MortarThePoint

The screed is in and looks awesome to me. The pressure rose and I let a bit out (into the capped off end of an isolation valve). My gauge only goes up to 6bar and It maxed out during the pour having started at around 4bar. I'd guess it got up to 7 or 8 bar, but that's a guess. Back down now. I'm really impressed with how flat and level it is. I've put my 2m level down in a number of places and can't see any real gap under it. There are a very small number of bumps that are kind of like a piece of aggregate causing a 1-2mm hump about 5mm wide. I'm sure those are super easily sorted and I'm pleased. Thanks for the help getting ready for it ?

Different people seem to interchangeably call them fixing lugs, fixing cleat, fixing clips and fixing straps, but they all seem to be the same thing which is a piece of metal clipped and/or screwed to the side/bottom/top of the frame which then gets screwed to the structural reveal. One installer I spoke to thought the standard ones (1mm to 1.5mm thick) weren't substantial enough so uses 3mm joist straps which he cuts to size. I digress. It's obvious how you pack a frame when you are using the 'screw through frame' mounting method, but how do you do it when you are using fixing lugs? Do you just squeeze them in and then silicone them in place? I have Cavalok cavity closers so the windows sit mostly over that, with perhaps 15-20mm extending out exterior of that. That 15-20mm is where the Compriband TP600 / Bloco 600 / EXP6 is going to form my weather seal. So ultimately the packers need to go between the window frame and the Cavalok cavity closer. Hmm, hope there isn't too much movement to the Cavaloks! Should I use a glazing shovel to pry the gap open slightly and squeeze the a packer in? Frame packers are different to gazing packers as they are U-shaped designed to go around the through frame screw. That seems less relevant when the screw is elsewhere.

I think I have a candidate for option 3: https://www.toolstation.com/corner-brace/p43669?utm_medium=feed Put in at ~300mm centres they would provide vertical support to the cavity closer. These windows are about 10kg per 300mm so that's quite a load. The inner leaf would take about half that, so each of these would need to be holding up 5kg through a single screw hole (lower one will be below cavity closer). More expensive alternative that my not be quite high enough but has more holes: https://www.toolstation.com/galvanised-angle-plate/p98602

Here are some photos to help see the issue. The first is only 620mm wide so not much of an issue. Being a lighter window and not much distance to the Cavalok cavity closer's corner it won't twist much. Packers at the bottom near the corners and packers + fixing lugs at the sides, job done. The second photo is more of an issue, 1800mm wide. Cavity closer isn't so stiff against twist at the centre is far from corners. Packers at the bottom near the middle will twist the closer outwards. Solutions I've thought of so far: Put temporary blocks (wood) under cavity closer to support against twist until creasing tiles added later Screw top of window frame to underside of steel lintel. This would provide vertical support, but put the frame in tension not the normal compression. I would need self tapping pan head screws long enough to go through the frame and at least 15mm further (5mm gap + 10mm into lintel). Probably means a 70mm screw which difficult to get so may end up as "woodscrews". Imagining that a approx. 75mm high galvanised L bracket exists that I can put a few in. The vertical part would screw to the fat part of the cavity closer and the horizontal part would screw to the top of the bricks. Google waits. I don't think it's an option to just support the bottom in the corners as the window will then sag in the middle. Longest window I have to solve this for is about 2.5m wide.

Fitting windows now. The tile cill is to go in after (recommended by Brockie) Wondering what is going to support the window at the bottom though as the cavity closer is only supported by the inner leaf. Packers between the frame and cavity closer would be normal I guess but the cavity closer isn't fully supported.

Sorry forgot that. So that leaves a pocket 12mm by about 40mm around the window. Are you sealing that off with anything or leaving it open to the outside?

Most people use low expansion spray foam I think, but I'm going to try an expanding foam tape. As you say the airtightness is then done separately. Thanks. Did you take your tape yo flush with the front face of the window or still recessed behind? The second being either filling a groove or overflowing behind. If not groove, I guess its a matter of how close did you get to the front face of the frame?

That's not so encouraging ? The Iso Chemie Bloco 600 is '10 year performance guarantee*'

I also see that Iso Chemie make Bloco 600 which appears Similar.

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: