Builders just discovered blocked-up manhole cover hidden under our patio...what to do?

[sugarhoops]

Extension started this week, ground works team arrived and started digging up our patio. Already on our patio we have a manhole cover that we've made sure is accessible at all times.

However now that builders have pulled up all the existing patio slabs, they've found another manhole cover right next to the house (in direct line with the accessible manhole cover) that has had concrete and patio laid over it (i.e. completely inaccessible) for the past 10 years at least.

What happens next? It seems daft to have 2 manhole covers for the same drains only 1 metre apart from each other...this newly discovered manhole would be in / under our new extension (the accessible one wouldn't). Can we apply to get rid of it, considering its been buried and unused under our patio for past 10yrs?

We Have one under our extension! The builder has been very ingenious and built a trap door which is nailed down (but can allow access) in the wooden floor and no one has ever even noticed!

The fact that you've not needed to access it in the last 10 years doesn't mean you'll never need it. There must be a reason why it's there. Can you get an expert to look at it.

Previous occupants of our house had cemented one over down the side of our house under a path. We had a survey done that included drains. They failed 'the smoke test' because of this. We ended up getting a reduction on the price because it was assumed the drains were faulty. It was only when the path was dug up to attend to the drains that the manhole was discovered. Nothing wrong with the drains at all.

It's annoying, but cheaper to sort out now than later on down the line.

Thanks for replying - I appreciate this is a very dull post!

So I came home and they've found yet another manhole buried under the patio...arghh!! Turns out not all of the manholes link to anything, they're just there but no pipes leading out.

LOoks abit of a mess, but the ground works team said not to worry and our (experienced) builder will sort it no problem....given that they didnt seem too surprised, i'm guessing it might be a common problem they come across.

Gah, we've not even dug the footings yet and they're finding the unexpected. I just see my furnishings budget disappearing on drains

It might be worth getting Thames water (or equivalent) to check it out for you. When we sold our house recently the buyers searches turned up a drain/sewer which they claimed was under the extension (which we didn't build so knew nothing about it - our searches previously didn't identify it). As we didn't have a 'build over agreement' from Thames water we had to pay for an indemnity to the tune of £600. Which definitely cut into my soft furnishings budget for the new house!