Air bricks - trying to find where my cellar meets ground level

[chrissy_a]

I'm living in a house with a cellar which currently doesn't have any air bricks. I want to install some but I have no idea where the cellar wall meets the outside world. Using a masonry drill, I started drilling a hole about two bricks down from the ceiling of my cellar and have got about 30cm deep and still not reached outside. I tried a bit higher and the material is a lot harder to drill and the dust is coming out grey so I don't know if that's some kind of concrete?

Potentially stupid question but do all cellars have at least some portion meeting above ground level?

 

[cross thread]

Measure from window inside to floor.then outside will tell you.

 

[chrissy_a]

Would that calculation not assume that there is zero ceiling between floors?

 

[SFK]

Many many assumptions coming up..... (Including that your house is built on flat ground and not on a slope.)

The bottom of Joists are typically at the outside ground level.

You can see this at your front and back door are there is typically two bricks from outside ground level to the bottom of the door, which is where the joist is.

Air bricks are typically at this height so that they are above the ground, below the inside floor level, between the joists, and let air in between joists.
There is then a space below the joists of about a foot (so word is not on ground and air from air bricks can circulate.
Or in your case the cellar.

So it likely your ground level starts about the bottom of your joists. And that you need to be drilling out from between the joists.

Quick ways to check location of bottom of joists:
- check height of your front and year doors above ground level - is it much higher than a joist height?. Any area about two to three bricks below door is likely to be top of basement height.

- as above, Measure from window inside to floor. Then outside window down towards ground. This tells you the floor height. From there down there will be a joist (about two to three bricks). The remaining space below that is your cellar.


SFK

 

[chrissy_a]

Thanks for your reply.

Air bricks are typically at this height so that they are above the ground, below the inside floor level, between the joists, and let air in between joists.

I'm a little confused...are you saying that air bricks will need to be placed level with the gap between the floor of my ground floor and the ceiling of my cellar? How would the air get into the cellar?

 

[SFK]

are you saying that air bricks will need to be placed level with the gap between the floor of my ground floor and the ceiling of my cellar?

No, I am not saying where you should put your airbricks

I am saying that air bricks (in Victorian houses) are often located between or just slightly below the joists.
Simply because the bottom of joists are typically placed just above ground level.

I am saying that unfortunately there is a good chance that your whole wall up to ceiling level is below ground level.

Images of outside wall my help us.

 

[chrissy_a]

I am saying that unfortunately there is a good chance that your whole wall up to ceiling level is below ground level.

Ah ok, my neighbour has air bricks about a brick height above ground level which come out about a brick height below the ceiling in the cellar, but I don't believe this street is completely level.

No, I am not saying where you should put your airbricks

Wasn't implying you were

I am saying that air bricks (in Victorian houses) are often located between or just slightly below the joists.
Simply because the bottom of joists are typically placed just above ground level.

So I guess the question remains as to how the air coming in between the joists makes it into the cellar for ventilation?

Images of outside wall my help us.

Not currently at the house but will try to assist when I get back

 

[SFK]

So I guess the question remains as to how the air coming in between the joists makes it into the cellar for ventilation?

Lookup periscope vents. They drop air under joists.

Timloc Telescopic Underfloor Vent 5 to 7 Course - 5 to 7 course

Sold as a Box of 10

ironmongeryplus.co.uk

Telescopic Underfloor Vent Black 220mm x 215mm - Screwfix

Order online at Screwfix.com. Provides ventilation below suspended ground floors. Adjustable for 3, 4 or 5 brick courses. Free air flow of 6600m². Grille prevents entry of vermin. Tough, robust and resistant to decay. Use with Air Brick (Code 13873). FREE next day delivery available, free...

www.screwfix.com

 

[SFK]

Ah ok, my neighbour has air bricks about a brick height above ground level which come out about a brick height below the ceiling in the cellar, but I don't believe this street is completely level.

Issue with Victorian houses is that unfortunately over time people build up soil, and footpaths and patios around house.
So ground level can easily increase sometimes even covering airvents.

 

[Notch7]

Potentially stupid question but do all cellars have at least some portion meeting above ground level?

no, unfortunately you cant assume anything at all, it could be any height

if there is a window in the room above the cellar -you could take a measurement of difference between floor level and ground level outside, then you would need to know thickness of floor void