Damp mouldy home with Blocked external vents and condensation

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Hello all,
Looking for some advice please.

I bought a room bed detached bungalow last year in April. The bungalow has a heatrea sadia electric boiler supplying heat via radiators to all rooms.
I have UVPC windows, old bit with trickle vents.
I also have a PIV in my loft which I was told was for the previous owner for asthma problems.
Anyway, winter was freezing! And I had condensation on windows and walls developed a smell of stale cigarettes/damp.
Now the weather is better I've moved furniture about and found powdery black mould, which I have wiped off in internal walls.

All internal vents have been removed previously and plastered over.

I have two to three air vents on every wall around the detached bungalow.

I have removed the vents and they have a plastic sleeve in, filled with expanding foam and old newspaper.
The newspaper smelt badly of damp.
They didn't vent anywhere as internally blocked.
I removed the sleeve and I do have cavity wall insulation. The small particle one which is blown in.

My question is... are these plastic vents OK to be blocked both sides? Is the plastic tube supposed to be there?
Could this be causing damp and smelly walls?
As I have the PIV is this OK?
Thanks in advance, smell is horrid!!
Kids toys that fall down by bed against wall smell really bad, and have to be washed!
 
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If the vents lead to nowhere i would take them out and brick up.....i presume you dont have a suspended wooden floor and vents for that?

PIV should be stopping the condensation. Make sure its working correctly.
 
Damp and smelly walls? Condensation and mould?

Yes of course you need more ventilation.

The numbskull who blocked it up is responsible for your problems

And the money wasted on PIV in an attempt to cure the self-inflicted injury is ridiculous.

Insulation will reduce heat loss, but insulating is not the same as blocking ventilation.
 
Thank you that's exactly what I thought! I'm going to unblock the vents, cut all the expanding foam put and reinstate the vents. It was an elderly person's bungalow and I expect she's been done! I had no damp issues on survey , but they did have heating and piv running every time I viewed! Thanks for reply
 
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Just additionally to be clear I leave the plastic tubing in and connect a vent both sides? Sorry I'm not used to doing DIY myself!!!
 
Rubbish.... The wall vents are not needed. They will cause more issues. Block them up properly from outside. Remove vents and brick up.

Wall vents are only needed for suspended floors.

PIV systems do work.

Condensation is caused by warm air settling on a cold surface. Those vents will make those areas of wall extremely cold.
 
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Ahhh really? So I don't have to do DIY horay!

I've switched up the piv to boost now too.
Thanks so much
 
Condensation is caused by water vapour in the house. You create it every time you breathe, boil a kettle or run a tap or shower.

Ventilation is how it gets out.

Cold air coming from outside holds less water vapour than warm air inside the house, so it lowers the amount of water.

I am a bit surprised there are still old fellers around who think that ventilation causes damp.

It doesn't.

It is a cure, not a cause.
 
I agree with John D.

This is something people often struggle to get their heads around as they associate outside with cold and wet, so seek to seal the house up to keep it warm and dry. It is wrong. You need ventilation and air flow. It is why new windows have to include trickle vents even though this technically undermines the thermal achievements of modern windows. It is just a fact of life that we have to open a window or otherwise let air in and air out, even if it means losing some heat.

Here is an example. I live in a dwelling like yours. I made the mistake of having it all plastered in December. This meant I had a lot of moisture to get shut of. My hygrometer showed the humidity was high, as expected with soaked walls. The one and only thing that helped to quickly dry the plaster out was air flow. I had the external doors wide open and windows open for hours every day when it wasn't raining. It was freezing! But the plaster dried. Air flow!

I have also found, in general, during the colder months that running a dehumidifier for an hour or so each day was worthwhile. Get yourself a hygrometer so you can understand the humidity in your home and how to manage it. Other things to do include keeping furniture away from external walls, keeping bathroom door closed at all times and especially after shower, use fan and keep window open when showering or cooking. I adopt a policy of containment wherever possible.

Vents should help, not hinder, in principle.

Hope this helps!
 
Trickle vents are very much different to big vents in the walls! They were fitted when fires were 'the' thing.....
 

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