MortarThePoint

The isolation benefit is reason enough to have the manifolds I think

I want to clip my 15mm and 10mm pipes to the underside of the concrete HCF flooring. I'll be using standard pipe insulation that has a 13mm wall. The standard clips, example below, look to leave less than 13mm between the pipe and whatever the clip is mounted on. Can anyone recommend on that is better for this as I don't want to have to kink my pipe for each clip or have the insulation pushing the pipe out of the clip.

An old thread, but a beautiful install and surely a standard to try to match with my own. Another benefit that comes to mind with using an isolating manifold is the possibility of adjusting flow rate to basins etc. What with the required water usage calculations etc, being able to set the flow could help reach a required total without putting restrictors in the pipes themselves or buying expensive taps. Did you add insulation to all the pipes after this photo was taken?

I suspect the top one (angled ply/osb) is easier if I install the insulation at rafter level first

I plan to use sheet VCL (green poly) to make the VCL around the loft room. I have shown it in green in the image below. Battens across the rafters for under rafter insulation (all insulation is mineral wool) provide a surface to staple the VCL to (tape over). I'll have to tape around where the VCL crosses each stud of the dwarf wall which will be a bit tricky, but OK. What I'm less confident of is how I deal with the big transition to wall plate (masonry walls). This is where the green VCL is crossing the 222mm high bottom chord of the trusses. Does anyone know what is normally done here? Just cutting a slot and flaps out of the VCL and stapling/taping feels a bit fragile. It feels like I should have something to support the VCL here. I can see two easy options with ~9mm OSB or 5mm ply. Shown below before and after adding insulation, though maybe the rafter insulation would carry on down before adding any sheet due to restricted access. In the top otption, the ply/OSB could be screwed in place and then sealed with Passive Purple meaning that the VCL itself wouldn't need to go down all the way, but may as well. Very time consuming though.

I was more thinking that my suggestion of a mixture of stripwood on the face of the studs and fewer sister studs would mess with centres, but it looks like there are some doubles etc anyway.

A bit of pocking around and I have found some (up to 4 way): https://www.jtmplumbing.co.uk/pipe-fittings-c433/hep2o-pipe-fittings-underfloor-heating-c999/hep2o-brass-manifolds-c661/hep2o-four-port-valved-manifold-15-tm-tf-fp-p21691/s27296

You could put strip would on each stud that doesn't have a strap and screw timber to the side of each stud that does have a strap. The problem with that though is it would ruin your centre to centre distances if they are already good.

Need to add appliances: washing machine, dishwasher and option for fridge

Interesting I hadn't seen that system before.

I'd like that. I haven't seen a Hep2O manifold that can do that yet, but maybe it's less widely carried that 5he simple non-isolating manifolds.

I thought I'd start a thread of considerations to do with the plumbing. Below are some pictures that show the proposed layout. I'm presuming that I'll use 15mm for all pipes except those shown as 10mm and probably the stopcock to Water Cyclinder will be 22mm (inc manifold) --------------- -------------------

Here's an important one from the Hep2O FAQ: Q.) Can we use expanding foam on Hep2O? A.) No, due to the chemicals when in its liquid form, these could harm the pipe. Once the expanding foam has cured Hep2O pipe can be safely fed through it. Alternatively the Hep2O could be sleeved to give the required protection. https://plumbpal.co.uk/image/catalog/Documents/Hep2O_FAQs.pdf

My volume figures were wrong (school boy Maths error): Q.) How much water does Hep2O pipe hold per metre? A.) 10mm pipe = 32ml 15mm pipe = 110ml 16mm pipe = 120ml 22mm pipe = 260ml 28mm pipe= 400ml

@Nickfromwales or @Conor : sorry for the basic question, but do you do a 15mm feed all the way back to the mains supply or do you do 22mm to the room and then 15mm / 10mm to the various places in the room?

I think I understand. I was thinking it is to reduce dead volume before hot comes through, but is it to create a more restrictive path than that to the bath so the bath doesn't suffer a loss of pressure?

Good point, skinny pipes to basins for faster hot water (0.35l/m vs 1.00l/m, but more constricted). I presume HRC is a looped system that makes for instant hot water which isn't what we'll have. As this basin is about 6m from the cylinder I'll probably have a dedicated pipe for it as then it can be 10mm all the way, unless you'd be happy with 10mm for a bath feed?

The stated diameter is the OD of the pipe, so if you come across the image below ignore it. I double checked with Wavin technical. Some IDs are: OD ID Area or volume/metre 10mm 6.7mm 0.35cm2 or l/m 15mm 11.3mm 1.00cm2 of l/m 22mm 17.7mm 2.46cm2 or l/m

Here's some information about Hep2O pipe pressure and temperature. This old document has some pipe dimensions in: https://www.hep2o.com.au/downloads/Hep2o_Parts_Users_Guide_Australia_2018.pdf Here's the installation guide: F-47058-0.pdf Here's link to a performance sheet: http://www.tglynes.co.uk/downloads/tgl-coshh-tech-hep20-performance.pdf

Sounds good. When I did the UFH pressure test we had 5.5bar so will hopefully be good for water pressure. I guess we'll use 15mm allround then for water feed (not UFH), thanks for sharing the insight. Looks like you had some good service gaps in your concrete floors, but I can see some pipes coming through the concrete into the floor channel of the wall. What size holes did you use in the concrete? Did you bother sleeving the pipes as they passed through, or just filled with foam? Similarly, what did you do when passing through blockwork walls?

I'm intrigued by your mixture of water pipe sizes. You appear to have thinner and thicker water pipes. I am currently planning my plumbing so it would be good to understand.

It's our main bedroom en-suite so high likelihood of basin and/or toilet being used at same time as shower. (and yes that second bit horrifies me too).

I didn't like the sound of the extra 16seconds of wasted hot water so have punched a hole in the sole plate of the wall and the hollowcore concrete, below the word SHOWER, and the hot water feed can come up through there. I now wonder if the cold should come up there too as will turning the basin tap on affect the shower temperature?

I'm trying to plan the plumbing of the en-suite. Thanks to @Nickfromwales I know what to do with my basin waste and I show that it brown and black below (brown in the room, black is in the wall). I then need to route the hot and cold water feed (shown combined as red below) around the room to the various places. It's going to come in to the room in the corner where there is a trench in the screed along the top wall to the bath. It's going to then have to come above screed to reach the right stud wall before feeding the basins and continuing on to feed the shower. The shower and bath wastes have holes in the floor underneath the shower and bath. The feed may pop up under the bath rather than the corner, but that doesn't change much. Where a right angle is shown in pipe below there may need to be an elbow or tee. Is it a good idea to clip the fed pipes to the OSB or does that make it noisy? I am expecting to use something like push fit JG SpeedFit for the water feed, but am solvent welding the wastes. The length of pipe round the room is about 12m so if it's 15mm OD / 11.5mm ID (JG Speedfit pipe datasheet) the pipe volume is about 1.2litres. A shower running and 6l/m total and 3l/m each of hot and cold would take 24 seconds to pass that volume through. It's a bit of a shame because if I could get there direct it would only take about 4m of pipe and so take 8 seconds for the shower to heat up. Is 15mm the correct size to use to feed a shower? Bathroom wall layouts as viewed from outside the room:

We aren't considering any particularly fancy tiles so weight probably not a concern. Do you think it reduces the bond strength of the tiles to plaster though? I'm just thinking it is easier to ask he plasterer to do a whole room that mark out where he shouldn't plaster.