Just wondering can anyone advise. We had a survey done on purchase of our, very old, 19th century townhouse. There was some paint crumbling from the inside front wall but we were advised to dry line the whole front of the house. We did this, all apart from one small are in the hall and now, there seems to be more paint crumbling from there. A reputable damp proofing company have examined it adn said it is rising damp. They have quoted a repair price of €6000, including re-plastering but I have read on many forums that rising damp is frequently mis-diagnosed when in fact the problem is just moisture being trapped. Any ideas or experiences of this or similar problems and any suggestions on how to proceed?
Very often misdiagnosed. These old structures need to breath and will suffer the type of problems you are seeing if improper materials are used in renovation works which attempt to seal the wall surfaces.
The wall construction will typically allow an amount of moisture in during damp conditions. This is normal and will not cause a problem as the breathability of the wall should keep themoisture at an acceptable level. The walls are of a suitable width that the moisture reaching internal finish doesnt become a problem for finishes etc. After all it has performed ok for over 100 years.
Have you carried out works externally to this area which might be affecting it? or are the drylining works closeby perhaps and so causing a build up of moisture in the area which would have been free to breath until now?
Thanks for the reply Mickdw. We have not done anything but the previous owners laid a concrete floor where there had been a wooden one and I'm thinking this may have started the problem. The dry lining is on one side of a stud wall and that stud is also sucking moisture into it but I am not convinced it is rising damp. It's so hard to know what to do as the damp company obviously have a vested interest in diagnosing damp!
Any suggestions? would a reputable builder be a better bet or have you another option?
do the affected walls sound hollow when tapped? try it and do same on unaffected wall
are the damp company proposing injecting DPC course?
are they offering 25 year guarantee?
what remedial works have they proposed?
One of the walls is a divididn stud, between the hall and living room...that is just sucking the moisture from the outside wall, which is solid. will try the tapping. the damp company have proposed the following
Strip plasterwork up to 1.5m on walls as detailed above or higher where indicated on-site. – See quotation.
Drill and pressure inject a horizontal chemical damp proof course to BS 6576/85. A vertical DPC shall be installed at boundary wall junctions. - See quotation.
Scud and 1st render coat of cement and sand incorporation re-rendering additive to our specification. - See quotation.
Tank wall surfaces up to 1.5m above finished floor level in two coats Thoroseal Tanking agent. – See quotation.
Scud and apply 2nd render coat in sand and cement incorporating re-rendering additive to our specification. - See quotation.
To apply thermal board dry lining to the front wall and remove and repair plasterboard of the stud wall to the hallway internal wall. - See quotation.
Note:- Render to our specification. Do not use bonding plaster under any circumstances.
Works to external surfaces should include:- To be carried out by others
Reduce external level to at least 150mm below floor level where possible.
DRY ROT / WET ROT TREATMENT:
Preliminary Works:- To be carried out by others.
Initially we would recommend a course of opening up works be
undertaken. This should include the exposing of heads, lintols,
joist ends, wall plates and plugs etc. We will re inspect on completion
of these opening up works.
...what ya think?
It's so expensive!
And prohibited by Dublin City Council to be used on protected structures
You need an experienced architect or technician to see the building
Okay, thanks. If anyone can PM me any suggestions, I would be grateful.
Or any other suggestions?
Thanks for that Sinnerboy
I have been trawling the web as I supposedly have a "rising damp" problem in my house as well. I came across your post and quote from company which I assume is <SNIP> because the quotation/recommendation I got is pretty much word for word what you were given!!
Makes me very suspicious that this a template and stock answer/quote given!
It may be worth getting an independent surveyor with no damp proofing connections to give his/her opinion before spending the amount you were quoted.
I dont like the idea of some of the remedies they have suggested. Fair enough injecting a dpc with stop rising damp however you may not have rising damp and if that is the case, it is money wasted.
The quote also mentions tanking the walls to 1.5m. Given that these walls need to breath, I wouldnt agree with this. This would cover the existing problem but if the moisture is in the wall, it will most likely come out at a higher level so in effect this proceedure would be just moving the problem along.
IMO, you can either try to preserve the original structure and allow it to work as intended by allowing it to breath etc. This would mean allowing a certain amount of moisture into the wall structure but the thickness and construction material should allow the interior to remain damp free. Alternatively you can go about dry lining the complete internals but again great care would be needed as this can trap moisture too leading to further problems. Some of the rising damp companies are clown and will just sell their products to anyone.
I would suggest that you get an architect with specific experience in this area. I would further suggest that you would look towards all other possibilities of damp penetration before considering the rising damp cause.
What is the outer finish on the building, has it been changed perhaps from a stone finish to a more modern (wrong) plaster finish,
Are there open cracks in the structure or pointing missing from stonework?
Any other defects from what would have been original condition,
Path/ground levels too high outside?
damaged rain water goods leaking water?
Then internally, what work has been done, again, modern renders applied? This would effectively seal the wall to a greater extent that would originally have been the case.
Something which is often overlooked also is modern heating & sealing. These houses would originally have been operated with large open fires with temperature rising & falling from morning to night & from day to day with considerable drafts running through the house also. This would have helped balance out the moisture levels. Certainly you should be using adequate vents nowadays to counteract the effects of the modern windows/doors & central heating that you must have. Ive seen a case in uk where the installation of a mechanical ventilation & heat recovery system cured alot of these 'rising damp' problems.
Most important point here is Dont give these dampness companies any money until you are certain that the work is required because they will come in and fit a dpc and guarantee it for 25 years. However if your problems still persist, they will just say that they had successfully stopped any rising damp but that your problems now are further dampness areas which will need further examination
I'm now at that point. I've a new build but there are 2 sections of a basement that have dampness coming up from the floor.
I had the walls tanked. There was a 200mm overlap out from the base of the Shuttered wall. After removing sections of the plaster board it seems that the dampness is coming from the floor. I've the usual builder blaming talking guy and vice versa while muggins here is facing a 2k bill for injecting something in to area to seal the concrete.
I was told its about 200euro per metre to do but it will solve the problem. I've been told about using some other method that uses an electric current to repeal the dampness. But both companies have told me that they've not really done this on new builds.
Any one got advice on a new build with this issue?
Your build is very new - right ? Concrete needs 1mm per day to dry out .
You may have finished out too soon . In the long run that's good . In the short term you may have to put up with spoil decorations .
The electro system reverses the charges in the moisture repelling it back towards the ground. It is only for damp and would not be good enough where there would be force of water pressure driving water in. There is an electro system like this in use in Aras an uachtaran (Spelling?)
What system have you used to damp proof the new build basment. I know you said you have the walls tanked but did you tank the outside or inside? Have you got a continuous tanking layer over floor & up walls? Is it protected behind a concrete layer or ?
Injecting concrete to seal is a notoriously expensive procedure yet very common in commercial buildings where you would be dealing with large scale mass concrete walls with deep basments. Not too often seen in domestic buildings