Calling for builders advice - air bricks

cyclonebri1

You must be way down south, I understand cavity wall construction started on the south coast in at the very end of the 19th century, most homes were not built that way untill about the 1930's not that I' doubt you of course, but they were in there infancy at the age of yours.

Right, so it's a flat, that probably limits what you can do, but in agreement with above posters, someone has frigged about with yours to tackle a problem.

Unless I've missed it you haven't specified why you think it's damp, I'd put a pound to a penny that you have a condensation problem and that's only fixable 3 ways that I know of.

1 add extra insulation

2 change the air (ventilate) more often

3 heat to a warmer temp.

Most likely a combination of all 3 of these

I bet you will say your hose is cold too??

charlestonjive

Cavities are unusual in an 1890s house but not unheard of. I have cavity walls in mine. And they are definitely cavity walls because they've been opened up and I've had a good root around. We're very much inland as well.

I think as others have said, airbricks are for ventilating the wood floors, so the joists don't rot. I think mould is a different issue. Did you take out all the rubble in all the cavities? It seems to me that you have a combination of issues causing excessive soaking of the outer leaf of bricks (high external ground levels, land sloping towards house, guttering or downpipe issues for example) and rubble in the cavities causing that moisture to cross to the internal brick leaf.

If you cannot clean out all the cavities, start by reducing excessive soaking of the external brick skin. Do you have a damp proof course? What are the ground levels like in relation to it. Has a new driveway or patio gone above it? Are all your gutters and downpipes flowing well? Is water pooling near the house for any reason?

cyclonebri1

You have what I said earlier, condensation overload. It affects still corners, rising or penetrating damp will not cause the problem you have.

It's hard to say as money may be tight but open the windows a crack and put some heating on, it will get worse as winter approaches.:A

matty_hunt

Thanks for the replies. I will address all the airbricks and put sleeves in to direct air flow under the floor and retro fit some trickle vents to the windows. Internal condensation reduction measures have been put in place so hopefully things will be much improved.
Cheers all.

Gordon_Hose

Dehumidifier?

Can you fit an extractor fan with a humidistat? That will get rid of excessive moisture in the air which is condensing on the cold walls and eventually going mouldy.

robrentalrefurb

Hi Matty.
I too find it odd that a property of that age has been built with a cavity. But if they're there, they're there.

As long as there are no other rising or penetrating damp issues, having cavity wall insulation fitted will help.

condensation is a result of warmer air being able to hold more moisture, and having to dump it when it contacts a colder surface.

Ive recently written about just this issue- the main things to do to reduce condensation in your home ( some will always be present) is to reduce the amount of moisture made. Try covering pans etc when cooking, and close the kitchen doors or bathroom doors when in use to prevent the moisture from spreading around out of your 'wet areas.

Ensure adequate ventilation at all times, whether opening windows, trickle vents or mechanical extractors.

Keep your heating on low- this will warm the masonry and prevent such a temperature difference, and reduce the condensation. Having it on high briefly could make the problem worse.

Finally, if there is a cavity, the vent should be sleeved through it really.

Hope this helps!

cyclonebri1

matty_hunt wrote: »

Thanks for the replies. I will address all the airbricks and put sleeves in to direct air flow under the floor and retro fit some trickle vents to the windows. Internal condensation reduction measures have been put in place so hopefully things will be much improved.
Cheers all.

We try to help,

A final test that I always advise is quick and simple and will indicate if you have damp issues or simply condensation as I suspect.

Take a 1ft square piece of clear polythene.
Wipe an area of the wall where "damp" occurs.
Tape this poly to the wall with gaffer tape or similar, ensuring it is totally sealed
Come back tomorrow, if you have damp you will see water vapour/mist on the inside of the poly.

Other than that it really is condensation and the cure is as I said before.

Hope that helps;)