Need advice about this problem please

[Fordy81]

I've posted previously about this, but didn't really get any definitive answers.

Basically after ripping out the old kitchen I found this hole beneath. Having cleared out nearly a buckets worth of rubbish I'm left with the following.

There is about 100mm of concrete, then the dpm which you can see has been broken, then about 65mm of screed on top of that. Below the initial concrete is a void of at least 10cm and it goes both left and right. The soil pipe feels solid, although the top of the plastic pipe sits below the top level of the screed.

Presumably the gap under the concrete is normal, and somewhere there will be footings?

My problem is, how do I make this water/damp/draught/rodent proof? I need to get a plumber to either lift, or extend the mdpe pipe so the stop cock is accesible, but I'm wary of cementing it in. I was thinking of perhaps lagging it in something (not sure what) then cementing up to the dpm level. Then attaching new dpm. But then what? Should I cement further? Like I say, I can't bring it to floor level without cementing in the removable waste pipe attachment that goes to the sink.

Sorry for the long post but this is really troubling me.

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[Fordy81]

Anyone?

 

[jeds]

Pull the short piece of grey 100mm pipe out of the brown fitting and fit a longer length in. Make sure the rubber seal is correctly fitted, file off the rim of the new pipe and lubricate with washing up liquid. Gently push it in with a revolving action.

Don't understand the blue MDPE question. The stop tap is well above floor level and looks plenty long enough to me. If you must extend the pipe just cut it, add in a fitting with a new pipe on top. If you'd prefer not to concrete the fitting put it in a length of duct. You should be able to isolate the supply in the road.

After that fill the void with sharp sand. If the hole is dry and you are not well below general ground level and haven't generally had a damp problem there I wouldn't bother with a DPM. Just fill with concrete and top off with screed.

 

[Fordy81]

Pull the short piece of grey 100mm pipe out of the brown fitting and fit a longer length in. Make sure the rubber seal is correctly fitted, file off the rim of the new pipe and lubricate with washing up liquid. Gently push it in with a revolving action.

Don't understand the blue MDPE question. The stop tap is well above floor level and looks plenty long enough to me. If you must extend the pipe just cut it, add in a fitting with a new pipe on top. If you'd prefer not to concrete the fitting put it in a length of duct. You should be able to isolate the supply in the road.

After that fill the void with sharp sand. If the hole is dry and you are not well below general ground level and haven't generally had a damp problem there I wouldn't bother with a DPM. Just fill with concrete and top off with screed.

The grey pipe seems to be well stuck in. Is there any way of being able to extend it with a connector or something?

Bascially the stop cock will be pretty much under the units which would require me to remove the plinth etc. What sort of duct should I use? Plastic?

Thanks for the help

 

[jeds]

That grey pipe will come out. Grab it with a damp cloth or something and give it a twist - it'll move. Failing that buy a standard straight coupling and fit it on to the grey pipe and then fit an extension piece into that coupling - but it will come off if you give it enough. Always file off the rim of the pipe so it is at a sharp angle - ideally the sort of angle you'd get sharpening a pencil. Maybe a fraction less. And lubricate. Otherwise you'll chew up the rubber seal and the joint will leak.

You don't really need ducting if the blue pipe fitting is going to be above ground. Buy a straight fitting from B&Q or somewhere, cut the pipe square and clean just below the tap, fit the new fitting, add a length of pipe above and re-fit the stop tap. Fittings for blue MDPE are really easy to use.

 

[Fordy81]

That grey pipe will come out. Grab it with a damp cloth or something and give it a twist - it'll move. Failing that buy a standard straight coupling and fit it on to the grey pipe and then fit an extension piece into that coupling - but it will come off if you give it enough. Always file off the rim of the pipe so it is at a sharp angle - ideally the sort of angle you'd get sharpening a pencil. Maybe a fraction less. And lubricate. Otherwise you'll chew up the rubber seal and the joint will leak.

You don't really need ducting if the blue pipe fitting is going to be above ground. Buy a straight fitting from B&Q or somewhere, cut the pipe square and clean just below the tap, fit the new fitting, add a length of pipe above and re-fit the stop tap. Fittings for blue MDPE are really easy to use.

The pipe came out.

Put a new piece in that has a connection thingy for a reducer so that's sorted.

So just to confirm, it's perfectly fine to cement the mdpe in place? The stopcock is now inside the cabinet so is in the right place.

Thanks for the help

 

[jeds]

Well done. Better than sticking another fitting on. I'd slip a length of duct over the blue pipe myself. But only if I had a length handy - don't go out buying a 10m length! If you've got a local garden centre that does fish, you'll be able to buy a short piece there. It just needs to be a bit bigger than the pipe to allow it to move slightly. Just fit it slightly below and slightly above the concrete. If you can't get anything, just loosely wrap some stiff...ish poly around it.

 

[Fordy81]

Well done. Better than sticking another fitting on. I'd slip a length of duct over the blue pipe myself. But only if I had a length handy - don't go out buying a 10m length! If you've got a local garden centre that does fish, you'll be able to buy a short piece there. It just needs to be a bit bigger than the pipe to allow it to move slightly. Just fit it slightly below and slightly above the concrete. If you can't get anything, just loosely wrap some stiff...ish poly around it.

This might sound a daft question, but what exactly should the ducting be? Should it be plastic, or like pipe lagging?

 

[mfarrow]

It's just to provide a bit of flexibility/expandability to the pipe for that last section. Pipe lagging taped at the seam will be fine.