DPM insp' passed, but integrated garage manhole cover issue

[Pallatrax]

Hi folks,

Our extension is moving along, and the dpm was passed this morning, but my BCO told me I need to fit a sealed man hole cover in the integrated garage.

At present, I have a cast iron heavy-duty item in place ready for the concrete due tomorrow morning, and searching the interwebnet has only brought up normal duty sealed covers - so I'm at a loss.

I'm sure it is more important for the cover to withstand my defender driving over it than to let a small amount of gas into the garage.

Should I:
A) keep looking - they do exist
B) seal it with silicon
C) not worry as my door from the house will need to be sealed sufficiently anyway, and the manhole will only allow a negligible amount of gas out?

Thanks chaps - need to get this sorted asap as in work now, and concreting at 8am tomorrow!

Cheers
Tom

 

[Pallatrax]

Agh, found some, but too late I think!

On the hunt now for a seal to add to my existing 450mm round one!

Tom

 

[Pallatrax]

I've now stop flustering as we now have a rectangular heavy duty, double sealed bad-boy ready to swap when I'm home from work ready for tomorrow!

Cheers
Tom