Damp walls in basement flat

[little1alien]

Hey

I live in a basement flat and as a result get problems with condensation.

we have a dehumidifier running almost 24/7. also have a fan running in the back room which has no windows,

but i am still getting what appears to be some sort of crystallisation

not a very good picture. any thoughts on how to get rid of it or stop it getting worse,
have had a look at condensation barrier paint.. but dunno if its any good

its not the best picture but can just about see it.

Untitled

• little1alien
• 3 Sep 2008
• 1

 

[JohnD]

crystals are probably efflorescence, caused when water is evaporating off the surface of the wall (as you are in a basement it is probably groundwater making the wall damp)

For condensation, increase ventilation. See //www.diynot.com/wiki/building:condensation_in_houses

penetrating damp is more difficult but look for wet ground round the building, caused by dripping gutters, leaking drains, paving sloping towards the house, and any signs of asphalt tanking or bitumen on the outside that has been damaged.

 

[little1alien]

nice one,

it is an old 1890's house,

plasterboard lined, with cavity behind onto unlined brick.

one side of the back room has what could be described as a ventilation duct but its pretty useless, no airflow
its the side of the pathway and thinking about it is more damp so could be a source of ground water.
the house is on a hill so the front entrance through the garden is fully above ground so that room is fine.

bought a tower fan a few days ago to help with the airflow so will see how that goes.

thanks anyway.

 

[hi1]

Tank the walls with either cement render and water proofer or a bitumin coating. The floor would need digging out, a concrete floor installing with suitable insulation under and a damp proof membrane tying in with what ever you do with the walls. If it gets really bad you may still need a sump with a pump to get rid of excess water.

 

[little1alien]

brutal - well thank god its rented

Think were safe from that drastic action at the moment but spose well have to see.

 

[JohnD]

more extractor fans, and better ventilation will make a difference to general dampess in your home.

the tower fan will just stir it about.

a crossflow from one end to the other is the best bet. You may be able to arrange this by opening windows at opposite sides so the wind blows through

If you are buying a extractor, a Centrifugal fan is quiter and more powerful than an Axial fan, and a 150mm more than a 1000mm. they use very little electricity so are cheap to run.