Closing off vents

[doobstoo]

I was wondering if I could pester you good people for some advice. My house (1932 semi in Essex) has, in every room, vents built into the walls. These look a little like airbricks from the outside but are high up in the walls. On the inside they are a metal grid buried into the plaster. Obviously they provide ventilation but they also increase my heating costs and modern houses (and older ones) don't seem to need them.

Would there be any negative impact if I were to fill them with expanding foam, ie block them up? I guess the degree of ventilation would decrease but I find that desirable. There's enough of a draft through my ancient doors and windows anyway! Is there anything I'm missing? Will blocking them up increase dampness somehow (there's no damp problem at the moment)?

 

[freddiemercurystwin]

Removing or blocking the vents will undoubtedly decrease the available ventilation, if there is not enough background ventilation condensation can occur. Nobody on here can say for certain whether you will get condensation problems, you may or may not, generally if you have trickle vents in the windows proceed with caution, if you do not have trickle vents you'd probably best to leave them freeflowing. You could stick something over them and see how it goes over the coming winter before you permanantly seal 'em up though. Modern houses do have ventilation, usually as trickle vents in the windows.

 

[RedHerring2]

Or you could replace the inside metal grid with a hit & miss vent, something like this:
http://www.yourhomedirect.co.uk/acatalog/hit_miss.html

 

[garyo]

If not already fitted, you could also help minimise the condensation risk by fitting an automatic bathroom extractor fan that's wired to the light switch on a delay timer.

Gary

 

[doobstoo]

Thanks for the advice guys, I didn't realise modern windows had vents in. I'll temporarily block the vents and see how we go.

A bathroom fan is purchased but not yet fitted, I'll have to get on with it!

 

[Robert9999]

There is another factor to bear in mind. When we bought our bungalow 13 years ago we had a gas engineer inspect the sitting room fire which we suspected had been a DIY installation. The gas chap immediately condemned it partly because it was too powerful for the room without an airbrick. (There was a more serious fault which I have mentioned on another thread.)

If the rules haven't changed since then, you may need to check whether any gas fire you have in the room can work without the added ventilation.