External MDPE plumbing

[JDLDIY]

Hi there. I'm going to replace the lead water supply pipe to my property with new 32mm MDPE pipe. I'm pretty happy with how to go about it, but any tips would be gratefully received. I know it has to be 750mm below surface level, from what I can see I don't need to bed it in sand/gravel or anything? What sort of fitments would I need to pick up for the inside, to connect the MDPE pipe to my existing copper pipework? I'm wondering if I can T it into my existing pipework somehow before it's connected by the water company.

Also, I would like to T off the new pipe underground before the house and run a pipe down to the bottom of my garden to supply fresh water to an outbuilding. Is this acceptable? Do I need to put in an inspection chamber where I T off and what pipe fittings should I use to T off?

Any advice much appreciated.

 

[Newboy]

Just a couple of points:

new 32mm MDPE pipe

Have you checked that your supplier will accept 32 mm? - some will not connect sizes above 25 mm unless there are exceptional circumstances.

I don't need to bed it in sand/gravel or anything

Bed in sand, cover with sand and put a marker tape 200 mm below surface. The bedding and backfill avoids and bits of rubble damaging the pipe.

What sort of fitments would I need to pick up for the inside

Bring the new pipe through it's duct and straight to a brass stopcock (to BS1010) - sized to match your supply pipework and the internal pipework you're connecting too. (e.g. 25 mm/22 mm or 25 mm/15 mm). Immediately above the stopcock fit a draincock.

I would like to T off the new pipe underground before the house and run a pipe down to the bottom of my garden to supply fresh water to an outbuilding

No problem providing that the supply to your outbuilding is trenched as the rest of your supply. At the outbuilding you'll need another stopcock and (probably) a double-check valve.

Do I need to put in an inspection chamber where I T off

No need for a chamber - make a note of it for the future so that at least you'll know where the pipe and connections are.

what pipe fittings should I use to T off

MPDE 'T' to match your pipe size.

Unless you have very long runs then use single lengths of MDPE - no couplings underground

 

[JDLDIY]

newboy, many thanks for taking the time to reply - that was very comprehensive, V. Helpful.
I was hoping not to have to bed it in sand as I have long runs and that will add considerably to the cost.
The underground T fitting - is it best to use a compression type fitting, or is there another way to do it? It's obviously important to make as permanent a join as possible.
Yes, the water company are ok with 32mm pipe - I must supply a reducer or have one to hand

 

[Newboy]

Talbot fittings

 

[muggles]

http://www.cityirrigation.co.uk/aca...AtANWOGZsBoqsh8ztW0_MS5bt9PwSCc1h0aAoIl8P8HAQ