Blocking up an air brick

Justkassif · Post by **Justkassif** » Thu Jun 27, 2024 2:11 am

Sorry this might be abit to read but was wondering if someone can help me so I live in slightly older house which has no wall cavity and has brick air vent I’ve attached a picture below showing the air vent brick from outside which is located on my alleyway which is closed from above as it’s a mid terrace house and no rain gets near the air vent and the second picture is from inside my kitchen I removed the old plasterboards to find that this is what the air vent looks like from inside now I will have a plasterer come to replaster the walls I was wondering if anyone can tell me if it’s okay to leave a little gap between the air vent hole inside the house and plaster board and leave it as it is or shall I block this off as once plasterboard goes over it there won’t be any use internally from the vent but I’m worried blocking it off might cause issues to the bricks but on the other hand I’m worried leaving it as is might cause damp/mould or moisture in between the wall and behind the plaster board as cold air will meet warm plasterboard. should I put some expanding foam inside it and close it off completely or shall I leave it as is and just plaster over this also to note it was already like this and when removing the old plaster I didn’t notice any mould and I have french doors in my kitchen and a window no trickle vents on them though and I also have 2 vents in my upstairs bedroom and the chimney downstairs has been removed.
tyia

dewaltdisney · Post by **dewaltdisney** » Thu Jun 27, 2024 5:46 am

It could be an airflow vent from the early days of natural gas which came in during the 60s to replace town gas. Natural gas needs more air to burn and the addional airflow ensured there was not a build-up of monoxide. If there was a water heater or boiler in the room in those days they would not be room sealed flued and this would be the answer for the vent need. It serves no purpose now and I would brick it up. The only air bricks you should leave are ground level vents where air has to circulate in the subfloor area to prevent timber rot if there are wooden floors.

DWD

Justkassif · Post by **Justkassif** » Thu Jun 27, 2024 11:45 am

I was thinking that it may be a airflow vent that was mainly for allowing ventilation during the time they had natural gases too ah right perfect thank you and yeah I thought as much by leaving it open it will great cold spots behind the plaster board and no I know those vents serve a different purpose as it is for ensuring breathability of the joists and beneath the floor, thank you for clarifying it with me dewaltdisney