Damp Problem

GSte

Hi,

We've recently redecorated a room in which there was a damp problem on the inside of one of the external walls, and the damp has come back after 6 months (unsurprisingly I guess! ). The problem is that I am unsure whether it's condensation or penetrating damp. The symptoms are mainly that water gathers along the top of the skirting board and that everything on that side of the room grows mold, which spreads. We had a damp guy round to look at it and he said he thought it was condensation and that the solution would be to fit air bricks in the outside skin of the wall, and to keep the windows on the notches when possible to get some airflow throughout the house. We have cavity wall insulation however..... should air bricks be fitted to vent the cavity when it's full of insulation? Will they have any effect? Thanks for any help.

spadoosh

You can have a casing for an airbrick which would prevent the insulation blocking it. Though air will still travel through the insulation just at a slower rate (probably not good for the insulation though). Personally would go with opening a window more often, cheaper and less hassle.

Is it a ground floor room?!

tony6403

Air bricks in this situation would be useless.
Even if they did circulate air in your cavity ( which they won't because of your insulation ) this would make condensation more likely. This is because the inner leaf of your property would become colder which would increase the possibility of moisture condensing on it from the warm air within your room.
Start with the basics e.g.:
for damp
- do you have a damp course
- is the damp course bridged by debris
- is your pointing in good order
- any leaks from guttering or downpipes
- is there a window in the wall and if so is the frame sealed properly ; is rainwater dripping from the sill falling clear of the brickwork

for condensation
- do you dry washing indoors
- have you got a kitchen extractor to expel moisture from cooking etc.
- do you have a flueless gas fire

If the problem turns out to be condensation , and you can't reasonably reduce the source of the moisture ( not forgetting ventilation ) then you might consider getting a dehumidifier - this was the solution in my own case.