My daughter's flat has a damp problem at the back in one bedroom.
I'm sure that the problem stems from the ground level being higher than the
floor level at the back of the house. Here is the area outside the bedroom
The "ground" is about 5" higher than the floor and the area in the photo is
concreted and haunched (right word?) up the wall slightly to stop water
collecting next to the wall.
Immediately below the window though is an air vent through the wall and
this is level with the ground and has no raised lip.
What would be the best methods of reducing damp ingress? I did wonder
about digging it all out to lower the ground level but the drains are the
back of the house seem quite near the surface and without re-doing all the
drainage system, I'm not sure that's a starter.
I guess ground level higher than floor level can't be that unusual so there
must be other options. I imagine building a small raised lip along the
lower edge of the air vent would be a good idea.
Any other suggestions?
Cut a couple of channels on each side of the path. Get rid of the soil
and moss which are retaining moisture in the concrete. Raise the bottom
of the airvent by a couple of inches or block it up and make a new one
higher up the wall, if it's necessary.
It's less of a path, more of a "sump". It's bounded by walls at both ends.
On one side is the house, on the other a garden retaining wall. At present
there is a drain on the concrete surface that can drain surface water. I
would worry that digging trenches beneath the surface would just create a
non-draining "reservoir" right next to the house walls.
Raise the bottom
I think that's got to be my main priority. I've lifted some floorboards
and the solum feels dry apart from beneath the air vent.
I think shallow drain pipes have to be protected by a layer of concrete.
Is the soil free draining? If so I would create a gap between the
concrete and the flat wall and fill with pea gravel. This will reduce
rain splash onto the wall and allow air movement to reduce moisture
Internal condensation on a cold wall can be a problem but not normally
near the floor.
I have a similar problem with a drive level with the DPC level. The wall ha
s a vertical DPC and the gap between the drive and wall filled with gravel,
this arrangement has coped with everything the weather has thrown at it, t
he only problem has been around the air bricks but using some flue starters
to leave the air bricks open. No damp problems either in the wall or under
On Sunday, 15 November 2015 17:20:38 UTC, Tim wrote:
So you have a sump served by a drain?
It would be interesting to know where this drain goes to, it might only be connected to a soakaway. This could be silted up & the cause of the problem.
So first is to check it's functioning correctly & where it goes to.
Chemical injection might cure the damp problem.
Or coating the haunching with bitumous paint and sealing any cracks between the haunching and the wall with some sort of gunk.
It might be condensation, is there ventilation hood in kitchen? Are there similar problems elsewhere in the house?
Is there a damp course? If there is it's not obvious. The
efflorescence all along the base of that wall suggests it's damp all
along and been like that for a long time.
There are three down-pipes in the picture, all disappearing into the
ground. What are they? Do they all connect to the same drainage
system? Are those drains sound, or cracked and leaking into the
There's a lot of moss, suggesting it's a very damp area. Does the
grating below the nearest down-pipe actually drain water away, or is
the trap blocked, preventing surface water from draining.
Why does the render on the far wall above the inspection cover project
forward at the bottom? Is it to deflect water away from the base of
the wall? Is the gap below it choked up with moss and grot?
My immediate thought was to dig a trench all along the house wall and
put some heavy-duty polythene along against the wall, projecting up
above the level of the adjacent concrete, and then re-fill and make
I don't suppose your arse is any prettier. ;-) This is the "arse side" of
the flat. The rest of it is really nice.
I love her so much I wouldn't teach her to be dependant on others, she
bought it herself (without a mortgage). Drug dealing is clearly very
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