Just finished dismantling a corner bar (built by previous owners) in my
house and underneath I found a drain cover - great! - I think building regs
would not allow this in a million years now but the previous owner has built
right on top of the drains.

The existing cover is old, rusted and unfortunately whiffs as well - it's
not air tight.

Tried buying a replacement cover only and it did not fit - I guess the move
to metric etc etc.

ANyone have any suggestions on replacing a drain cover with something that
will remain accessible but is air tight etc etc?

Pointers in the right direction?

Cheers