we own an upstairs four in a block flat that was built in the 1950's. the entrance door is on the ground floor with stairs leading up to the accommodation. there is central heating with double glazing and a uPVC front door. the area where you come in the front door has always been troublesome in terms of condensation / damp. is there a way of determining whether this is condensation or damp? what is the best way to ensure air circulation? air brick? ventilation grill in door? thanks for any advice.
condenstation / damp problem
- Thread starter low drains drifter
- Start date
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"The area where you come in" is a bit vague.
The ceiling, the floor, the walls, the door, the windows? Inside the flat or in the hallway?
Is the hallway heated, ventilated?
Where do you want to ventilate, the hallway or the flat?
The ceiling, the floor, the walls, the door, the windows? Inside the flat or in the hallway?
Is the hallway heated, ventilated?
Where do you want to ventilate, the hallway or the flat?
Apologies for my original message. There's always a tendency to assume the reader can visualise the property.
perhaps better to explain that these 4 in a block are like 2 semis split between the ground and first floor to provide 2 self contained flats. each flat has a ground floor door with the upstairs flat having stairs immediately as you come in through the front uPVC door. it is this area just behind the uPVC door on the wall that suffers from damp / condensation. the area is the width and depth of the uPVC door. the area we are talking about is not heated or ventilated. the area I would like to ventilate is the area where the damp problem is.
Is the damp/condensation high up or low down? Is it on an exterior wall, or a party wall shared with your neighbour?
Is there a letter box in the door? Any ventilation through the letterbox? How well does the door fit? Is the top of the stairs open to the rest of the flat?
The problems are that moist air is lighter than dry air, so moisture laden air will tend to drift up the stairs. But cold air is heavier than warm air so will tend to sink to this low point (probably condensing the moisture in the process). So one would hope to have cold dry air around this area. So it might be damp or it might be condensation, hence the questions.
By ventilating this area there's no guarantee whether the cold air will enter there, or the air will exit there, thus pulling the warm moist air from upstairs, which could exacerbate the problem. Normally air would enter at the low point and exit at the high points, but prevailing winds etc do not guarantee this.
Any air entering there from outside will have the same moisture content as the outside anyway, which could also exacerbate the problem.
Is there a letter box in the door? Any ventilation through the letterbox? How well does the door fit? Is the top of the stairs open to the rest of the flat?
The problems are that moist air is lighter than dry air, so moisture laden air will tend to drift up the stairs. But cold air is heavier than warm air so will tend to sink to this low point (probably condensing the moisture in the process). So one would hope to have cold dry air around this area. So it might be damp or it might be condensation, hence the questions.
By ventilating this area there's no guarantee whether the cold air will enter there, or the air will exit there, thus pulling the warm moist air from upstairs, which could exacerbate the problem. Normally air would enter at the low point and exit at the high points, but prevailing winds etc do not guarantee this.
Any air entering there from outside will have the same moisture content as the outside anyway, which could also exacerbate the problem.
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water vapour is lighter than air so would tend to rise up the stairway. The position you describe sounds more like rainwater penetration.
The age of the building, any weather protection of the door, and photos, would help.
The age of the building, any weather protection of the door, and photos, would help.
the damp is over the whole wall and is black in colour. It is on the inside of an exterior cavity wall. There is a letter box but little ventilation and the door is a snug fit. There is an internal door at the top of the stairs.
The property was built in the 1950's and would have had drafty doors and windows and no central heating. The main door to the flat is a 2 year old uPVC door with perfect sealing all the way round. There are droplets of water on the door all the way up.
meant to say that I will get photos and post these
Yes.
If there are stains, then its more likely penetrating damp. If its black mould, then more likley condensation damp.
But there could be structural defects which could be causing either
If it's condensation, I would suggest that insulation on that external wall will improve the situation very much so. The problem is it might just move it somewhere else.
Did you say the door had condensation on it as well?
Air bricks could easily be inserted in the external cavity wall. But this might create draughts up in the first floor.
If you search, especially this forum, there's plenty of threads about air bricks.
You could either core drill them, or stitch drill them. Bearing in mind that you'd need to place a sleeve in to bridge the cavity.
Did you say the door had condensation on it as well?
Air bricks could easily be inserted in the external cavity wall. But this might create draughts up in the first floor.
If you search, especially this forum, there's plenty of threads about air bricks.
You could either core drill them, or stitch drill them. Bearing in mind that you'd need to place a sleeve in to bridge the cavity.
next 3 are moisture round the inside of the front uPVC door
next 2 are thye outside wall
last one is the front door (open) and showing the upstairs internal door
There certainly does appear to be a lot of condensation.
First, I'd identify the pipework outside and reassure myself that there are no leaks. That means outside and where it passes through the cavity, although that would be difficult to identify and perhaps beyond a DIYer. It looks like there is a pipe pointing downwards. What is this?
There's also an overflow. Is this flowing/dripping water?
It looks also as though the dpm has been breached.
Does your neighbour suffer any damp/condensation on this wall upstairs?
Once you've assured yourself that the moisture/damps is not being caused by water from above or damp from below, I'd definitely install at least 2 vents through the external wall, one low, and one high. Perhaps low behind the front door, and one at high level by the upper door.
First, I'd identify the pipework outside and reassure myself that there are no leaks. That means outside and where it passes through the cavity, although that would be difficult to identify and perhaps beyond a DIYer. It looks like there is a pipe pointing downwards. What is this?
There's also an overflow. Is this flowing/dripping water?
It looks also as though the dpm has been breached.
Does your neighbour suffer any damp/condensation on this wall upstairs?
Once you've assured yourself that the moisture/damps is not being caused by water from above or damp from below, I'd definitely install at least 2 vents through the external wall, one low, and one high. Perhaps low behind the front door, and one at high level by the upper door.
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