woolsery

Alfster said:

Woolsery said:

Alfster said:

Don’t go near a damp proofing company with a barge pole for a period home. What they will do will make no difference at all. Period properties can be very dry if you understand them. My cottage was built in 1820 and it’s got no damp issues. It HAS had damp issues but all damp issues ALWAYS have a cause and a cure. You need to find why you have this damp issue then fix is accordingly. Damp proof ‘specialists’ have the same cure for every issue and it doesn’t even cure the problem especially in period properties. Here are some potential reasons:

> Indoor humidity levels too high - get a cheap humidistat on Amazon and check your levels. Good ventilation and/or a dehumidifier could fix this instantly.
> check external renders, plasters and paints on the damp area. Old buildings are built from materials that allow a lot of water vapour movements across them. Modern renders and plasters don’t so the water gets trapped and condenses. 

> check outdoor ground levels are not too high. They should be below the indoor floor level. 

If you don’t want the hassle of educating yourself on period properties you can get damp surveys from a period property specialists such as heritage house. Companies like these understand old buildings and will not only identify the cause of your damp but tell you how to fix it. 

A friend of mine had a Victorian house which had some much damp on the walls it had thick black mould on it. The outdoor ground levels were so high they completely covered the floor vents so that they were under the ground! After digging down and lowering the ground level the wall dries out in a week. This took half a day and was free compared to the £8000 the damp proofing company charged her. 

Damp injections can have their place but that never in a period home. 

Before you write a long screed on an old post it's best to check out the behaviour of the OP. This one hasn't been back to the thread since 90mins after they posted a month ago!

Yes I know but this will benefit anyone who reads this post from now onward? Whenever I search forums for info/answers some
of the posts are decades old. It’s about benefiting the forum not just the OP. 

Agreed, but there's almost as many rising damps on MSE as there were with Leonard Rossiter! Perhaps it should be a sticky?

Alfster

Woolsery said:

Alfster said:

Woolsery said:

Alfster said:

Don’t go near a damp proofing company with a barge pole for a period home. What they will do will make no difference at all. Period properties can be very dry if you understand them. My cottage was built in 1820 and it’s got no damp issues. It HAS had damp issues but all damp issues ALWAYS have a cause and a cure. You need to find why you have this damp issue then fix is accordingly. Damp proof ‘specialists’ have the same cure for every issue and it doesn’t even cure the problem especially in period properties. Here are some potential reasons:

> Indoor humidity levels too high - get a cheap humidistat on Amazon and check your levels. Good ventilation and/or a dehumidifier could fix this instantly.
> check external renders, plasters and paints on the damp area. Old buildings are built from materials that allow a lot of water vapour movements across them. Modern renders and plasters don’t so the water gets trapped and condenses. 

> check outdoor ground levels are not too high. They should be below the indoor floor level. 

If you don’t want the hassle of educating yourself on period properties you can get damp surveys from a period property specialists such as heritage house. Companies like these understand old buildings and will not only identify the cause of your damp but tell you how to fix it. 

A friend of mine had a Victorian house which had some much damp on the walls it had thick black mould on it. The outdoor ground levels were so high they completely covered the floor vents so that they were under the ground! After digging down and lowering the ground level the wall dries out in a week. This took half a day and was free compared to the £8000 the damp proofing company charged her. 

Damp injections can have their place but that never in a period home. 

Before you write a long screed on an old post it's best to check out the behaviour of the OP. This one hasn't been back to the thread since 90mins after they posted a month ago!

Yes I know but this will benefit anyone who reads this post from now onward? Whenever I search forums for info/answers some
of the posts are decades old. It’s about benefiting the forum not just the OP. 

Agreed, but there's almost as many rising damps on MSE as there were with Leonard Rossiter! Perhaps it should be a sticky?

Good idea 👍 

stuart45

Alfster said:

stuart45 said:

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.

I don’t think you can extrapolate this result linearly. Rising damp is real but seldom the cause of the damp the OP is talking about in period homes unless it’s sitting in a lagoon 24/7 like Venice as you mention. Even in Venice the average rising damp level in buildings is 1.5m and some these buildings are 800 years old:

Venice is a fascinating example of rising damp. The rising damp itself directly isn’t really the cause of decay; it’s the evaporation of that water out of the masonry and the remaining salts that wreck the building. A sad story for such an incredible city. 

I wasn't really serious about the 1.38 miles. Usually stops around a mile.
Jeff Howell was probably one of the first to study rising damp when he built a load of brick piers and stood then in water. He couldn't see any signs of rising damp and since then has written the book about the rising damp myth. 
However if you stand a brick pier in water the change in the pore structure of the mortar bed is different to the brick and this is thought to slow down the rise and allow the moisture to evaporate before it goes any further.
You normally find that moisture will go up the wall though the render or plaster as the pore structure is the same. There used to be a damp problem when membranes were first used under the slabs and the bricklayers used to cut them flush with the inner wall. This left a weak spot between the DPC and the DPM which allowed moisture to creep up the plaster.