How many air bricks?

Rubyfw5 · 2023-08-18T14:10:44+00:00

Hi, I live in a small property consisting of a hallway, kitchen, bedroom, bathroom and living room. Windows in the kitchen, bedroom and living room. There's an extractor fan in the bathroom. Anyone know how many air bricks I should have please?

Rollercoaster1920 · 18/08/2023 15:45

None in a modern home. Just window trickle vents.
Older houses with open fires had one per room.

Original poster

Rubyfw5 · 18/08/2023 16:07

Thank you @Rollercoaster1920 , it's relatively new but with no trickle vents on the windows, does that mean I need air bricks? There's just one in the kitchen at the moment.

OP posts:

Original poster

Rubyfw5 · 18/08/2023 20:15

@pigletjohn if you're available, could you please give me your opinion? 🙏 I have a partly mouldy house and would be very grateful for any advice.

OP posts:

C4tastrophe · 18/08/2023 22:19

Don’t the windows lock partially open?
I’d upgrade the bathroom extractor fan first and set it to stay on for longer or have it on a manual switch.

primoseyellow · 18/08/2023 22:20

I thought air bricks ventilated a suspended timber floor? which trickle vents can't do?

Mygosh · 18/08/2023 22:28

You need advice from a builder. It really depends on the construction of your house. Trickle vents can usually be fitted to existing windows. Have you checked gutters etc outside? Any overflowing gutter can cause serious damp issues. If you have a water meter, check this isn't turning when you aren't using water. Even a small leak on your water supply could also cause damp. Poorly installed insulation (wall & loft) can also cause issues.

Which rooms are affected the most? Modern houses do not have air bricks because of efficiency. You should have a working extraction fan in your kitchen and bathroom.

C4tastrophe · 19/08/2023 06:51

primoseyellow · 18/08/2023 22:20

I thought air bricks ventilated a suspended timber floor? which trickle vents can't do?

They have two uses. Under the floor to allow ventilation, and often in older houses that would have relied on fires to keep warm, they’ll usually be in the bedroom walls, or any room with a fire, to allow ventilation.
They can also allow ventilation in unfilled cavity walls.

primoseyellow · 19/08/2023 07:24

@C4tastrophe Thank you , that's good to know as im looking to buy a house now!

C4tastrophe · 19/08/2023 07:40

@primoseyellow Every house needs ventilation as we breath out a lot of moisture, and then there is the cooking, bathroom, and just general differences in temperature that produce condensation ( cold bathroom and hot shower ).
In old houses with drafts, leaky windows and doors, they are practically ventilated enough, but when double glazing is installed, and efficient doors etc, the houses lose the ability to breath.
Air bricks are old technology though, as they allow heat loss, noticeable drafts, and noise. They are often covered or sealed.
The modern solution is a system fitted in the loft that kind of blows fresh air from outside into the house and pressurizes the house, and it vents out (somehow).
If I was buying a house, and it didn’t have any obvious damp, I would assume the house has enough ventilation. However there is a lot more to this topic no doubt.

BlueMongoose · 19/08/2023 21:13

C4tastrophe · 19/08/2023 07:40

@primoseyellow Every house needs ventilation as we breath out a lot of moisture, and then there is the cooking, bathroom, and just general differences in temperature that produce condensation ( cold bathroom and hot shower ).
In old houses with drafts, leaky windows and doors, they are practically ventilated enough, but when double glazing is installed, and efficient doors etc, the houses lose the ability to breath.
Air bricks are old technology though, as they allow heat loss, noticeable drafts, and noise. They are often covered or sealed.
The modern solution is a system fitted in the loft that kind of blows fresh air from outside into the house and pressurizes the house, and it vents out (somehow).
If I was buying a house, and it didn’t have any obvious damp, I would assume the house has enough ventilation. However there is a lot more to this topic no doubt.

I woudn't block any air brick unless I knew exactly what it was supposed to be doing, and that it was redundant in that regard.

PigletJohn · 21/08/2023 08:04

Is your question prompted by signs of damp or condensation?

When does the bathroom extractor run?

How do you ventilate the kitchen and bedrooms?

Is wet washing ever draped inside the house?

Some people have an aversion to ventilation and like to seal it up.

Original poster

Rubyfw5 · 31/08/2023 20:28

@pigletjohn thank you so much for replying and sorry I missed it 😞. I live in an annexe, part of the main house and then a converted double garage. The kitchen has an air brick and that and a third of the hallway that runs off it has no mould. The other two thirds of the hallway, bedroom, living room and bathroom have mould on the ceiling and walls. Extractor fan in the bathroom, stays on for 20 minutes after the light's turned off. We have windows open as much as possible and two dehumidifiers.

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C4tastrophe · 31/08/2023 22:11

Doesn’t sound like airbricks are going to solve that.
How was the garage converted to living accommodation? And is it the conversion with the damp problems?

PigletJohn · 01/09/2023 10:12

Experimentally, turn on the bathroom extractor, and leave it running continually for a few days. Modern extractors are very economical and only use about 10W of electricity, meaning they will run for 100 hours on one unit. Post a photo of it, and its outdoor vent, as some are too weak.

There may also be a plumbing leak, or roof or gutter. Close the internal doors and see if one room is particularly bad.

Tell me about the wet washing.

I don't know how often you open the windows.

Garages usually have concrete floors, and often no DPM, so damp can pass through them. Do you get damp under some impermeable object, such as a rubber mat?