jayc89

Glad you're getting sorted. A builder we've been speaking with also mentioned Liniar. They have a "Resurgence" range which would also suit our property pretty well. With triple glazing they come in at around 0.9 and are, apparently, comparable in price to the Alitherm frames (still waiting on price though). We're not going for a certified Enerphit refurb, but even so they sound promising! https://www.liniar.co.uk/upvc-windows/resurgence/

How did you get on with the Alitherm frames? Do you know which model, specifically, you've purchased? A local window supplier has been recommended to us and they also use them.

Cheapest I've seen online is at https://www.fastbuildsupplies.co.uk

I desperately want to use MF for some stud walls that I'm going to be building soon, but from what I've seen online, it's coming out ~ 50% more expensive than using timber. Am I looking in the wrong places? Who's generally the cheapest for MF parts?

I'm putting up a stud wall. Total span is approx 4m inc a new door frame. Where I want to put it is over a 60mm concrete screed with UFH loops in it, so I can't easily screw down the sole plate without risking going into one of the loops. What's the best alternative solution? Glue the sole plate down, plenty of mechanical fixings to the head plate and noggins?

That was my original intention, prior to considering spray foam. It seems there is no silver bullet out there, unfortunately.

Wouldn't that ultimately render all floor slabs that are insulated using PIR useless over time? Surely there would be reports of slabs installed 10, 15 years ago now having problems?

Isn't Icynene open-cell whereas Isothane is closed-cell? I assume the former would also provide a higher U-value, like for like.

I have a similar set up. My plan is to install weather compensation on the boiler so the flow temp adjusts based on the outside temp and have my UFH mixer valve set to the highest the floor can accommodate (around 45c). So in the coldest depths of winter, the boiler will ramp up, but when you just need to take the chill off it will be running at a much lower temp. You mentioned you're running an older boiler, so this might not be an option for you. Does the boiler also heat your hot water? If so, does that have a different temp setting? This might limit your options too.

Was it blown in as a secondary thought? If you shift it out of the way, can you see down the cavity (i.e. is it not closed)?

I've had eBay alerts set up for cheap MVHR and ASHP units for a couple of months now. Sods law as soon as I'm ready to purchase something, there are none available.

Thanks @nod do you still double stud in the corner, where the board should be pushed up to, so the first stud on the perpendicular wall has enough to grab on to when it's fastened over it?

Glad this topic is in the Plumbing section.

I'm framing out our house in prep for internal wall insulation. I'm deciding between timber and meta framing. Timber is looking more expensive, so I'm leaning towards metal framing. One unknown I have with metal framing is what the corner detail looks like to accept plaster board on both faces. Is this the correct detail? Does the 2nd C-Stud on the rear track need to be wider to accept both the PB and a screw through form the adjoining C-Stud? Separately, for the stud that runs parallel to the ceiling joists, how should the track be secured? Noggins?

I'm fairly sure I've read users on here, in new builds built to PassivHaus standards, or near to it, are also running a single stat. I could be wrong?

I really don't get the need for so many stats. We started off with 3 downstairs and I've recently reverted back to a single stat. The entire ground floor now heats up pretty evenly and over the last few days our upstairs radiators haven't come on at all. This is all in a 1850's house that currently leaks air like a sieve.

Best quote so far for closed-cell spray foam is £20/m2 at 75mm depth. Given 75mm PIR boards are around £42 each and cover 2.88 m2, they work out at £15/m2. When you add the cost of glue, expanding foam for gaps, tape etc, it doesn't seem crazy expensive to have it spray foamed instead. Am I missing something?

The house work is on a massive go slow at the minute, SWIMBO now has me turning my attention to getting certain rooms ready for xmas! The IWI is on hold until we get new windows fitted, next year now, but I have been pondering how best to tackle it in the mean time. Another thought crossed my mind. I know spray form insulation is frowned upon within the roof space due to associated condensation risks around the timbers. However I don't believe mortgage companies take the same view when applied against walls. Would it be viable to build out a 50mm metal stud wall, approx 25mm from the existing brickwork and have foam sprayed behind and between those studs? It strikes me as a potential solution to both thermal insulation and air tightness as the foam should expend into gaps harder to reach when taping... My understanding is closed-cell foam is pretty similar in u-value to rigid boards and we could, potentially, request open-cell foam around the first floor joists to allow for some vapour permeability, with the understanding that the u-value would be poorer there. (Or just pack these areas with wood fibre (or similar) and protect them when spraying) Are there are downsides to such approach, other than cost (I can't believe how much spray foam insulation costs compared to rigid boards!), I've heard anecdotal evidence of spray foam shrinking/cracking (which would render it useless), but I don't know how old those comments were, is it still a problem with today's materials and methods?

On my quest for cheaper energy bills I noticed a draught coming from under the airing cupboard today. Luckily, the room directly below it is currently back to brick and has a false ceiling (otherwise the downstairs room would be 4m+ tall) so I was able to cut a bit of that away to have a look from underneath instead. I found an old air brick, and what looks to be a 100mm hole in the wall, both are hidden externally by a lean-to roof. So I set to replacing a couple of bricks that had been cut into and temporarily covered the air brick. No more draughts and this evening I'm sweltering! The heating hasn't been on at all and we're still too warm, so I think I can drop the stat down a couple of degrees too. Happy days. Not quite worked out what the air brick was put in for, it's the only air brick we have in the entire house (downstairs floor is solid slab) and there's no signs of historic damp problems in the area...

After tweaking the auto bypass valve, it's now "hissing" when the UFH zone first calls for heat. My assumption is this is whilst the (wax) actuators are opening as the heated water has no where to go. It doesn't "hiss" when the rad zone is on. Should this be expected?

Upstairs rads have been on for the last couple of hours. Over the last hour, the boiler has been cycling every 10-15 minutes, I've gone to check the return at the boiler and it now matches the flow. Upstairs, the majority of rads feel cooler, presumably because the TRV is kicking in, but the stat is still calling for heat. The rooms are certainly warmer than the hallway, where the stat and rad without a TRV is, so I assume that one needs opening up slightly so it's warming up at a similar speed to the rest and therefore the stat is reaching temp sooner and shutting off?

It's a fair point. I'll keep an eye on it. Right now the DWH and upstairs rads are on and the flow temp is significantly lower than it was. Based on comments earlier in the thread. Overshooting the stat was exactly my concern too. I have a couple of those already on the flow/return at the boiler. They're as much use as a chocolate fireguard. The thermometer on the flow is currently reporting 45 and the return 30, the flow is hot to touch, and the boiler states temp is currently 60 which I believe.

Both flow and return pipes on the towel rad were indeed extremely hot.... I've turned them both to off and then opened them up a single turn, I'll continue playing with them until they give out just enough heat to keep the bathroom warm... The auto bypass valve was also fully open (i.e. set to 0.1 bar). I followed the steps above, turned it off then slowly opened it until hot water started to flow through it. I've dropped the boiler flow temp to 60 and increased the UFH temp to 45, so we should be in condensing range for both zones now. I'm a little worried the UFH will now start overshooting the stat and we'll end up with hot spots in the screed, so I'll keep an eye on that over the weekend. Pretty sad, I know, but I'm looking forward to seeing what the smart meter says over the next few days! I'll get a weather comp unit ordered and speak to a plumber about getting it fitted. Thanks again for the fountain of knowledge, y'all! Is there anything else you think I can do right now?

I don't know this is the exact one the plumber fitted, but it looks similar! The rest of the stuff came from a local plumbers merchant so I'm at leats hopeful it's decent kit

Thinking about this some more, @markocosic, I'm pretty sure the valves on the towel rad are already closed a fair bit, as I did this when I balanced the system, so I'm not 100% sure it is acting as a bypass - but I can check when I get back. We do have an auto bypass valve in the airing cupboard which I believe is also there for this purpose (i.e. dump hot water back into the return pipe when the rads are shut off but the stat is still calling for hear) https://www.screwfix.com/p/straight-auto-bypass-valve-22mm/4747V?tc=AA3&ds_kid=92700055281954502&ds_rl=1249404&gclid=CjwKCAjw7p6aBhBiEiwA83fGuu75_NdTru3ij_R-tjBKEXESrck8G5zIn2gQR4wFuKNIttYJWUH1VBoC8PMQAvD_BwE&gclsrc=aw.ds Could this be set up incorrectly? I don't know what pressure it should be set to though... One option I've seen is; 1. With boiler/system cool, set valve to max. 2. Switch heating system/boiler/pump on. 3. Reduce setting until valve is just open (by-pass/valve starts to get hot). 4. Turn adjuster back (anti-clockwise) one revolution (ie. valve closes). 5. Valve will automatically open when system flow reduces. Is that the best way?