Chanmenie

Thanks again @PeterWthat’s how I read it, so as I’m building with ICF (Isotex) I do have the option to use traditional method of running a copper pipe out through the wall and fitting a cage round it, or would it be preferable to use the HepVo waterless trap and discharge to an internal drain.

Thanks @PeterW the only minimum distance I can find is the 300mm minimum length of pipe below the tundish valve before any bends, or am I missing something

Hi @PeterW yes I read that on the G3 BR document, the D2 discharge pipe must be metal or polypropylene, but on the link I attached above it says the soil pipe can be PVC-U to BS1329 / BS 1453 which Osma soil pipe is.

I found this which shows discharge to soil stack so presumably discharge soil pipe is ok https://www.nhbc.co.uk/binaries/content/assets/nhbc/tech-zone/nhbc-standards/tech-guidance/8.1/discharge-pipes-from-unvented-hot-water-storage-systems-.pdf

Is it ok to plumb the discharge pipe from the UVC tundish valve into an internal drain if using a Hepvo or mcalpine self sealing waste valve. the UVC will be on the ground floor so I was planning on running a waste pipe under the slab to come up into the UVC cupboard. Does the pipe under the slab have to be 110mm ? or can I branch off the 110mm pipe that will provide drainage for the washing machine and water softener with something smaller ?

I’m having a go at doing it myself it’s hard work in this heat so only doing half days

Yeah I looked at them, they do seem to be very good but are very expensive have a chat with these guys https://cvcsystems.co.uk/products/air-source-heat-pumps/

How do you calculate the required size of a buffer tank ? I’m planning on using a 7kw Vailant heat pump with 150 or 180 litre Mixergy tank, Vailant recommend their 45litre buffer tank! Will that be big enough ? @Nickfromwales Thanks for the Cylinders2go recommendation

Yes exactly I have full planning approval which included foul waste connection to main sewer.

Very true, but I think the fact it’s surface water is irrelevant, it’s the fact I have a drainage condition means I can’t progress above slab level, because they won’t discharge any drainage conditions. Because they don’t look at them on an individual basis

I the only thing I have been told is that they won’t discharge my surface water drainage condition until they have suitable mitigation. So what’s frustrating is my surface water cannot get to a watercourse and to the broads. Basically they don’t have a clue what to do about any of it, so they are stalling

Well let’s hope so, I have full planning approval but can’t proceed above slab until my surface water drainage condition is discharged. And my surface water will go into a soakaway which is many miles from any watercourse or the broads

I’m doing the same, A193 mesh and 120mm concrete, so will cable tie the pipes to the mesh then lift in onto the 40/50mm rebar chairs.

So are you saying he has lied, if there’s any truth in what he has put I’m not surprised he has objected.to be honest.

As the other guys said they look like shrinkage / drying out cracks, pretty typical of mass new build estates.