Damp on internal wall between semi det

Discussion in 'Job Talk' started by Ross mcmahon, Jun 11, 2016.


Is this rising damp between our and our neighbours semi

  1. Yes

    1 vote(s)
  2. No

    1 vote(s)
  3. Maybe

    1 vote(s)
  4. Its going to cost whatever it is

    1 vote(s)
  1. Ross mcmahon

    Ross mcmahon New Member

    IMG_20160611_094938.jpg IMG_20160611_090707.jpg IMG_20160611_094928.jpg Morning all.

    New to the forum but here goes. Any advice or similar experiance would be helpfull.

    Please move to correct area if I've posted in the wrong section! View attachment 12576 View attachment 12577 View attachment 12576

    We have a victorian house (1905) built property, its a semi detached house and the photo shows an internal wall which joins to our neighbours semi. Its about halfway in the property which sits between our dining room and kitchen,

    This has been about for a couple of years and i keep thinking we need to sort it out. We had the dining room (to the right of the picture) plastered and decorated when we noticed the appearance of the damp patch evolve. The pipe you see stuck up we believe is a dead gas feed into the kitchen which we will sort when we intend to sort out. (Novices to renovation)

    The layout is a kitchen diner with the kitchen to the left as you look at the picture. And the fridge is the grey item on the left- (brand new btw)

    Any ideas if this could be rising damp or what!!

    If it is what would the cost be for rectification approx if anyone had a similar experiance!!!



    Attached Files:

  2. Scotmac

    Scotmac Member

    Hey Ross,

    This is a really common problem so don't worry about it too much. A lot of people when they get damp like this tend to put on damp sealers and re paint just for it to re appear again which isnt going to fix anything. You first need to find out the cause of the damp but I would strongly advise against getting in any damp proof 'experts' because they will charge a fortune and recommend solutions that can actually make problems like this worse down the line.

    Is it a sandstone property?

    Are there any other signs of damp in that room, maybe near window sills or doors?

    Is the room well heated and ventillated?
  3. Ross mcmahon

    Ross mcmahon New Member

    Thanks for reply ,

    It is not that we'll ventilated as we get a lot of mould up stairs but down stairs this appears to be the only problem, outside the house is small vents that are brick size that get blocked up with **** and need clearing, my fear is we will get rinsed by someone as we do not know enough about this subject.
  4. KIAB

    KIAB Well-Known Member

    Maybe a leak, has neighbour got a radiator on other side of wall?

    Easy enough to clear air vents with a wet n dry vac, it's very important to have free flowing air under a supended floor, as it stops damp from appearing & possible timber rot.
  5. Scotmac

    Scotmac Member

    Is the plaster rendered straight onto the wall or is it plasterboard on timber framing? You really need to see behind the plasterboard to try and get a better idea of what's going on. It could be a leak like KIAB says. How does the roof look between your house and the neighbour's?
  6. Ross mcmahon

    Ross mcmahon New Member

    All-its rendered straight onto the wall with no plasterboard-

    The vent bricks to the house are blocked nearest to it so will clean them-

    The neighbour has no problem,

    As for the roof-we have no idea. Would it be worth getting a roofer to investigate first maybe???
  7. Phil the Paver

    Phil the Paver Screwfix Select

    If that's an internal wall between you and next door it would be impossible for them not to have the same issue as you, unless the wall is a cavity, highly unlikely.

    Also remove those so called safety plug covers, they a so dangerous as they open up the built in safety cover on the socket.
    Pollowick and KIAB like this.
  8. KIAB

    KIAB Well-Known Member

    Not a roof problem, as you would signs of damp, water penatration on 1st floor first.

    Clear those vents, & it will most likely dry up.
  9. Pollowick

    Pollowick Well-Known Member

    Beat me to it ... I was going to post the same. A link to information on these items ... http://www.fatallyflawed.org.uk/
  10. Bazdaa

    Bazdaa New Member

    Did you get any joy with this Ross?

    I have a similar issue, and coincidently, there is a Fridge Freezer by the patch as well.

    Has the freezer defrosted resulting in a water leak?
  11. Bob Rathbone

    Bob Rathbone Well-Known Member

    Good point that, if the auto defrost water outlet on the freezer is not positioned correctly to go into the pot on top of the compressor, the water will leak out onto the floor, under the laminate and to the carpet. Then it gets sucked up the wall.
  12. Martint86

    Martint86 Member

    We had a similar problem, convinced it's next door but we tried and tried for a year with no joy with the neighbours, ended up knocking the plaster off, pinning dpmbrane to the wall and plastering over
  13. Mr Rusty

    Mr Rusty Well-Known Member

    Maybe peeps will think I keep playing the same record, but I expect its condensation. The bottom of a victorian wall sitting on the ground is going to be a heat sink, and fairly cold. Next to it we have a fridge which will be creating warm air, which can hold more water vapour, next to a nice warm kitchen. I expect what is happening is you are loading the air with water vapour in the kitchen and that bit of wall gets cold enough to fall below the dew point for that water vapour loaded air.

    You could do some tests - get a cheap digital hygrometer which tells you the temperature and humidity, then use a table to calculate the dewpoint. A cheap infrared surface thermometer will tell you the surface temperature of that bit of wall and you will see instantly if condensation is a risk or not. Those 2 bits of kit will cost peanuts when compared to any damp proofing remedies which may not work, and at least you will then know if its condensation or not.

    Here's a humidity table

    Take the actual temp and multiply the saturated vapour pressure by the RH from the hygrometer to give the actual vapour pressure. Compare that to the table and see what temp has that value as a saturated pressure, and that's the dew point. You'll find the dew point is much higher than you might expect!

    There is also another possible contributing factor and that is hygroscopic salts. If the walls contain lime in the mortar or plaster, and there have been coal fires in the past, it is quite possible that the normal reactions between the combustion products and lime have created the presence of salts (nitrates) in the plaster. These often appear on the surface of walls, particularly if it has original lime plaster. The salts are hygroscopic (attract water) so it may be that the appearance of damp caused initially by condensation is persisting because it is becoming locked in with salts which have leached from the wall.

    I am seeing this over dabs on walls in my edwardian house project - salts are showing up as patches on the skim in a few places - the wetness of the dabs caused the salts to be able to migrate from the wall.

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