My self-build DIY plumbing

[Thorfun]

as I near the finish of the internal soil pipes (for now at least) my thoughts are now on the water pipes. I have decided to go with the radial manifold system. our toilets and washing machine will be supplied by a RWH header tank from the loft so they're not part of this plan but I am planning on putting a manifold in the loft to allow each toilet to be isolated individually if required.

 

Below are some screenshots of what I think I need but I have a few questions (btw, ignore any pipe sizes you might be able to see, I just couldn't be bothered to remove them and the software I used ignored my request for metric sizes anyway!).

 

In the master bedroom en-suite, we're having his and hers sinks. is it really worth having separate pipes for each sink or should I just run both of the same hot and cold?

 

In the studio it is a small and rarely used en-suite and so I figure I might as well just run a single hot and cold feed and run both the shower and sink of that. madness or justified?. it's also quite a long distance from the plant room (15m - 20m or so) so I presume it'll need an HRC?

 

Any of the other runs need an HRC? or should I just put one in regardless as it's a sensible thing to do even if our dead legs are minimal?

 

In the kitchen we'll have a Quooker under the sink. I've just got the single cold feed for the kitchen sink and Quooker as I see no reason to have the Quooker on it's own feed especially as they're in the same location. is that sensible or should I run a dedicated feed for the Quooker?

 

think that's it for questions for now. any other comments?

 

Ground Floor

 

First Floor

 

Studio above garage

 

 

[Pocster]

1 hour ago, Thorfun said:

as I near the finish of the internal soil pipes (for now at least) my thoughts are now on the water pipes. I have decided to go with the radial manifold system. our toilets and washing machine will be supplied by a RWH header tank from the loft so they're not part of this plan but I am planning on putting a manifold in the loft to allow each toilet to be isolated individually if required.

 

Below are some screenshots of what I think I need but I have a few questions (btw, ignore any pipe sizes you might be able to see, I just couldn't be bothered to remove them and the software I used ignored my request for metric sizes anyway!).

 

In the master bedroom en-suite, we're having his and hers sinks. is it really worth having separate pipes for each sink or should I just run both of the same hot and cold?

 

In the studio it is a small and rarely used en-suite and so I figure I might as well just run a single hot and cold feed and run both the shower and sink of that. madness or justified?. it's also quite a long distance from the plant room (15m - 20m or so) so I presume it'll need an HRC?

 

Any of the other runs need an HRC? or should I just put one in regardless as it's a sensible thing to do even if our dead legs are minimal?

 

In the kitchen we'll have a Quooker under the sink. I've just got the single cold feed for the kitchen sink and Quooker as I see no reason to have the Quooker on it's own feed especially as they're in the same location. is that sensible or should I run a dedicated feed for the Quooker?

 

think that's it for questions for now. any other comments?

 

Ground Floor

 

First Floor

 

Studio above garage

 

 

My view on this is simple . Had a manifold of manifolds and run a pipe to every outlet . My backs (expletive deleted)ed so I can think of nothing worse to getting under a sink etc. to isolate it . It costs more in pipework ( but less in fittings if you just let the pipe ‘ go where it wants ‘ . 
For me to isolate in 1 place is fantastic - and I use this facility easily .

I’ve just added an outdoor sink and broke my own rule ; branched off the kitchen hot and cold - it just wasn’t worth the effort of 2 new feeds .

So in hindsight; an ensuite for example could just be 1 hot / cold feed rather than be a feed for each outlet I suppose . I guess it depends as well if you are living on a building site ( like I am ) ; the convenience of isolating each thing is great .  

[Thorfun]

2 minutes ago, pocster said:

My view on this is simple . Had a manifold of manifolds and run a pipe to every outlet . My backs (expletive deleted)ed so I can think of nothing worse to getting under a sink etc. to isolate it . It costs more in pipework ( but less in fittings if you just let the pipe ‘ go where it wants ‘ . 
For me to isolate in 1 place is fantastic - and I use this facility easily .

I’ve just added an outdoor sink and broke my own rule ; branched off the kitchen hot and cold - it just wasn’t worth the effort of 2 new feeds .

So in hindsight; an ensuite for example could just be 1 hot / cold feed rather than be a feed for each outlet I suppose . I guess it depends as well if you are living on a building site ( like I am ) ; the convenience of isolating each thing is great .  

hopefully the house will be 'mostly' finished before we move in so won't really have a need day 1 to isolate, but the studio en-suite most likely won't be finished so will need to isolate that. I do love the idea of radial plumbing and the single point of isolation sounds great.

 

just looking at those plans and looking at all those pipe runs it brought it all home as to actually how many pipes that is! which is why I was thinking for the his/hers sinks we could isolate the pair from the manifold to save running an extra 2 x pipes. but, I think I'll probably just run them anyway. 

[Thorfun]

ps. I have considered a hybrid version of two pipes to each room from a manifold and teeing off to each appliance from there. but, as you say, adds more in fittings even though it reduces pipe usage. but also adds joins which I'd like to get away from!

[Pocster]

33 minutes ago, Thorfun said:

ps. I have considered a hybrid version of two pipes to each room from a manifold and teeing off to each appliance from there. but, as you say, adds more in fittings even though it reduces pipe usage. but also adds joins which I'd like to get away from!

I guess it depends if you can get to those joins in the event of an issue . 95% of mine I can . But ; I’ve yet to have a Hep2o fitting fail !

[Onoff]

5 minutes ago, pocster said:

I guess it depends if you can get to those joins in the event of an issue . 95% of mine I can . But ; I’ve yet to have a Hep2o fitting fail !

 

Are you alright mate? That's two posts in a row, concise, informative and free from smut.

[Thorfun]

1 minute ago, Onoff said:

 

Are you alright mate? That's two posts in a row, concise, informative and free from smut.

I bring out the best in people. 

[Pocster]

1 minute ago, Onoff said:

 

Are you alright mate? That's two posts in a row, concise, informative and free from smut.

Cheeky (expletive deleted)ing useless counting twat mother (expletive deleted)er slit (expletive deleted)ing shite basted chicken licking (expletive deleted) 

[Onoff]

5 minutes ago, pocster said:

Cheeky (expletive deleted)ing useless counting twat mother (expletive deleted)er slit (expletive deleted)ing shite basted chicken licking (expletive deleted) 

 

Abnormal service is resumed! 👍

 

I wish now I'd run a separate return from the basin hots. Could have had a bronze pump and "instant" hot, triggered maybe by occupancy switches.

[Nickfromwales]

26 minutes ago, pocster said:

Cheeky (expletive deleted)ing useless counting twat mother (expletive deleted)er slit (expletive deleted)ing shite basted chicken licking (expletive deleted) 

we'll need a high pressure 22mm feed to wash your mouth out, young man!

 

 

 

 

 

 

 

 

 

 

 

(expletive deleted)ing penis.  

Edited October 20, 2022 by Nickfromwales

[Thorfun]

On 05/10/2022 at 09:54, PeterW said:

when you are running Hep2O pipe, drill any holes oversize and sleeve with either overflow pipe (21mm) for 15mm pipe or 32mm waste for 22mm pipe runs. It stops you scoring the pipe and creating potential joint weeps. If you’ve got metal web joists you can just zip tie the short sections on to the webs. 

qq on this subject. I have a lot of 20mm electrical conduit lying around. can I use that for 15mm pipe?

 

according to this question on the SF page for it

 

 

so that will give an 18.2mm ID. a bit tight for 15mm hep2o pipe or should it fit like a glove?

[crispy_wafer]

Personally, I don't think that would be an issue, if it all fits, and you can push/pull through without bother and it stops the pipes being scratched/scored when pulling through something abrasive then all good.  maybe the quote is coming from the angle that when doing plumbing you are likely to have excess or offcuts of plumbing waste pipes to hand so that's what's used at the time as conduit.

[Thorfun]

12 minutes ago, crispy_wafer said:

maybe the quote is coming from the angle that when doing plumbing you are likely to have excess or offcuts of plumbing waste pipes to hand so that's what's used at the time as conduit.

yeah, makes sense. and I guess that once I've run out of the excess 20mm electrical conduit I can get some 21.5mm overflow pipe. 🙂 

[Onoff]

I've put 15mm pipe in galv conduit before. Coming down in the corner of a wall. As a nod to mechanical protection:

 

[Jenki]

11 hours ago, Thorfun said:

qq on this subject. I have a lot of 20mm electrical conduit lying around. can I use that for 15mm pipe?

 

according to this question on the SF page for it

 

 

so that will give an 18.2mm ID. a bit tight for 15mm hep2o pipe or should it fit like a glove?

It's just a sleeve so yes id it fits👍

[Nickfromwales]

The biggest killer of pushfit pipe is linear scratches caused by pulling long lengths in through cut various cut / drilled holes and notches which are sharp / abrasive / or worst, have a nail or screw in that you've not seen.

Pushfit fittings rely on the outside surface to create the water-tight seal, so be very careful to preserve this during 1st fix.

[Thorfun]

another question.....pipe lagging with hep2o. is it really worth it in a well insulated airtight property? I'm aware that the first 1m or so from the UVC needs to be lagged and will be and my pipes from the ASHP to UVC will be lagged for their entire run but taps/sinks/showers/baths?

 

ps. I know this subject has been done to death on here but, from my reading, there's still some fore and some against! what's a beginner to do if the experienced ones can't decide?

Edited October 22, 2022 by Thorfun

[joe90]

Well I didn’t bother, insulation only slows heating loss and if usage is not very often then not worth it IMO.

[Nickfromwales]

21 minutes ago, Thorfun said:

another question.....pipe lagging with hep2o. is it really worth it in a well insulated airtight property? I'm aware that the first 1m or so from the UVC needs to be lagged and will be and my pipes from the ASHP to UVC will be lagged for their entire run but taps/sinks/showers/baths?

 

ps. I know this subject has been done to death on here but, from my reading, there's still some fore and some against! what's a beginner to do if the experienced ones can't decide?

I only consider condensation on the cold ( far worse in winter ) an issue, so insulate the cold runs if I think there’s going to be any chance of a problem.

For the cost, it’s something I’d go for tbh. 
On the hot runs, waste of time afaic, unless you’re running an HRC. 

[Thorfun]

1 minute ago, Nickfromwales said:

I only consider condensation on the cold ( far worse in winter ) an issue, so insulate the cold runs if I think there’s going to be any chance of a problem.

For the cost, it’s something I’d go for tbh. 
On the hot runs, waste of time afaic, unless you’re running an HRC. 

that's interesting. I thought it was more likely to insulate the hots and not the colds! how would you know if there's going to be a chance of condensation though? is that experience or some mathematical calculation?

 

I was planning on running 10mm HRC (that'll be a subject of another post after I've done the research) to the wash basins and sinks. I've read previous posts from you that say to run the hot and HRC in the same piece of insulation so that was what I was thinking of doing. so, I guess if I'm doing that for those then it's a small step to just insulating the whole damn lot?

[joe90]

HRC? (Hot return cct 🤔) I know my hot runs are fairly short but 10mm to basins give hot water in seconds.

[Thorfun]

Just now, joe90 said:

HRC? (Hot return cct 🤔) I know my hot runs are fairly short but 10mm to basins give hot water in seconds.

I'm kind of thinking of taking the 'better safe than sorry' approach to my DIY plumbing!

[Thorfun]

7 minutes ago, Nickfromwales said:

I only consider condensation on the cold ( far worse in winter ) an issue, so insulate the cold runs if I think there’s going to be any chance of a problem.

For the cost, it’s something I’d go for tbh. 

if I did decide to insulate the colds then what size wall thickness of Armaflex would I be looking at? would it just be the 9mm to give basic insulation? or would a thicker wall be required?

[TonyT]

I would use whatever thickness is suitable for the clips you plan to install so you can get the maximum insulation without making the installation ridiculously difficult.

 

I would use climaflex inside.

[Nickfromwales]

39 minutes ago, Thorfun said:

I'm kind of thinking of taking the 'better safe than sorry' approach to my DIY plumbing!

100%. 
I am now fully committed to using local PIR’s to activate the HRC pump. I also use the same PIR’s ( via a luxury sensor ) to trigger Pee lighting after sundown ( dusk to dawn ). Two birds one stone.
Top of the kitchen plinth is where I install a stealthy sub-miniature PIR for HRC at the kitchen, with the sensor about the size of a £1 coin.