Property renovation, re-plumb advice req`d

[Steve]

Hello, first post and i`m looking for a bit of advice please.

I have recently bought a 3 bed end terrace, and i`m going to be gutting it and completely re-plumbing it to replace the lead pipes, inc new boiler, and i`m moving the bathroom around.

I`m an engineer and decided to do as many of the jobs in this project as I can. Best way to learn, would just like some guidance and sound out some of my ideas with the pro`s.

From where the water enters my property which will be with mdpe, then a stop tap, am I correct in thinking that this converts to 22mm pipe?

If so I was thinking to reduce the pressure drops with multiple water demands, I would plumb 22mm pipe to the main areas (kitchen, bathroom & C boiler) then convert via manifold in each room to 15mm for the respective components, is this the norm? and will it solve the problem of pressure drops?

Any help tips and advice would be greatly appreciated.

Cheers

 

[Steve]

Sorry, I will try to make myself clearer...

Off the 25mm mdpe i was going to have 3x 22mm pipes, on to the kitchen, one to the bathroom and one to the boiler.

Off each of these pipes in the kitchen and bathroom i was going to have a 22mm manifold with 15mm outlets.

Off the bathroom manifold 15mm outlets i would supply toilet, sink, shower and bath. Kitchen manifold would supply sink, washing machine etc.

Is this a stupid way of doing it? I just thought if I could get a greater of volume of water to that area it would avoid pressure drops?

 

[plum ber]

I have done this before aswell and it worked really well it was in a bathroom but neat and tidy if ever I go back to the job isolation is really quick and easy I will try and find a pic also

 

[Best]

Sorry, I will try to make myself clearer...

Off the 25mm mdpe i was going to have 3x 22mm pipes, on to the kitchen, one to the bathroom and one to the boiler.

Off each of these pipes in the kitchen and bathroom i was going to have a 22mm manifold with 15mm outlets.

Off the bathroom manifold 15mm outlets i would supply toilet, sink, shower and bath. Kitchen manifold would supply sink, washing machine etc.

Is this a stupid way of doing it? I just thought if I could get a greater of volume of water to that area it would avoid pressure drops?

Just need to come off stopcock in 22mm & keep going to each main point in 22mm, then tee down to 15mm to small supplies like toilets & basins.

 

[Gray0689]

No mate sounds good
But you could just go to a central point ie hot press and do your manifold from there

 

[plum ber]

Just need to come off stopcock in 22mm & keep going to each main point in 22mm, then tee down to 15mm to small supplies like toilets & basins.

but there is nothing wrong with running into the room in 22mm then into a manifold and split from there for the various appliances ie in bathroom behind the bath, then all you have to do is whip off the bath panel to isolate every appliance individually??

 

[Best]

but there is nothing wrong with running into the room in 22mm then into a manifold and split from there for the various appliances ie in bathroom behind the bath, then all you have to do is whip off the bath panel to isolate every appliance individually??

I would be more than happy with each bathroom having it's own isolating valve but take your point. I think any main isolators should be somewhere handy & all labeled as to where they feed.

 

[Steve]

Just need to come off stopcock in 22mm & keep going to each main point in 22mm, then tee down to 15mm to small supplies like toilets & basins.

If I come off the stopcock with 22mm and then split 3 ways wil that not defeat the object of trying to reduce pressure drops?

I was thinking: mdpe (25mm) - stopcock - short 25mm pipe to manifold (25mm in and 3x 22mm outlets) ???

 

[Koogatubac]

Why do you not
View attachment 9280

Is that picture on a 3 bed end terrace property?
I meant i havnt seen a manifold on a 3 bed end terrance property mate

 

[Gray0689]

No mate it's not lol
But no reason it can't be very simple to do and yes will be more expensive in short term but on heating side will be better in long term imho

 

[Best]

If I come off the stopcock with 22mm and then split 3 ways wil that not defeat the object of trying to reduce pressure drops?

I was thinking: mdpe (25mm) - stopcock - short 25mm pipe to manifold (25mm in and 3x 22mm outlets) ???

I know what you are thinking, but to use 25mm pipe to the manifold will make no difference to the flow rates. 25mm is much the same as 22mm copper.

 

[Koogatubac]

No mate it's not lol
But no reason it can't be very simple to do and yes will be more expensive in short term but on heating side will be better in long term imho

you've done cold water distrubution pipes on manifolds have you mate?

Heating via manifolds like that (UFH?) i prefer than radiators

 

[Gray0689]

you've done cold water distrubution pipes on manifolds have you mate?

Heating via manifolds like that (UFH?) i prefer than radiators

Yes mate if you look at that picture the ones in bottom right corner are domestic hot and cold manifolds
The rest are to the radiators
no underfloor heating

 

[JCplumb]

I think that this is being over cooked somewhat. This is a 3 bed terrace not a block of flats Use copper as it's less likely to fail especially if you're hiding it under tiled floors etc. Plastic is good and reliable but ONLY if done right. Whereas if your copper installation isn't leaking on day one, it probably won't be leaking on day 10,000.
15mm everywhere will be fine for hot and cold runs if your incoming main has decent pressure and you're installing a combi/sealed system, manifolds to supply a bathroom are overkill IMO, use ISO's to isolate units. The only reason I would think manifolds were first mentioned is because someone has been looking through the John Guest brochure and thought 'ooh that'll work'

 

[Gray0689]

I think that this is being over cooked somewhat. This is a 3 bed terrace not a block of flats Use copper as it's less likely to fail especially if you're hiding it under tiled floors etc. Plastic is good and reliable but ONLY if done right. Whereas if your copper installation isn't leaking on day one, it probably won't be leaking on day 10,000.
15mm everywhere will be fine for hot and cold runs if your incoming main has decent pressure and you're installing a combi/sealed system, manifolds to supply a bathroom are overkill IMO, use ISO's to isolate units. The only reason I would think manifolds were first mentioned is because someone has been looking through the John Guest brochure and thought 'ooh that'll work'

Nothing is overkill if someone wants it done lol

 

[Koogatubac]

Good work grey