Air Bricks / Ventilation / Draft Proofing Help and information on all topics relating to your central heating, air conditioning and ventilation issues.

[watty_123]

Folks,

Hope this is the correct place to put this topic.

We recently moved into a 1920's terraced house. It's a big old house with a lot of draughts... I've worked through solving most of them during the summer, we had cavity wall insulation done but the house is colder this winter than last. The ground floor is a raised wood floor with a cavity underneath. During the cavity wall insulation "fitting" the company noticed the rear air brick was blocked so they fitted a new airbrick. Since they fitted this brick - correctly - the draughts coming up through the floor quite noticable. The rooms themselves are quite warm with the central heating on, but the floor is cold. We fitted carpets and some decent underlay, not the top of the range but mid range underlay. Problem is we have a one year old who is crawling around the floor and I'm concerned she will get colds due to the temperature.

Is there anything that can be done other than temporarily block the airbrick again. I know this is a big no no but I'm getting a bit desparate as to what I can do. I really don't want to resort to that.

I've read a few sites but a lot of them say be careful what you do in case it causes dry rot which I really don't want.

Filling the gaps between floorboards seems simple enough - but I'm not sure if this will cause more problems. Can you put a barrier around the air brick to try and prevent cold air blowing through?

Really stuck and would appreciate some decent advice before I pay someone to come in and suggest something simple which I should have thought of.

All thoughts appreciated.

[stoneyboy]

watty_123,
If you have had carpets and underlay fitted throughout draughts should not be a problem.
If flooring level is still cold you may have a gap around the rooms where the skirting board meets the floor - if this is the case try sealing it up.
Closing up the floor vents is not a good idea.
end

[dobber1]

It is a miss conception that airbricks allow wind to blow into the floor void and cause drafts.

Airbricks work on the principle that air is sucked out or moves out of the void due to pressure differential.

The floor void will naturally be colder due to this area being unheated. I am assuming your property is heated by radiators which are convectors and result in heat rising and can make the lower level feel cold or that drafts are evident.

You should get professional advice from someone registered with the property care association PCA before thinking of installing any underfloor insulation as I have recently undertaken a pre mortgage survey where the floor void was insulated incorrectly and the insulation was saturated and this has resulted in dry rot affecting the ground floor structure.