Damp proof course advice

[Tevez]

Hello all. I have bought my first home which is an old cottage built around 1800. It has been in the family for generations. It has rubble filled stone walls and I neeed some advice on damp.
It has suffered with damp which we assume was due to poor pointing which has now been redone. I've researched on which route to go for a damp proof course and had 2 companies out to give me a quote. Both have suggested a plastic membrane system needs to be installed, floor to ceiling, then dot and dabbed. I just want some advice on whether this is the best route to go before I part with £3k. So if anyone has had any experience I would appreciate the help.
Thanks.

 

[MikeG]

Hi, and welcome to the forum.

There are some terminological inexactitudes to unravel here before we can resolve your issues.

Firstly, rubble. Any stone walls which aren't made of rectilinear dressed stone are called rubble walls, even if the stones are many feet across. Rubble, in the context of stone walls, isn't the loose mix of small particles and small pebbles which people usually associate with the word. So having a rubble wall doesn't necessarily mean that you have a solid inner and outer skin and a core of loose stuff between.

Secondly, a damp proof course is a horizontal barrier to rising damp in a wall. If there is a vertical element to it then it is a damp membrane, or sometimes a vertical DPC which always terminates at the DPC level (ie some 6 to 18 inches above the ground level). What you seem to be describing is a vapour barrier, to prevent vapour transmission through the wall, and I can't think of any circumstances in which that would be the answer to a damp problem in a stone building. All that a plastic sheet on the inside of a wall can achieve is to prevent vapour from inside getting into the stone, and trapping any moisture from the outside in a pool at the bottom of the wall inside your plasterboard. Neither are any answer to a damp problem.

As an architect I am always very cautious of giving advice without all the facts. Without photos and a section drawn through your building we are all just guessing. However, I would most certainly not recommend that you proceed with the installation of a vapour barrier without some better advice. I advise you to contact a local conservation architect, and most certainly not take the word of your damp companies.

 

[MatthewC]

Hi and welcome.

Mike gives good advice above, to which I would add the following: you don't want to battle with the SYMPTOMS of dampness, you want to tackle the CAUSE. There are a lot of things that could cause dampness in a wall, and a search on this forum might well find them, but from memory they are:

i. Rainwater goods (hoppers, downpipes and gutters blocked or damaged)
ii. Blocked drains (you want them to take water AWAY from the house!)
iii. High external ground levels (you need the external ground to be 6" below the floor inside)
iv. Solid paving up to the wall (causes splashback when it rains, making the base of the wall always wet to a surprising height)

Other odd causes can include a cistern overflow down the wall (sort out the ballcock!), while vegetation growing up the wall doesn't help (ivy might look nice but it's dreadful really). Also, if you are talking about a damp chimney breast, checking the lead flashing on the roof is always a good place to start.

Finally, DPC salesmen are regarded generally here as purveyors of snake oil or other miracle cures - they are in it purely for the money and the last thing you want to do is something which is at best, I suggest, a waste of your money and at worst could actually damage your building irretrievably.

Matthew

If you want to see what I went through with this house, check out my blog at http://houseintheenchantedforest.blogspot.com/ and filter on "dampness".

 

[Roger H]

It has suffered with damp which we assume was due to poor pointing which has now been redone.

Hopefully in lime mortar?

 

[Tevez]

Thanks for your help. As you can probably tell as this is my first home, this is all new to me and I'm trying to learn and research things before I go ahead and have them done.
I'm not sure if lime mortar was used for the pointing as this was a while before I bought the property.
From what I'm understanding so far, the companies that are advising me (obviously want my money) but are treating it as a newer property and therefore wanting to carry out modern techniques.
I will check everything that has been mentioned as potential causes for the damp. So am I right in thinking that I should ignore advice that damp proofing is required?
If I can't find the problem myself, would a survey from an independent company be advised? (I.e from somebody who has no financial gain in whatever they advise me). Thanks for your help and excuse any of my questions that may seem obvious. I just want to get it right before I move in and have any ongoing problems.

 

[Spoilt Victorian Child]

Hey Tevez, check out this guy's site about damp and old buildings.

http://www.heritage-house.org/managing-damp-in-old-buildings.html

There's no one answer I can point you to, but he has a few pages of text and a lot of videos where he's exploring old buildings and their damp problems (usually caused by modern building techniques/materials). Spend a bit of time digging through, it's a great education into how various types of old buildings were built to deal with moisture and damp of their own accord, which helps widen your perspective. He loves investigating the myths and lies of modern damp companies, and gives the proper solutions which are suitable for old buildings.

I had a survey done by him on a recent purchase. He absolutely knows his stuff, and took time to explain why things were going wrong in the house and how to fix them. He spent a full day on site with thermal cameras, humidity probes, etc... It wasn't cheap, but realistically not much more than a full homebuyers survey, which generally aren't worth the paper they're printed on and done by 'surveyors' who wouldn't know where to stick a humidity probe if they even had one.

 

[Tevez]

Hey Tevez, check out this guy's site about damp and old buildings.

http://www.heritage-house.org/managing-damp-in-old-buildings.html

There's no one answer I can point you to, but he has a few pages of text and a lot of videos where he's exploring old buildings and their damp problems (usually caused by modern building techniques/materials). Spend a bit of time digging through, it's a great education into how various types of old buildings were built to deal with moisture and damp of their own accord, which helps widen your perspective. He loves investigating the myths and lies of modern damp companies, and gives the proper solutions which are suitable for old buildings.

I had a survey done by him on a recent purchase. He absolutely knows his stuff, and took time to explain why things were going wrong in the house and how to fix them. He spent a full day on site with thermal cameras, humidity probes, etc... It wasn't cheap, but realistically not much more than a full homebuyers survey, which generally aren't worth the paper they're printed on and done by 'surveyors' who wouldn't know where to stick a humidity probe if they even had one.

Thanks for that. I stumbled upon that website yesterday and found it useful but I didn't have the time to read it thoroughly but I'll make sure I do.
Would you mind sending me a private message with how much the survey was please? Just to get an idea really as I was going to contact them about the possibility of a survey but I'm up in West Yorkshire so would need to find someone similar, who are closer.

 

[Lime]

Hey Tevez, check out this guy's site about damp and old buildings.

http://www.heritage-house.org/managing-damp-in-old-buildings.html

There's no one answer I can point you to, but he has a few pages of text and a lot of videos where he's exploring old buildings and their damp problems (usually caused by modern building techniques/materials). Spend a bit of time digging through, it's a great education into how various types of old buildings were built to deal with moisture and damp of their own accord, which helps widen your perspective. He loves investigating the myths and lies of modern damp companies, and gives the proper solutions which are suitable for old buildings.

I had a survey done by him on a recent purchase. He absolutely knows his stuff, and took time to explain why things were going wrong in the house and how to fix them. He spent a full day on site with thermal cameras, humidity probes, etc... It wasn't cheap, but realistically not much more than a full homebuyers survey, which generally aren't worth the paper they're printed on and done by 'surveyors' who wouldn't know where to stick a humidity probe if they even had one.

That's a good website and talks a lot of sense.

 

[Lime]

It has suffered with damp which we assume was due to poor pointing which has now been redone.

Hopefully in lime mortar?

Yes, a very important and pertinent point.

 

[Spoilt Victorian Child]

Thanks for that. I stumbled upon that website yesterday and found it useful but I didn't have the time to read it thoroughly but I'll make sure I do.
Would you mind sending me a private message with how much the survey was please? Just to get an idea really as I was going to contact them about the possibility of a survey but I'm up in West Yorkshire so would need to find someone similar, who are closer.

Have PM'd you. I think he's got a few contacts around the country, so if he can't make it up to Yorkshire he might know a man who can. Worth asking.

 

[Tevez]

Thanks for that. I stumbled upon that website yesterday and found it useful but I didn't have the time to read it thoroughly but I'll make sure I do.
Would you mind sending me a private message with how much the survey was please? Just to get an idea really as I was going to contact them about the possibility of a survey but I'm up in West Yorkshire so would need to find someone similar, who are closer.

Have PM'd you. I think he's got a few contacts around the country, so if he can't make it up to Yorkshire he might know a man who can. Worth asking.

That's brilliant. Thank you for taking the time to respond in the detail that you have. It's really appreciated. If I don't get anywhere soon I'll be giving them a call.

 

[Zebra]

When you say the house "has suffered from damp," what symptoms are showing up? Is the house being lived in at the moment? It may well be that you do not need the solutions the damp companies are offering you. Furthermore, it would be a very good idea to live in the house for a while and get a feel for it before considering anything as drastic as the measures you describe. We sometimes see on here posts from people ripping off such inadvisable solutions and returning the house to a state where it can breathe as it was designed to do.

 

[Tevez]

When you say the house "has suffered from damp," what symptoms are showing up? Is the house being lived in at the moment? It may well be that you do not need the solutions the damp companies are offering you. Furthermore, it would be a very good idea to live in the house for a while and get a feel for it before considering anything as drastic as the measures you describe. We sometimes see on here posts from people ripping off such inadvisable solutions and returning the house to a state where it can breathe as it was designed to do.

The house hasn't been lived in full time for a couple of years as it was my gran's and she was in and out of hospital/care homes.
The pointing was damaged and was redone a couple of years ago but I'm not sure if lime mortar was used for this.
The house had peeling wallpaper and when I stripped it, some of the walls were wet to touch. Also some had plaster crumbling away with the paper. I was advised a while ago to remove all of the plaster to let it dry out which is the stage I'm at now.
I know what you mean about living in it first but I'm having everything done before I move in and don't fancy the risk of it being damp again and starting from scratch.

From my research and the help on this forum I don't believe the damp companies are advising me correctly. This may be due to the fact that they're treating it as a newer build and therefore advising me on modern solutions which aren't required.

 

[Spoilt Victorian Child]

If the wallapaper's been put on lime plaster, you might get away with just peeling it off and the plaster would dry of is own accord (assuming it hasn't been painted with a modern paint). Or have you took the plaster off now?

Has there been any other modern installations - eg double glazed windows (without trickle vents) that could have caused excess moisture/condensation to get trapped in the rooms?

 

[malcolm]

My house had been empty and boarded up for a year when I bought it. There was water streaming down the walls and damp readings were quite high. I moved in and turned the heating on and opened a few windows. It's fine now.

The thing I really like about my house is that is has been neglected for 100 years and there is very little cement or plasterboard. Everything is lime. Lime is brilliant and by far a better material to have on your walls to tackle damp than anything else.

It is a shame you have been pointed towards modern damp solutions. I would suggest reading through every single post on this forum as I did when I bought my house. It saved me making some big mistakes. Mainstream techniques and advise are at best ignorant and wrong and at worst fraudulent, but it doesn't take long to get more understanding than the average builder or surveyor - that will be 10 minutes time well invested. Heritage House website is worth a look too.

 

[MikeG]

......Has there been any other modern installations - eg double glazed windows (without trickle vents) that could have caused excess moisture/condensation to get trapped in the rooms?

It isn't the glazing that is the issue, it is the ventilation. Putting triple or quadruple glazing in the room would not increase the condensation levels (indeed, it would do the opposite). It is the ventilation (in this case trickle vents) that counts with regards to moisture being trapped.

 

[Tevez]

I have removed most of the ground floor plaster now, just got a little bit more to do.
I'm really glad I found this forum before I've wasted my hard earned money! I don't believe that the pointing has been done with lime mortar so would you recommend I have this redone? It's a shame as it's a really neat job and been done fairly recently! I will be having my plasterer use lime plaster and I'll use lime paint too. Hopefully when this is done and I'm living in the property, having the heating on etc I should start to see an improvement. Without having wasted money on modern techniques!

 

[Tevez]

I have removed most of the ground floor plaster now, just got a little bit more to do.
I'm really glad I found this forum before I've wasted my hard earned money! I don't believe that the pointing has been done with lime mortar so would you recommend I have this redone? It's a shame as it's a really neat job and been done fairly recently! I will be having my plasterer use lime plaster and I'll use lime paint too. Hopefully when this is done and I'm living in the property, having the heating on etc I should start to see an improvement. Without having wasted money on modern techniques!

 

[Zebra]

It's a shame that the pointing has been done in cement, but absolutely inevitable if it wasn't specifically requested in lime. Few contractors are up for working in lime, although hopefully this is changing slowly as more people cotton on the old methods.
It probably isn't worth raking it all out and doing it again. For one thing, it may do more damage to the masonry taking the hard cement pointing out.

 

[Spoilt Victorian Child]

......Has there been any other modern installations - eg double glazed windows (without trickle vents) that could have caused excess moisture/condensation to get trapped in the rooms?

It isn't the glazing that is the issue, it is the ventilation. Putting triple or quadruple glazing in the room would not increase the condensation levels (indeed, it would do the opposite). It is the ventilation (in this case trickle vents) that counts with regards to moisture being trapped.

New double (triple or quadruple) glazing would surely seal the room up and trap condensation, compared to original rickety old sash windows that you can feel the wind through? Please explain?

And are you saying trickle vents aren't enough ventilation to counter moisture in a regular room? (eg lounge, bedroom)