Side extensions, manhole covers and kitchens

[Cretaceous]

We are planning a side extension in our 3-bed semi. However, if we extend the kitchen to the boundary, the manhole cover will be in the kitchen floor near the back door. Has anyone done this?

The person doing our plans says you can tile using a specially designed cover over the hole. You could then lift this up should you need to, and we could disguise it with a mat. This option would give us a good sized kitchen and a utility, and is a better design. But it seems a bit yuk, and would there be any smells wafting up?

The other option is a narrower extension, leaving the manhole cover outside. But this would give us an awkwardly shaped utility and a smaller kitchen. Layout-wise it's not so good.

What have other people done? Does anyone have a manhole cover in their kitchen? It sounds horrid, but is it in fact ok?

Not done myself but had a friend who had this issue if I recall - I think they moved the manhole cover so it fell outside the extension area. Not sure if this helps and is very vague.

and clearly they moved all the pipes as well - cos just moving the cover alone would be ridiculous - can you tell I had too much last night

We have this in our conservatory, which is open to the kitchen.
We could have had the manhole moved, which would have cost more, but the builders said the tile in cover would be fine.
It is ok - but if I was doing it again I would pay the extra and move it.
No problem at all with smells, it just doesn't look great (looks rubbish - we have a table over it so it doesn't really matter).
Also we have underfloor heating - but obviously not in that bit.

We have a manhole under our extension, we had a special covered used which is double sealed. We put carpet over ours so you cant' see it either.

We're currently having an extension built and are getting round the man hole problem by having a kitchen island over it. Unfortunately we'll lose some cupboard space as some sort of pipe thing has to come up into it, but this seemed better to us than having something visible.

That's really helpful. I don't thnk it would be easy to move it out of the kitchen area, as the extension would go right to the side.

Good to know there are no smells. We couldn't use carpet in the kitchen. But I guess we could put some sort of (modern!) lino over it rather than tiles. Or perhaps it would be too bumpy.

How would the kitchen island work, if you need to access the manhole? Would it be difficult to remove the island?

Which way does the drain run?
If it runs out towards the boundary then clearly you are stuck with it internally when you extend.

In this case you can get a "double sealed" manhole cover which has a recess in it for the floor finish to sit inside. You could ask to see one at travis perkins or similar. All you see at the end is a metal frame so it is not mega intrusive. The seals will prevent smells.

However if it runs parallel to your existing house then do shift it down the line of the drain to be outside. This is best in case of problems and blockages. Thankfully these are rare but when they happen the drain will have to be rodded. This means large plastic hose/rod things being shoved down the pipe to push the blockage away. It can get clogged with fat/grease/sanitary waste/make up or baby wipes (all should be binned but lots of people don't know they shouldn't be flushed). Obviously when there is a blockage shit backs up in the manhole and can splash around or overflow during rodding. Not good indoors! And blockages never come at a convenient time. Don't make that worse by covering a manhole over so you have to dismantle your kitchen to get at it.....

If it is a shared drain where you don't have complete control over what goes down it do everything you can to get the manhole moved outside. You also need permissions to build over shared drains so make sure you have that in place before you get too far.

Well I'm not entirely sure exactly how it works. because I have concentrated on my pretty kitchen and left all the boring, practical stuff up to DH At the moment there is a drain sticking up out of what will be the floor. The island is going to be built over it. The bit that sticks up will be in one of the cupboards so that it is accessible but still sealed. The only things that drain out via this drain will be the things situated in the island unit, ie the sink, dishwasher and washing machine. They've re-routed the toilet wastes so they aren't covered by the extension. (They used to go out via this drain.)
Reading this back, I'm not sure whether this helps or is as clear as mud!

I have a manhole cover just outside my front door. It has blocked and leaked across the drive 3 times now...

Not sure I'd fancy that indoors

Thank you for all your replies. It is a shared drain, so that's something to think about. We can't control what other people put down the drain.

If there is a blockage, our neighbour doesn't have an extension, so until he moves, we could unblock the drain there. But leaking sewage doesn't sound good. In our old house, we have had blocked drains, and it was unpleasant, but it didn't leak out.

I'm still not sure - I guess if the drain blocked every five years, I wouldn't mind the inconvenience, as the larger kitchen and utility would be worth it. But if it blocked every year...

We left the manhole outside and compromised the shape of the kitchen. We couldn't build to the boundary anyway, due to neighbours getting in first with an extension.

If it is a shared drain, you are no longer allowed to have internal manhole covers (following the transfer of ownership of private sewers), so you'd have to move it.

We had to apply to build over a shared drain (it was the mains sewer) to the water board. We then had to build special raft foundations, designed by structural engineer involving steel work - whole thing cost an extra £6k. No manhole though.

Hello

would be interesting to know how you got on with this? we have fallen in love with a place we are looking to buy and it has been renovated by a professional builder but the has a man whole cover in the kitchen... im not sure whether to let this dishearten me? last thing I want is sewage rising up in the kitchen!

I had a similar problem. I had a side and back extension.
I had the drains moved and had a manhole put in the garden. It's under the patio. I had a special cover put in that the patio bricks slot into. So you can't tell it's there.
Moving the drains wasn't expensive.

A friend has the lift up thingy with her wooden floorboards sunk into it and flush to the rest of the floor and it is not that obtrusive. There is a line of black plastic and a lift up hook thingy but really is not that bad. I have the same in my side return and our stone slabs sit within it so tiles would work too.

Having been through the dynarod experience for a blocked drain where the cover was in the garden - there is absolutely no way I'd consider having the manhole cover in my house!

I'd definitely move it.

Next door built over theirs with an extension and now don't have a manhole. So if they have a blockage they come here and use our hosepipe to jet the sewer, bastards

But you should never jet or plunge rod up the run of a sewer, only down the line. It can cause problems. But so far they've been ok.

We have just removed a manhole cover from under our kitchen cupboards to outside. It cost about £1500 but we need a new kitchen now as three cupboards and the worktops had to be removed.

We were getting a strong sewage smell and then rats started appearing in the kitchen - HUGE ones. The manhole over broke and the rats where getting through from there under our kitchen - and they had eaten through concrete - I kid you not. If possible - move it outside.

fifi

That’s sounds horrific. I hope your new kitchen makes up for that experience.

You really need to speak to an architect. If it's a public sewer, it means the water company has the right to access your property and do whatever they need to do to carry out repairs. This may involve damaging your kitchen, which the water company won't compensate you for. It's rare, but it's one of those low-probability but catastrophic-outcome type of risks.

You now need a build-over agreement with the water company if you are planning to cover these kinds of manholes. Note, though, that such an agreement doesn't mean the water company will never damage the kitchen if they need access!

You really need to consult (and pay for) an architect to tell you if you can build another access in the garden, outside the kitchen, or what kind of solutions would minimise the damage and the costs if access to the manhole is ever needed.