Air bricks

[Itsallpointless]

I have an extension on my home which was there when I moved in. I’m going to have some decking built and want to go over the air bricks. I have poked through the holes and the stick only goes a few inches and hits something solid. I think the air bricks may not be in use, is this normal for an extension?

Not a good idea at all to cover airbricks, they serve a purpose and sounds like yours need looking at..

Air bricks are not usually put there for decoration, it's probably ventilating your existing suspended floor. Get it checked out by a builder or ideally surveyor.