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615 Questions: Damp Proofing
Having stripped wallpaper in my dining room there is black mould in the corner. It is over two walls and comes up to about metre. The water pipe for the house comes along the wall and up the other wall (upto boiler upstairs) but there is no sign of water, wood damage to skirting etc. I have had two cupboards up against the wall...for about 5-6 years but when I did a quick decorating fix 6 months ago I didn't see lots of damp/mould.
One tradesman has said it is definitely not rising damp and it is just caused by condensation (being near the back door, covered by cupboards etc). He wants to sell me a basement damp machine but I don't want this and if it is condensation I'll use cleaner and solution in paint/paste.
The other tradesman said it was rising damp (though he didn't seem to want to offer any other solution and didn't really speak - he just poked the wall and made a hole in it with a screwdriver!) and he quoted me £1000 to do damp proofing.
I'd like to be able to know what the mould is caused by and how to identify it given that the experts in my area can't agree!
- Yrozway 2nd Jun, 2011 Damp Proofing
Upon further inspection and clearing the gully (FULL TO THE TOP WITH WET SOIL) is of brick construction, basically a wall against the house wall, a gap (of about 3 inches more in parts) and then another wall this retains the earth from the house, the depth - it appears to go down to the base of the house (upto 1 meter in parts). the bottom of the gully is brick too - so no soak away, the flags sit on top of the two walls covering the gully so i dont know about keeping 3 inches away because this would expose the gully. I cannot repoint in a gully i cannot get my hands down (my arms are not 1 meter long) and cannot get in with an exterior dpc. any ideas ? thanks
- Ymkr_71 6th May, 2011 Damp Proofing
We have just sold our house,and a survayer came in for valuation etc,and he mentioned there are few rising damp issues(only here and there,nothing major),as far i can see there is NO VISIBLE mark of any rising damp,apart from small paryion wall in kitchen,which is half tiled and half wallpapers(and there is some moister in the wall paper)
apart from that whole house is 100% nice and dry,so in that case,I am not going to take any chance,what could be the best soloution for it?can I drill through the tiles and fill some DRYZONE tubes,or do i need to take the tiles off or should I call in specalist,just wonder how big the job is?
- Ykumar_19 25th Nov, 2011 Damp Proofing
- Ychester_87 9th Jan, 2012 Damp Proofing
Hey there, i am looking for some advice!
My house has extensive rising damp in most of the lower house. I have had 2 different quotes;
Quote 1 advocates chemical injection to solve the problem. This has already failed on this house in the past. They said that plaster would need to come off the wall, then the walls would be replastered immediately.
Quote 2 advocates the use of plastic membranes. They suggest again taking the plaster of the walls and after a few weeks of letting the bricks dry out to replaster the walls.
I am really unsure what the best course of action is, and as I am meeting these builders myself and knnow little of the subject, I really dont want to be ripped off of for the wrong method to be used.
- Ynikkibush 30th May, 2011 Damp Proofing
What's the difference, how can I identify both, are there tell tale signs?
- Yalex_75 17th Feb, 2011 Damp Proofing
I think I have an interesting one for you all...
I have had a problem with damp patches appearing around my ground floor chimney breast and I would have though I first noticed an issue around 2 years ago. This is an INTERNAL wall and the construction is SINGLE SKIN brick. In June 2011, I commissioned an independent damp survey (CSRT qualified surveyors independent of any supplier) to try and identify the root cause of the problem.
The surveyor took damp measurements of the affected wall and created a damp profile. The moisture meter indicated elevated readings ranging from 70 - 90% in the plaster of the chimney breast and 40 - 60% in the plast of the adjacent wall. The skirting boards were 20%. Up to 1m the readings are fairly consistent and at approx 1m the damp readings stop entirely.
At my instruction floorboards were not lifted due to an existing laminate floor that I can't afford to replace at present. Samples of brickwork were not taken and the surveyor inspected the house from the outside but did not get up onto the roof or go into the loft.
The survey report identified the "cause" as being rising damp due to a missing or ineffective dpc in the chimney breast. Also possible bridging from the concrete hearth and associated earth mound allowing moisture to track up the brickwork and plaster. Unable to confirm whether the hearth is insitu due to the flooring.
Recommendation is to install a dryzone or vandex dpc in the bottom row of brick above floor level and replaster with sand+cement incorporating salt inhibitor. Plaster not to project more than 25mm below top of new skirting and min gap to floor of 25mm.
HOWEVER, from visual inspection over a period of time, the damp patches on the wallpaper gets worse very quickly during periods of heavy rain and gradually dries out over a period of several weeks when there is a dry spell (all too rare in north Manchester!).
The gas fire came out today and the hearth behind was full of rubble and soot. I have cleaned all of this out. I have had a couple of lads come out to quote for the
So then based on the above, is my problem:
a) Rising damp as diagnosed by the surveyor
b) Penetrating damp from a leaking chimney
c) Condensation being hygroscopic salts in plaster drawn through from brickwork behind.
d) Some combination of the above/ other
And based on that diagnosis. Do I:
a) Hire a dpc Contractor as per recommendation
b) Get a roofer to see what is what up top and fix any problems there as a first try.
c) Buy a dehumidifyer and run it hard for a few weeks.
Sorry for the essay, hope you found it an interesting one, any more info just ask, look forward to seeing responses.
- Ydavebee 27th Sep, 2011 Damp Proofing
Hi I've just had a new extension built and the render has been taken right to the ground, but water is seeping up walls past damp proofing course. Is this going to cause damp problems?
I am now being told they will paint the outside (for free) to seal the render. This sounds as though they are just trying to literally paint over a potential problem. Should I accept this or insist they knock the render off to the DPC level?
Thank you Joseph @ plasterworks for your response
- Yelliott_70 29th Jan, 2013 Damp Proofing
Condensation issue in front bedroom of small house, opposite bathroom
Walls are black/cold/damp around window, and where the wall meets the ceiling too. Walk in wardrobe smells terribly musky and the wall has got a lot of mould on too. Window always seems to have plenty of condensation on it.
Lead to believe this is a problem with condensation rather than damp.
What would be the best way to deal with this? Would it bit advisable to fit a couple of air bricks would this cause too much of a draught in winter? How about fitting a dehumidifier, would that help at all. And just how effective are loft ventilation units, they're probably a bit out of my price range to be honest.
Many thanks, any advice or help is most welcome
Forgot to add top of house is fully rendered bottom is brickwork which has recently been repointed (shortly before condensation problems seemed to appear).
- Ycmurphy 16th Feb, 2012 Damp Proofing
- Ycoatesey 11th Sep, 2011 Damp Proofing
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