1st fix question...22mm/15mm

[r6deano]

Afternoon all!

Need to start 1st soon on my renovation on my bungalow - currently constructing some stud walls and plasterboarding in the bathroom/ensuite areas. They are adjacent to one another and both of them have a wall that backs onto the loft area where the cylinder will be.

I wanted to run my plastic from where the taps etc will be thru this wall and label them so the plumber can hook them up....but would like to know the rule of thumb when it comes to when 22mm pipe should change to 15mm....my cousin tells me run 22mm as far as you can go and tee off last-minute ....
So would I
A) run 15mm everywhere in the bathrooms and once it penetrated the wall into the loft, the plumber will take over with 22mm

B) take 22mm all the way to the location of the fitting, and just 15mm the final 500-1000mm

C) something different?!

TIA guys !

 

[terryplumb]

is the plumbing gravity fed hot and cold ,or is it a pressurised unvented hot water cylinder and cold from mains ?

 

[r6deano]

is the plumbing gravity fed hot and cold ,or is it a pressurised unvented hot water cylinder and cold from mains ?

It will be the latter Terry, mains pressure 300L UV cylinder. And yes, cold from mains.

Ty

 

[terryplumb]

then you need to speak to the plumber ,who is responsible for the installation. who incidentally has to have a special qualification G3 for this type of work. he may be happy with 15 mm all the way. especially if you have no bath.does he know you are doing some of the work ?

 

[r6deano]

then you need to speak to the plumber ,who is responsible for the installation. who incidentally has to have a special qualification G3 for this type of work. he may be happy with 15 mm all the way. especially if you have no bath.does he know you are doing some of the work ?

I'm waiting for him to get back to me with his availability and I was planning to be his mate on the fix, just wanted to run the pipe behind the plasterboard and have it run to final location, it's possible that it will be a couple of continuous lengths of piping barring one elbow, so I was hoping to run that without him.

There is a bath in the main wc, I wasn't sure on the significance of larger piping IE 22/28mm, I didn't want to run 15mm then be told for flow reasons I should have kept larger for longer...

Ty

 

[dilalio]

22mm for a bath (even if you don't want one) think of the next occupiers. 15mm should be ok for everything else.
Unless you have massive shower outlets with large flow capacity. But then your overall supplied flow rate is in question.

 

[r6deano]

22mm for a bath (even if you don't want one) think of the next occupiers. 15mm should be ok for everything else.
Unless you have massive shower outlets with large flow capacity. But then your overall supplied flow rate is in question.

Mains pressure isn't great....yet to have dynamic flow test yet though. My back up plan is a Grundfos home booster if the shower is pathetic...!

 

[dilalio]

There are pipe sizing guides and methods online that show you how to calculate the supply sizes and runs based on the loading of each outlet.

 

[Hot&Cold]

I'm waiting for him to get back to me with his availability and I was planning to be his mate on the fix

Many plumbers/trades people prefer working on their own and have their own way of working.Some hate the idea of the customer helping or being in close proximity but some may like it.

Sometimes its best to let the trades people do their job unhindered and just supply refreshments on a regular basis, getting progress updates at the same time