MikeGrahamT21

Do the hot water taps do the same thing? Any pressure drop on cold taps?

https://www.buildingmaterials.co.uk/info-hub/insulation/can-cavity-wall-insulation-be-removed Looks like polyurethane can be removed, according to that anyway, may be worth speaking to the experts, call a removal company and see what they say?

Firstly the easy bit, the Kingspan to wall plate junction, yes this can be foamed and obviously ensure the gap above remains clear. and here in lays the problem why PIR cavity insulation gets such a bad rap!! Poor installation. You are correct that will be doing very little work currently, in practice when it was installed and built up, plastic retaining rings should have been installed to keep it held tight against inner leaf. Clearly doing this now would be a major major job. what size cavity is it and what thickness were the boards? How clear is the cavity on the outer leaf side? I’m thinking your probably going to need some sort of wedge, but it’ll be difficult for it to not just dig into the PIR

That’s interesting as I’ve also been getting over voltage errors on my solis ac coupled inverter for the last 6months or so, have checked at the time of the alert and the voltage is just fine, even the Solis says it’s normal range. id advise to raise a support ticket with them, they’re really good with this type stuff

I don’t see how digging out like you have would cause leaks in your concrete floor? If anything any water would come out and pool in the bottom of the trench. I did the same dig out when installing external wall insulation and didn’t have any issues. what makes you think this has caused it?

If your going to that extent with vertical cut outs too, you may as well just take it all off and wet plaster the whole wall, plus that way you’ll get guaranteed results

it’s a good plan if you don’t mind the mess and the replastering works. I wouldn’t bother with foam for this method though, how about buying a bag of plasterboard adhesive and take the section out, apply adhesive and stick some new board in, ready to be skimmed? Another option is bonding coat plaster and then skim on the small section I wouldn’t get too excited about a fix even by doing this, you will likely improve it but it won’t be perfect and will still leak air. I’ve done loads of work on my only room like this and still keep finding air coming through, but it is better than it was

I too got the thermal camera out on my verticals and could clearly see the diverter. In my case it was half and half, diverter was clearly visible in the centre of the bottom horizontal

Yeah it’s something which would need to be done before boarding out, and if your going to the effort of taking the boards off, for me I’d just wet plaster, but I would imagine it’s just not financially viable. I too have one room with dot and dab from when I didn’t know any different, I’ve tried my best to improve it but it’s still far from airtight, again not much I can do now without a lot of time and effort

Just tiles, looking at the overhang of roof you may need 3 rows off to see the internal junction but it will give a good opportunity to see everything and fix what you find. Quite likely, you can have really snug fitting PIR and you’ll still get air leakage through it. with the tiles off you may be able to improve the issues. The problem with dot and dab even when installed as per manufacturer guidelines with continuous bead of adhesive, it only takes a bit of block shrinkage to create a new path for air leakage, lots of people use a parge coat on the blocks to get around this but for me wet plastering is the easiest way of achieving airtightness which you can clearly see long term is staying that way.

It’s surprising just how little of a gap you need for a huge amount of airflow to come from behind plasterboard. definitely investigate everything you can, that should be fairly easy to access without having to damage anything

Chances are you’ve got a plasterboard tent then especially with how much air flow you are getting through your sockets. it’s very hard to resolve this once it’s been fitted, you can try injecting flexible foam behind all around the perimeter at 100mm intervals, but it’s not easy to get a perfect seal. either wet plastering the walls or having a properly airtight service void is the only true way of resolving this, but it would mean removing all of the wall boards and starting again.

Dot and dab plasterboards on wall by any chance?

The tiles under the flashing at the bottom of the window haven’t been prepared properly by looks of it, you are supposed to chamfer them to reduce the amount they stick up to increase water run off, this is done at a horizontal plane… hope that makes sense? from a non install perspective, give everything a good clean, and consider replacing the seals

Rather than totally diverting the flow entirely through another radiator, would it be instead feasible to use 2x reducing tees on the main flow pipe out of the boiler, keeping the 22mm straight through, with 2x 15mm pipes going to and from an additional radiator? I've had a look at heating pipe designs, and think this small section would fall into a 1 pipe heating system with bypass, with the remainder being a 2 pipe? Would it just mean a slightly prolonged heating period for the additional radiator on the 1 pipe? Alternative to keep a two pipe would be a total diversion through the radiator before manifold, but then going through a 1/2 valve (which would be permenantly open) would this lead to too much pressure loss? I'm thinking using the 1 pipe with bypass may be an ideal neat solution for a little extra heat in the one room which is struggling?

There are products designed exactly for this, though quite expensive https://gapogroup.com or you can opt for what most do on here, as I have done, get it as tight as you can and inject some flexible expanding foam around the perimeter and joins, which will move with any shrinkage. it’s hard to say just how much PIR will shrink over time, seen some photos of crazy shrinkage, I’ve installed quite a bit in my place over the years, closed stuff off and gone back to do other work and it looked the same as it did when I put it in, 10 years down the line. It’s possible that there have been many bad batches

+1 for ATAG, mine has been flawless since install

It’ll be a variable vapour control layer, during the warmer months it allows moisture to pass but not during the colder months

Wow, yeah just a slight gap! lol Had a look other day with the Thermal Image camera, and could see a point on the bottom bar around half way where the temperature differed on each side, so I'm guessing there must be a flow restrictor in there. The big ones of these are 8 bars wide, the first 4 bars were slightly hotter than the second 4 bars, which married up with the point where it seems there is a flow restrictor, so it seems in my case this may not be the issue, and the whole of the rad generally showed quite evenly hot. If they ever come off for any reason, i'll be sure to check this, very useful thank you

Its certainly been cold this past month, especially for the amount of water involved in plastering. I feel any mould and the smell has come through rather quickly, even given that scenario. Are there are plug sockets/switches on this stretch of wall that you could maybe remove, and have a chance of some additional investigation, whether that be with a camera or just your sniffing gear? https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/1019707/iwi-guidance.pdf This may help answer some questions, one example which may be appropriate: You may have inadvertently left a small air gap between your insulation and the old plasterboard, giving a space for condensation to collect. Was the original wall completely flat? I've been through a few guides for retrofitting and none specify that you have to remove any plasterboard before application, its not recommended however, the emphasis is on ensuring no gaps are present. How about getting in touch with British Gypsum, or Kingspan and ask for a potential solution for IWI, with existing plasterboard and see what they specify? Examples of differing opinions: https://www.kingspan.com/gb/en/knowledge-articles/can-you-fix-insulated-plasterboard-to-existing-plastered-walls/ (though this is from 2022 and guidance has since changed) https://insulationgo.co.uk/blog/insulated-plasterboard-over-existing-plasterboard

First off, you can continue with carpets and doors as you've suggested, this is normal practice for MVHR ventilated homes. What sort of temperatures are your bathrooms at currently? My bathroom tends to sit around 22C and any condensation clears really quickly, its quite a large space so have 2 extract vents in different locations with 1x 75mm flexible pipe into each. The soft gentle airflow from the vents is how its supposed to be, its an incredibly low throughput system that does its job by doing both the push and pull of the air on its own, rather than traditional extract which creates low pressure which has to be balanced from air leaks. I would not expect an MVHR to be whistling under the doors, that in itself would be wrong. Please take some photos of your MVHR install so we can spot any errors!

Have also just discovered that the flow diverters aren't always included as standard, will attempt to use the thermal camera to see if i can see any signs of one in them. The radiators do get evenly hot, but take some time to heat all of the bars, maybe this is part of the issue?

Went through this spreadsheet, as i'd got some incorrect values in there, and also changed the room temperatures to what i like them at Any further thoughts on my original idea as to whether it would be feasible to do this with the flow circuit to manifold?

Absolutely, it’s partly for their benefit. Ask for a full quote showing how much for each component of the works, that can sometimes beat them into submission when they have to prove what the money is going towards

Target temp is 18.7C which I find more than warm enough, today is another miserable day but milder, and already above this target. Overnight i've had it set to Off for some years now, which works in most cases, its just the cold cold days where it struggles a bit. This year, from 1st to 28th (so far), this room has consumed 347.51 kWh in gas according to the Tado calculation. I'll have a mess with overnight temps rather than it being off completely, and see how it compares. There are 4 controlled zones, Dining room (this one which also includes snug and kitchen), Bedroom 1, Living Room and Garden Room (includes Bedroom 2). Other zones are Utility and Bathroom which just act as bypass radiators taking whatever heat they can whilst the system is on. I hadn't heard they were poor, they were amongst the highest in heat output when i was looking at new rads for a given size. Wouldn't be able to swap for anything else really as don't want to mess with flooring and break airtightness, so restricted with width. There is the possibility of getting a triple version of the vertical, currently have double. This was the calculation I did a while ago, but the flow temperature has been reduced 10C compared to 55C which i was originally aiming for. Having lived in it, i don't think it needs a huge amount more output, which is why I was wondering if a small radiator branched off of the flow run would work, and not compromise flow to the rest of the system? And this is more future planning than anything else.