First fix pipe size?

[Luggsey]

Hi, I'm about to pipe up my upstairs cold water to sinks and showers.
It's a large 4 bed house, stopcock in the kitchen, middle of house outside wall, presently with 25mm pipe into a tap for building water.
So upstairs sinks and showers are piped with tails hanging down in 15mm JG speedfit. Supply pipe will be in ground floor ceilings.
So decision time, what's best practice?
Do I continue with 25mm pipe and T off at each tap with 25-15mm T?
Do I send one 25mm pipe to one side of the house and another to the other side or do I run one pipe and T off where needed?
I would like to avoid lowering the pressure too much if two taps are in use, it's an old farm at the end of a long main at 6 bar but not massive flow.
Finally whats the best practice way to clip pipes above a ceiling, is there a standard pipe clip distance?
Cheers all.

 

[ShaunCorbs]

How many bathrooms/ en-suites

also any reason your doing it yourself and not hiring a plumber ?

 

[Luggsey]

Hi, three showers upstairs and one downstairs.
Plumber=Money=Run out!

 

[ShaunCorbs]

Planning on using more than one at the same time? 28mm should be fine

 

[Luggsey]

Planning on using more than one at the same time? 28mm should be fine

I keep saying 25mm pipe and it's 22mm! Im a sparks so always think 20/25mm pipe...
20 'if' 22mm is ok? Do I need to run a seperate pipe to either side of the house or simply T off from a single 22mm ?

 

[ShaunCorbs]

Would tee off for each but also depending on length I would install a secondary return circuit in mlcp

 

[Luggsey]

Would tee off for each but also depending on length I would install a secondary return circuit in mlcp

I have a Grundfos 'comfort' pump for the hot water, is that what you mean? Why the MLCP pipe?
Cherrs.

 

[ShaunCorbs]

Because you can’t use speedfit or hep or any plastic on a secondary return circuit

 

[Luggsey]

Because you can’t use speedfit or hep or any plastic on a secondary return circuit

Can you elaborate for me?
Is it to do with excess heat?

 

[ShaunCorbs]

And the oxygen in the water will break down the plastic pipe

 

[Luggsey]

Thank you, I remember the pump had to be a bronze impller to combat that. Can I use copper teturn or will that suffer from oxidation or whatever process causes problems?

 

[ShaunCorbs]

Copper or mlcp are the only ones approved

 

[Luggsey]

Copper or mlcp are the only ones approved

I planned to fit the pump next to the tank it returns to making the return run only short. Does that sound ok?

 

[ShaunCorbs]

Yep that sounds ok with either copper or mlcp