EinTopaz

Currently open to cold side. From bottom to top ours goes Pasterboard 50mm kingspan 100mm kingspan (between rafters) 70mm airgap membrane battens tiles

All fair point and true enough. I won't be doing the roofing myself. But i'll be up there with the team, insulating the gaps as I find them. As we're totally de-roofing it sort of felt silly not to add more kingspan while im there. I know it wont be night and day difference. But for £500 and a couple days of my time. Why not eh. RE: wall gaps. Absolutely, take a look at this video. We've a vented tile on the roof for an extractor fan in the bathroom that I wanted to inspect. Looking under there confirmed that I need to have all the tiles took off and insulate all these roof properly tbh. it's a complete mess. Incidentally, after i've got this sorted, im going to name and shame the company and directors. As they've since refused to rectify. vented_tile_beneath.mp4

Yes going to be completely stripped tiles off, battens and membrane all off. Do you think 20mm airgap between kingspan and membrane will suffice? 50mm insulation is no more expensive than 40mm weirdly. And probably easier to sell on if I over order!

Yeah ok, if I add 40mm more kingspan that'd leave me with 30mm clearance to top of rafters. I read the 50mm clearance required is because of sagging of the membrane etc. But ours looks pretty tight to be honest.

thanks, which figure on that link describes my setup the best? We've 50mm beneath rafters, 100mm inbetween rafters, then membrane, then battens, then tiles I'm looking to up the bit between rafters to probably 160mm edit: our soffits are vented. Forgot to mention.

Changing topic ever so slightly as I need an answer on this for the roof. As I'm about to order all the extra Kingspan for it (i'll be removing all the tiles and taping/sealing all the gaps between insulation of what's there already AND adding more whilst im there. My question is how much of an airgap do i need to retain between the top of the Kingspan that's between the rafters AND the underside of the vapor proof membrane? In the photos below i've shown how my tiles are arranged, they're sat ontop of 25mm counter battens so a good 25-40mm or so higher than the membrane. The rafters are 170mm tall, there's 100mm Kingspan between them. Given that there is an airgap between the membrane and tiles. How much of an airgap do i need to leave between top of kingspan and underside of membrane? 1" or 2"? Or can I entirely fill the void between rafters with no airgap at all?

Looks great, i think i'll need a proffesional to do this for me by the looks of it though. Do you know of anyone in the north west of England?

Is there a minimum cavity size needed though? This was the issue I ran into with EPS beads, the company insisted on minimum cavity 40mm consistently to avoid issues with damp.

I did, couldn't find anyone who could reasonably remove PIR. Can remove beads or even Wool roll but not PIR, so far. My issue with removal is, I dont even know if the replacement would be as good a U-value. If its beads for example. So id rather repair what's there and add more stuff over the top, ideally. Simply for the fact that its more insulation after all the cost and time.

From the building WIP photos everything looks really flush to that inner block so i'm actually not sure how it could've broke away like this. Its got me questionning whether my cavity really is 150mm total. That is what the builders told me, but then i'm wondering why they've only used a 90mm interlocking PIR, as I can see the receipt for that material specifically. Why not have a smaller cavity and save on the footings if its not going to be filled? Or why not go thicker PIR. I'm going to dig on this a little.

Will do, to be honest it was simply a recommendation of some local businesses for me to enlist the help of,

With it being PIR interlocking stuff, I imagine that's going to be a complete nightmare. May as well remove the bricks at that point

Im still not sure how to apply the foam, looking for a company to do this. Don't fancy ballsing it up myself.

Was starting to consider that myself yeah. Not a bad shout. Will see if it's possible.

I did yeah, pretty early on, we noticed air coming through wall light fittings etc. Those are all fixed now. I know what the problem is, it's poorly installed wall / ceiling PIR board, which im trying to resolve.

Thanks for the heads up, i've just messaged you directly. I wasn't fully following the bit you meant by the air ingress. But can carry that on in the message.

It's not a bad suggestion but no i dont think so. As we've got cavity closers over the windows etc. It's going to be hard to consistently get the stuff pushed back to the wall. I don't think I have the energy or the heart to have all the bricks removed and have this all re-seated properly. So i'm guessing my only option now is external wall insulation. Anyone know a company in the North West that they'd recommend?

Update on this one, as i'm still battling away trying to improve it where possible. I had a survey done today by a local wall insulation company. I was looking to have the EPS beads put into the walls, specifically in the air gap between the (poorly installed) kingspan and outer brickwork, as I figured that'd probably be the easiest way of dealing with the problem. Unfortunately the news I got was not what i'd hoped. The suveyor said they'd need a 40mm cavity consistently to work with and when they put the camera in ours, they said it was mostly 20mm and in some places, no gap at all, I guess meaning that the kingspan has come away from the block as much as 50mm in some cases. The surveyor said they can't proceed with the EPS beads in this case. Just wondering if anyone on here has come across this and know what options i still have open to me? External wall insulation looks a no go as i still have an airgap between brick and kingspan. So really at a bit of odds on what I can do now. Help!

No issue with the designer rads in and of themselves, as far as I can see.

will that work with a system boiler where the expansion is internal?

Yep this was my first plan of attack funnily enough, as i suspected it perhaps wasn't getting the heat away from the boiler quickly enough. Ive been running it at 6 for the past few weeks, no discernable difference really. There is another pump mode you can put the pump in where it's speed is relative to the burner output. In the manual that reads as if the max in that mode is far higher than 400mbar....but when I tried that mode i got some very bizarre results, even worse than constant pressure.

thanks, the graph i posted above does allude to the fact it might be fine if I run a really low charge pressure. But based on the fact that I guess there's no such thing as too much expansion capacity. I may as well just add another 18L rather than fiddling about with the internals of the boiler.

Return temp i've got no idea, it doesn't let you see that on the LCD display.I need to monitor it myself with one of those fish tank thermometer things. On the flow temp, it does one of two things. Either hits target temp, of 73' or so, then goes entirely off (burner goes off) for maybe 30-60seconds? during that time the flow temp drops by about 25-30 degrees. Then modulates down to a lower % and gradually creeps back up to 73' then stays there stably. Sometimes it just gets to temp and modulates down incrementally. But either way its showing a higher number there than what i'm "feeling" on the rads for the first hour. Though interestingly when i whack it into "chimney sweep mode" everything gets dead hot.

Yeah nice, thankyou for this. I will put the thermal cam on this weekend and see what's going on. The designer radiators are called "Milano Windsor" from Bestheating.com I called their "technical support team" and asked about whether they have a diverter already in etc, they said they're required because these rads are specifically designed for water to go not simply pass through the bottom. So sounds like they have an internal baffle of some sort already, they also said it doesn't matter which way they're fitted, front to back, upside down. They said the design is symmetrical in box axis.... That said I've not put the thermal cam on yet. Appreciate your point about heating temp, it is a large property, hence why we put this second boiler on the ground floor solely to do rads. Tbh most rooms do get nicely to temp, just the inconsistency of which rads get hot and the boiler modulating down prematurely are the two things giving me a headache. The rad without the TRV is actually a towel radiator. Like the one below. Which do I adjust to essentially dial the bypassing down?

As far as I know there's no ABV. I cannot see one externally anyway. There is solely one radiator in the circuit (towel rad in bathroom) that has no TRV Running 73 degrees because thats how hot i like the radiators. It does modulate down to 44% eventually after maybe an hour or so. and I can see fluid coming out of the condense pipe. So it is condensing. return temp, not sure. i'll list the rads out properly in a future post. good shout. also good shout on the vertical rads, i do have a FLIR camera so i'll take a look. Out of interest should they or should they not have diverters in there? the place i bought them off told me the TRV should be diagonally opposite the bleed valve because of something. I imagine that's related to what you're saying?