New Supply pipe and outside plumbing questions

[JDLDIY]

Hi there. We currently have a lead supply pipe and I’ve decided to replace it prior to embarking on a large building project. Whilst I’m doing it, I’m planning to T-off the new supply pipe to a standpipe (to wash cars/bikes/boots/dogs etc) and I’d also like to consider plumbing hot water pipes to the standpipe from the house in the trenches, if possible, whilst they are open.

I’ve had a roll of 32mm MDPE sitting around for years as I’ve been planning this job for ages.

My questions are;

1. Connectors - what would you recommend? I’ve been looking at JG Speedfit but they are really expensive. I’ve found Elysee connectors which seem more reasonable and also do a 32mm to 22mm copper connector which could be useful.

2. The standpipe - coming up through the earth (frost/freezing layer) in insulation which I’ll probably put in some waste pipe (like coming into the house) then am I best to plumb in copper, or should I go plastic? I need a double check valve, I know that, what would be your order of connections and material to use?

3. Hot water - I’ve read that I can’t use MDPE for this, how is it done properly? It’s not far from the house, what pipe should I use and how to insulate it?

Ok, many thanks for any advice!!

EDIT: I just did some more research and saw TMVs - is this the way to go for the standpipe and if so which one? We’re coastal so rustproof is really important if poss...

 

[Madrab]

Connectors - what would you recommend? I’ve been looking at JG Speedfit but they are really expensive. I’ve found Elysee connectors which seem more reasonable and also do a 32mm to 22mm copper connector which could be useful.

Best to use the same manufacturer as the pipe as for the inserts and fittings

2. The standpipe - coming up through the earth (frost/freezing layer) in insulation which I’ll probably put in some waste pipe (like coming into the house) then am I best to plumb in copper, or should I go plastic? I need a double check valve, I know that, what would be your order of connections and material to use?

You really want any outside tap supply run and controlled internally, keeps the pipework within the heated envelope and allow it to be shut off in the winter without impacting any other supply (be it in the house or a garage etc) - usual order would be ISO valve/drain off/double check and out to the tap.

 

[oldbutnotdead]

For your outside hot water run i'd veer towards plastic (not MDPE) and do it in one length (long swept bends rather than elbows)- placcie pipe is quite good at not splitting if it freezes but the fittings tend to pop off.
Use twinwall duct, thread the pipes through normal slittable pipe insulation (but don't slit it) then push the insulated pipe through the duct. Make sure you seal the outside end of the duct (so it doesn't fill with water).
I'd suggest you run your cold standpipe from the house rather than teeing off the main- so you can easily isolate it if needed. Again duct it but if you're at watermain depth you could probably skip the insulation except the last 2 metres each end.