Underfloor Ventilation - Airbrick

[AMParsons]

Hi

I have been informed by a surveyor that the single Airbrick I have in the bay of my 1900s Terrace is not adequate ventilation for my suspended wooden floor. Would you be able to help with these questions:

- Does anyone know the calculation for ventilation per airbrick?
- Would an additional Airbrick beside the current one, meet my needs?
- Can you fit an airbrick from the outside only, without pulling up the floor?

By the way, it is not a cavity wall.

Hope someone can help.

Alastair

 

[kevplumb]

most have the free space stamped on them if not mesure the holes and add together

yes

i suppose you could but it should be sleeved through the wall

 

[DAZB]

If you are in a through terrace and not a back to back you would be better fitting another airbrick at the back so it will help to draw airflow straight through the building. If you only have the front external wall then fitting another will certainly help and it can be easily fitted from outside by just removing a brick and replacing it with a suitably sized airbrick and bed it in and point up as normal.

 

[SD Carps]

It might be worth raising the question to the surveyor about the properties of the air brick,ie,if at present you have clay bricks,ask about getting them changed to the plastic ones,I appreciate that they dont look no-where near as good but the ventilation from a plastic air brick is almost twice of that from a clay one.
DazB is spot on regarding the air brick at the raer(if you havent already got one)this will give you plenty of cross ventilation which underground floors really need!!!
Hope it all works out
SD carps