Cavity wall air vent

[mark1a]

Hi guys I took the cover off the small air vent to see why not a lot of air was coming through. Found its a cavity wall and they used some sort of filler and that stopped a lot of air circulation. Now I will be putting back over the hole an adjustable vent. I assume I need to line the inner part. What can I use? Anything cheap was thinking some old tiles I have glued with hard as nails. But rather do a decent job

Also the middle pic shows ithe cavity doesn't go to the top. Good or bad?


Also do you guys recommend I get one of those tube heaters? This cupboard in our bedroom 3ft X 3ft X 8ft

 

[tomfe]

It'll probably be fine now. You could uus expanding foam to fill the gap. Damp it first with some spray water.

 

[Cavitech]

Hi Mark, just consider the fact that the vent could be there to vent the room and/or the cavity itself. Insulation can stop a property breathing properly.

 

[Leofric]

Hi Mark, just consider the fact that the vent could be there to vent the room and/or the cavity itself. Insulation can stop a property breathing properly.

Why would the cavity need to be ventilated ?
In what situation does insulation stop a property breathing properly ?