Air brick draughts

Postby mrsnpearson » Mon Dec 01, 2008 9:32 pm


In our 1900 terrace property we have the original floor boards exposed. On instruction from our damp-course installers, we had to have 2 extra air bricks put in the front of the house in the bay, just below floor level. Now the cold weather is here, the floor area in the bay is of course very cold. We have applied sealant between the floorboards but this hasn't really made a difference. Other than laying a thick carpet, how warm up? Can we block up the vents for just the winter months and how?
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Simply Build It

Postby Perry525 » Mon Dec 08, 2008 8:02 pm

Afraid not.
The air vents are there to protect your joists and floor boards from rising damp.
If they are not ventilated they will start to rot.
The solution is to jamb sheets of polystyrene between the joists, tight under the floor boards, trying to avoid any gaps as your expensive heat will find its way through the holes and disappear.
Do the whole floor and the home will be much warmer.
I would guess that a house of that age will have other air vents for the various fires. These should be blocked up, as you are loosing a lot of heat through these. (Unless you have open fires)
To avoid condensation open the windows for a while each morning.
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Postby the specialist » Fri Jan 09, 2009 7:23 pm

The air vents are there to cross ventilate the sub floor void. Blocking them up will allow moisture evapourating from the ground to condense on the timber joists and floor boards - although in your case I would imagine as you have no carpets that some of the moisture is finding its way up into the house anyway.

Yours is a common problem which goes with the wanting a natural looking floor. If you can insulate below the floor fine but in my experience most older properties have very shallow floor voids.

So if you dont want a carpet and you cant insulate underneath there is a third option if you can afford it. Overlay the floor with engineered hardwood. It clicks together like laminate but is real wood so is warm to the touch. You still lay it on an underlay so you stop the drafts and retain the beauty of real wood.

the specialist
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Postby mrsnpearson » Mon Jan 12, 2009 12:12 pm

thanks for both your helpful advice!!
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