What is this?

[Tom JE]

Hi all,

I want to extend my patio but have this concrete cover over a deep hole right in the way. See pictures.

It looks like some kind of inspection chamber but it appears to be completely sealed. Does anybody know what it is or whether I can cover it up with a patio slab?

Cheers

 

[Ian H]

It’s a second lid inside the main lid. If you pull it off with grips there will be a Y junction for your drain under it.

I’d get a new lid that you can put paving in.

 

[frutbunn]

As above reply. It looks like a sealed inspection chamber. Pretty rare I've only seen a couple and I inspect drainage.