Thorfun

Is it not difficult then? Surely the risk of leaking is high for a novice and push fit copper is safer and quicker! Albeit more expensive. But when you take the time to do the soldering in to consideration the money saved on labour balances out the cost of the pushfit fittings?

greetings! I need to plumb in the showers next. we have Hansgrohe iBox with shower select 2 plates feeding a shower hose and a ceiling drencher head. the same setup in 3 showers. my question is around copper or hep2o. most of the pictures of peoples installations done by 'proper' plumbers based in the UK are copper from the iBox to the shower outlets. is there a reason this can't be done is hep2o? or, I guess the better question is, what is the benefit of using copper? or would it be a case of 'we've always done it that way'? if copper from the iBox to the shower outlets is best can I use push fit copper fittings? I'm not sure I want to start learning how to solder copper this far in to my plumbing journey!

+1.

thanks. I started my build so long ago that those regs don't apply! 🤣

when did that come in? I haven't lagged my pipe runs and our BCO didn't mention anything.

Kingspan Optim-R (other makes are available) is a vacuum sealed insulation board that is made to measure. they cannot be cut and if they get nicked by anything then there goes your insulation value. plus they are stupidly expensive. I probably would look down the Aerogel route that @TonyT mentioned.

they definitely do! I used a load of boxes of them on our build. but other makes are available. 😉

It’s what we as self-builders do.

I decided against one to start with as our toilets are flushed from the RWH tank so that shouldn’t affect showers etc. I guess if I find we have pressure issues we can fit one at a later date.

There’s not enough room to bend the plastic pipe out within the stud walls. I’m ok with having a fitting behind the wall at each appliance/sink/basin etc. I have no other joins from plant room to tap so my risk of leaks is greatly reduced. And if there ever is a leak I know where it’ll be.

it's a hang on the wall sink but we're putting a unit of sorts underneath.

not had a biscuit since you threw your toys out of the pram a little while ago. tbh, I don't know the benefit! nor do I know the downside. both copper and hep2o can be dismounted if required so I don't see the difference. only thing I can think of is that copper comes out of the wall straight but it's hard to get plastic to be nice and straight? maybe @Nickfromwales or someone else who actually knows what they're doing can answer your question.

I need to 90° out of the wall so converting to copper is easy as I can push fit it into the 90° hep2o elbow. I don't see the issue here! I see most posts that people come out of the wall in copper and run plastic in the walls. 🤷‍♂️

that's the HRC. if you can tell me how to make that connection NOT inside the wall without having a load of connections under the sink then I'm all ears! I did think about the potential risk of making that connection behind the wall and then figured I'm already putting 90° elbow bends behind the wall to bring the hep2o out so there's already a risk behind the wall. to make that HRC connection outside of the wall I'll have to bring the 15mm hot and the 10mm HRC out through the wall via 90° elbows and then join with the reducing T. all sounds rather messy.

small black pipe is condensate pipe from an AC unit. 18mm ply fitted within the studs for fitting the basin to. that's also on tomorrow's list of things to do!

decided to stick with 32mm as suggested by @joe90 and given the go-ahead by @Nickfromwales! this is my first attempt at a basin waste and pipework and this room will be boarded Monday so if anyone can see any issues then please tell me now! I wasn't sure where to bring the copper out for the taps but there'll be a cupboard under the sink eventually so figured it didn't really matter? on to the toilet waste as toilet water pipe tomorrow.

Sure can! It’s a great way to save money. if anyone questions it just call it landscaping.

Problem is it’s a very small room already and losing an extra 18mm will make a difference. I could add the ply between the studs though so as to not lose any room size.

But how will taking nearly 50% of the timber width affect the structure of the wall? That’s my concern.

next question which is related to the previous discussion on upsizing waste pipe. i know that @Nickfromwales is a big advocate of doing this, so for a wc basin the waste pipe would be upsized from 32mm to 40mm. but in our downstairs WC i will have to drill holes through the internal stud wall to run the waste pipe. it is 89mm CLS and so if i'm drilling a 45mm hole (to account for the fall of the pipe) through the 89mm CLS that's quite a fair chunk of the timber missing! is this an issue? should i just stick with 32mm in this situation? the waste run is about 1m at most from basin to soil stack.

our target was 1ACH. our house is much more complicated that a basic rectangle and we spent a lot of time taping windows and membrane around attic trusses and fitting Tony trays etc. we ended up with a score of 0.98ACH@50Pa and were very happy. we know we could've got it lower if we had the time (and a diy blower to keep testing with) but as we'd already hit my target i was happy to leave it there. so 1ACH is very achievable doing it DIY.

is your house actually being run on all 3 phases? we have a 3-phase supply but i decided to reduce complexity to just run the house on a single phase and run 3-phase cable to the garage where the EV chargers will be just in case i decide to go 3-phase charging. Our PV is run off a single 10kW Single phase inverter (the same phase that the house runs on) again to reduce complexity and our battery storage is also on that same phase. IF i ever need 3-phase then by that time hopefully 3-phase smart meters will be more readily available and it can be configured for net metering as @joth mentions above and then it doesn't matter if i draw on the 2 phases that don't have PV on them as any excess generated that is sent to the grid will offset any draw from the grid on the other 2 phases.

this subject has been debated quite a bit on here and i don't think there is a perfect solution! you could absolutely go overboard with insulation, resilient bars, soundbloc etc but then you need a gap at the bottom of the door to let air in/out for the MVHR! so sound will escape that way. in the end we decided to use resilient bars in certain places where we wanted to reduce the sound transfer, e.g between my study and the kid's bedroom above and we used 100mm Rockwool in the ceilings between the joists and 50mm on internal walls. we haven't used soundbloc anywhere and are using 12.5mm standard plasterboard. was that a good choice? ask me again once we've actually finished building and have lived there for a while! my conclusion was that we'd never eliminate the transfer of sound without spending a lot of money and detailing every wall to ceiling to floor junction with sound sealant etc so we just tried to take the edge of it all.

we filled our 89mm studs with 50mm Rockwool as well. no issues with the cabling that our sparky mentioned. I presume it's because the cables are running in the insulation but rather sat on top like this photo but maybe @ProDave can give a definitive answer?

Seriously? Why bother? Save your time and money!! It’s already insulated and airtight to passive house standards. Any additional insulation will give very little gain I would’ve thought. Plus you’ll likely have to uprate your electrical cables as they’ll be running through insulation.