MortarThePoint

Guessing that the lambda value of these sorts of tapes is similar to EPS or Mineral Wool which is 0.03 W/mK. a 15mm wide strip would have a U-valve of 0.03/0.015 = 2W/m2k so may be some value in going wider, but the frame would trap air pockets as well which are similar to the chambers in the frame itself. The https://www.expandingfoamtape.co.uk/ stuff is vapour permeable which supposedly reduces condensation, not sure how though.

Thinking about the ORANGE tape, there are two other obvious options below. It could contribute to air tightness, but ultimately the cavity closer also needs to be sealed to the blockwork which obviously can't be achieved by any tape on the frame. Make it wider: Move it to where there is another 'pocket' which I think is for the fixing lugs:

I am a little unsure which width of tape to use. Thickness is fine and to match the tolerance allowed around the frame, but how wide should the tape be? Seems little point for it to be full frame width (~100mm) as all the weather based action is on the outside. Below is a section of our frame (Residence 9) and I have mocked up some outer leaf brickwork and the cavity closer and inner leaf blockwork. To Seal I have added the following: RED: 15mm width (5-12) expanding foam tape between two 'hooks' of the extrusion. This forms the weather seal ORANGE: (optional?) 15mm width (or wider?) (4-9) expanding foam tape (extra insulation?) PURPLE: Passive Purple airtightness paint or alternatively an airtightness tape CREAM: Wet skim plaster Cavity is filled with blown beads insulation.

Looks promising as the pressure has ticked up a bit to 4.0bar. Another beer chilling in the fridge.

Thanks. It's holding steady at around 3.3bar so I'm going to give it a few hours before I do anything.

A little bit I guess. I didn't read it, I should check. Maybe 5C lower temperature.

This is a concern. Pressure vs time 0 5.2bar 1hour 5.4bar 2hours 5.2bar 3hours 5.0bar 14hours 3.3bar That feels like too much pressure drop for it to be 'stabilisation'. I've run my fingers over all the manifold connections and they are dry. I guess my next step is repressurise and to start closing loops. Does anyone know if the flow and actuator valves are pressure tight? If not that approach won't work. I haven't used any PTFE tape anywhere.

Feels like it sometimes ? Pressure still holding after 1 hour. Cold beer opened. It's been a long week (>80 hours) PS: don't ask why that loop looks so drunk. I had to cram in an extra pass at the edge of the room.

Two holes drilled, one exciting moment Pressure holding so far Beer chilling ?

Just started my pressure test. Fingers crossed! I'm off to drill some holes near the UFH pipes now

Do you mean on a different floor (GF Vs FF)? If so, no each manifold serves one floor only

Excellent, Amazon order going in and I'll see if they have some ratchet mole grips for my UFH manifold work.

Thanks Nick. It's always difficult to know what's important good practice and what's good practice according to people who sit in an office and write documents. There are various sources that say to use expansion sleeves (e.g. LABC, Underfloor Heating Trade Supplies) but on site practice is a more useful guide in many cases. The main downsides of having them are the installation faff and the increased depth of screed to cover a thicker item. I sent the image to the installer and he said fine as long as has the minimum cover. I've decided I'll leave them in as they are where the screed needs to be thicker due to hollowcore camber anyway. There is one place where this isn't true, and I'll remove them from there. I was assuming the screed would be too porridge like to flow in. Pure water would, but will the screed really flow into a 300mm long 3mm wide channel? I've no zones which are particularly far from the manifold. The furthest is probably about 4m upstairs so hopefully that will be fine.

Just spotted the bum bags in the video. The Rock would approve:

@Nickfromwales and @Russell griffiths Sorry to tap you up on this but you've normally got a good view on all this. I'm about to attach my eurocones so removing these after that would be tricky.

Are these good? Looks like I'd need two lots of 2pc to have the four required: https://www.amazon.co.uk/gp/product/B07RVJ1LF3 They don't make videos like this anymore:

Has anyone tried this: https://www.expandingfoamtape.co.uk/ It's around £2.24/m for 20mm wide, 5-12 thick

In this installation video from Cemfloor about expansion joints, they haven't added any sleeves at the joints, but I do notice that what I presume is the Flow pipe has conduit around it for a long distance. Insulation I guess. https://cemfloor.co.uk/training/ STEP 3

I'm going for Cemfloor Therm and the installer said he puts pieces of plywood in the doorways to encourage localised crack. I had already started installing 'pipe expansion sleeves' aka 25mm flexible conduit in the doorways and he said not to bother. Magnus Magnuson, I did it in all doorways. You can see an example below, a bit difficult as it's white. I put them on the pipe as laid, so unless I forgot and added later, they don't have skits along their length making removal difficult. Is this a mistake, should I remove them all? Screed is going in at 50mm nominal and needs 25mm over pipes which it would achieve over these unless the float up slightly.

What NHBC call Serpentine achieves the same by meandering out at twice the spacing and the returning in the gap left.

According to NHBC it's linear pattern not serpentine. Anyway, one continuous meandering from one side of an area to the other.

As we are using 150mm pipe spacing (ASHP) most rooms end up as two loops. Typically theses are laid at right angles to the wall with a window. Serpentine pattern. How should the two loops have their flow and return chosen. Options: 1. Both loops flow to middle of room, return from edge of room. Cosiest in middle of room, but does it concentrate too much heat there? 2. Both loops flow to outside of room 3. Keep same flow direction, one loop flows to outside first, second to middle first. I think I've seen this in some Google search results. 4. Doesn't matter a jot About to cut my loops onto the manifold so want to get it right.

Not in yet so it's an option to reinforce if I can get some in time

This is what it would end up looking like The gap highlighted would probably be around 5mm, but could end up being more. I'd be surprised if it's an issue for carpet or timber flooring even at 20mm. Tiles may be more of an issue, but perhaps that needs to be. @Nickfromwales and @Russell griffiths you're talking about reinforcing with mesh where I have shown the green squiggle. I can't see it cracking there unless the HCF and UC beam move differentially and if that occurs do I want the screed to fight it? It would be worse for the screed to crack somewhere else.

If not using chicken wire, what's the best bet. Anything available from Toolstation/Screwfix?