External wall vents closed off - WHY?

mchu6am4

Buying 3bed semi and noticed the cavity wall air vents are closed off (cemented) - anybody got any idea why this could be done?

Is it something to do with cavity wall insulation? (as there is insulation installed - wool)

Thanks, Ash

Doozergirl

Have you asked your vendor?

They were probably cold and thought they were being clever :rolleyes:

mchu6am4

the sellers are selling on behalf of their parents - and say they don't know. The parents are about 80 and probably cannot remember as the house is vacant.

Could it be anything to do with the insulation?

Ash

PROFESSIONAL_LANDLORD

mchu6am4 wrote: »

Buying 3bed semi and noticed the cavity wall air vents are closed off (cemented) - anybody got any idea why this could be done?

Is it something to do with cavity wall insulation? (as there is insulation installed - wool)

Thanks, Ash


Is this a timber kit house ?

Do you mean the small vents 10mm x 65mm that sit in the brickwork joints ?

Have you had the property surveyed ?

mchu6am4

No, its a traditional brick built 3 bed semi - these vents are about 6" above ground level and about two bricks high.

I had a full building survey done on it but the surveyor made no mention of these although he did pick up the fact that there is cavity wall insulation installed (rock wool).

Ash

silvercar

if there is no longer a cavity, there may no longer be a need to ventilate it!

mchu6am4

silvercar wrote: »

if there is no longer a cavity, there may no longer be a need to ventilate it!

Yes, the cavity has insulation installed in it - is that what you mean?

silvercar

mchu6am4 wrote: »

Yes, the cavity has insulation installed in it - is that what you mean?

exactly.

blocked or insufficient vents usually show in surveys, so if the surveyor didn't mention it I wouldn't worry.

harryhound

We built a house when I was 8 back in the 1950's.

It had cavity walls but it was cold and horrible in the winter. Every room without a chimney had to have an airbrick in an attempt to get rid of condensation on the walls. Mum promptly stuffed cotton wool in all of them except the one in the larder!

The air changes per hour must have been off the scale as our pathetic coke boiler tried to heat the street.

Now it is much more scientific, with a cavity full of foam and an inner leaf of light weight (aero chocolate foam) type blocks glued together with something like "no more nails" the idea is that the inside stays so warm that condensation and mould is all in the past. The natural porosity of the walls is probably enough for the air we need to breath.

New buildings have to be pressure tested (ie they put a blower in a door or window and see if they can raise the pressure inside higher than outside to check that there are no cracks !)

Hope you enjoy your nice modernised home.

Harry

cattie

Funny, I've only noticed this week that vents to the upstairs bedroom at the back of the house are now blocked up with some kind of sealant stuff.

I'm fairly sure they weren't blocked in this way before I had the cavity wall insulation done last November, so have been wondering if it's done to stop the cavity stuff escaping through the vents? Sorry if it sounds daft, but it's the only thing I've been able to think of.

Tiger_greeneyes

As you've had a building survey done, then you will be entitled to contact the surveyor - I'd do just that - he obviously knows the house and will be able to give you definitive advice.