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How to cover wall air vents?

Growing in Experience

How to cover wall air vents?



Looking to do some minor energy efficiency works on our covering these wall vents up.


Suggestions on how we could do this? Small holes are on the inside and large holes are on the outer?


Should we also keep the single vents in the bathroom and toilet open and not filled?




Bunnings Team Member
Bunnings Team Member

Re: House air vents

Hi James (@James_M),


It's important to remember that static vents serve a purpose, especially in older homes. They provide ventilation to indoor spaces, help regulate indoor temperatures and prevent the build-up of excess moisture in wall cavities and rooms which can lead to mould outbreaks and damage to building materials. Newer homes typically do not have wall vents as they are of better construction, including materials with higher insulation properties, and don't suffer as much from moisture issues. Also, if the rooms have a wood fireplace or older unflued gas heater, the vents would have been installed to provide fresh air and inhibit carbon monoxide build-up. Please remember that there are building codes for the ventilation of a dwelling. I would advise you to check with your relevant building authority to ensure that blocking ventilation in these rooms complies with regulations.


If you haven't suffered from moisture issues, you can attempt to close these vents. Remember that if this is a bedroom, you'll need to crack a window at night instead; otherwise, you'll have condensation running down the window by morning. This condensation enters the window frame and begins the decay process. I'd suggest that screwing a thin timber board, cut to the same size as the vent, over the larger exterior holes would be the most straightforward solution. A neat solution for the internal vent would be to remove the cover, clean the inside with alcohol and then adhere some adhesive film over the holes. The cover can then be placed back into position. If you experience a moisture build-up issue, you can reverse the process to open the vent again.


Do you have an exhaust fan in the bathroom? If so, you can cover over those vents too. The toilet vents should be fine to cover over.


Please let me know if you have any questions.




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Just Starting Out

Re: How to cover wall air vents?

Great question. We wanted to fill in the vents in a 1920s solid brick home as we are getting the windows double glazed and the vents defeat the purpose of our attempts to have an energy efficient house. The hot/cold air rushes in and at certain times of the day even the sun stream in through the holes. No attractive solution has yet been found. 

Home Improvement Guru

Re: How to cover wall air vents?

Afternoon @DM1 

I had similar thoughts years ago in the last place I lived. In the end I decided that the house had them for a reason so left them as is. When I painted I made sure to reopen all the holes from the air vents in the loungeroom and dining room.

Reading through @MitchellMc's answer a light bulb went off for my bathroom issue...


I have flakey paint on the ceiling, I always thought it was because of no flashing on the roof tiles and water coming in and pooling on the plaster. The previous owners have pretty much painted over the air vents in the bathroom and as there is only an ehaust fan (no window) I think I know why the paint flakes....  


For your issue I have seen cowles that are on the outside of the house and curved down so breezes cannot directly push through into the interior places. Think the shape of a wave breaking and is fixed over the holes so they can still breath but not allow the wind in.



Bunnings Team Member
Bunnings Team Member

Re: How to cover wall air vents?

Hello @DM1 


Welcome to the Bunnings Workshop community. It's marvellous to have you join us.


Have you thought about using an Accord 10 x 30cm White Metal Wall Vent. This cover has a discrete lever that lets you control the opening. Another unit I suggest is using Haron International 150mm Round Jet Diffuser Ceiling Vent. It has an open and close feature and only needs a hole the size of 200mm perfect for inside use.


If you need further assistance, please let us know.




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Community Manager
Community Manager

Re: How to cover wall air vents?

Readers of this popular discussion might be interested in the opinions shared by community members in this Best Advice article - Can you block the air vents in an old brick house?


Hope it's helpful.




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