connick159

Thanks for the drawing, unfortunately i did not do the ones between the rafters like that. I left them square at the ends and sat them on the wall plate. They are now all fitted, except between two rafters. They were held in pace temporarily and then used the illbruk foam around perimeters to hold them in place. Was then going to comeback over them with the next layer and screw them in with drywall crews and washers. I do have 170mm wool insulation closing the cavity but undoubtedly there are now gaps in between wall plat and in rafter PIR. I dont have internal wall insulation but other than that the drawing is what i'm doing. thanks.

thanks!

Hi, tried searching but not sure of the terms so coming up blank. I've just installed PIR 100m between rafters on a pitched roof. Now about to fix 50mm PIR under the rafters and have a question about what do do to the PIR boards where they will be butting up against the wall plates. Do I need to cut them at an angle so they lay flush with the wall. Alternate is to leave as is but then assuming I'd have to fill the gap which is left at the wall with other wedges of insulation or possibly spray in foam. Can anyone give pointers or even detail pics of the recommended way to do this please? thanks in advance.

Thanks for the updates, what company did you use for the beads?

Hi, walls are all done, roof on, windows all fitted and I've just realised the brickies didn't carry the cavity wall insulation (PIR board) 150mm below the DPC. Stressing out a bit as too late to change it but about to put down floor insulation in prep for UFH and screed. I'll be putting perimeter insulation before the screed but very concerned about cold bridging now. Are there any options for blown insulation into the bottom of the cavity? I still have access in spots where door and window cils not yet installed. Am I worried over nothing or is this a big oversight and will leak heat unless resolved? Thanks.

Thanks Dave, I just found another manual for the PUHZ-W112VAA (example of the unit here - https://www.saturnsales.co.uk/Ecodan-PUHZ-W112VAA-With-Hot-Water-Cylinder.html). Anyway, the manual states the PUHZ-W112VAA is a single fan which sounds promising. (https://www.mitsubishi-les.info/database/servicemanual/files/201803_ATW_DATABOOK.pdf) I had EEC recommend the LG system but based on some other posts, including yours, I'm leaning towards the Ecodan. Given half the property is an older cottage and half is new extension if they do the 11.5kw in a single fan that sounds perfect for us. Cheers Matt

Anyone know if the 11.5kw Ecodan is one of the double fan units rather than single. If it a double then I assume the actual unit is a lot taller with the second fan being above the lower one. We are also looking at this system but need a 300L tank and can't seem to get this combo anywhere. Cheers.

Thanks for all the comments. Appreciate it as always. in terms of running the calcs and seeing if the MCS v Non MCS path is better, how would I go about that without relying on info from the mob attempting to sell me a system?

update: 8 and a bit grand for 9kw LG monobloc system and a 300ltr HW tank. With installation etc and MCS it comes to just over 12k. Not cheap is it this heating caper!

So is this basically saying that all the 'overfloor' types of underfloor heating are no good? (due to heat loss down into slab) https://www.wundatrade.co.uk/product-category/home/overfloor-retro-fit-solutions/reftro-fit-floor-heating-kits/ Cheers

Thanks Andy, makes sense re not the size that counts (perhaps that really is true :)) Appreciate the feedback. We've actually gutted the existing cottage. It is an old stone wall cottage. Walls about 700mm thick with an outer and inner skin of stone and rubble in between. The roof is slate and felt. No insulation now but I'm putting in 100mm or 120mm of PIR boards in the area where ceiling will be vaulted. Other bits with flat ceiling will have 300mm rockwool type insulation bats. All of it is an existing concrete slab with no insulation but I'm adding close to 50mm insulation and then UFH to that section with those over floor UFH board. This entire section in about 55-60 sqm. The new extension is around 60 sqm. Double skin solid concrete block with PIR 70mm in the cavity for insulation. 120mm PIR on top of 150mm concrete slab floor. the UFH and screed around 50mm. only a small part ( 8sqm) will be vaulted ceiling in this bit and again I'll put in 100 or 1220mm insulation. Rest will be flat ceiling at 2.4 again with 300mm rockwool type insulation. Large windows in gable end that face south sw in the extension so will get good solar gain. I know it's tough to ask for numbers on a forum so hoping some links or websites with calcs that folks have use and perhaps recommend. I've tried looking at some of the info mentioned here and spreadsheet but afraid I've never been the sharpest tool in the shed so struggle a bit with keeping up at times with numbers and acromyms etc. We'll get there and it's all a learning curve so just trying to see if any resources available which might help. Thanks again.

Hi all, We just had a ASHP co come out to measure up or extension and original cottage to quote for an ASHP. By the end of it they have we needed around 8.6, then added a 10% buffer which pushed us above the 9kw LG single fan unit they recommend. The 12kw model they recommend is pretty large and a 2 fan system. It is meant to be attached just to side of cottage and I think it is just 2 big visually to fit in there. the extension is around 60sqm and the entire cottage will be 110sqm when complete. I've seen several rather large houses not far from here fitted with a 9kw system by the same company so wondering how such a small cottage, in comparison to some of these large, double story houses, requires such a big system. Can anyone here point me in the direction of some info where I can get myself up to speed with it all please. The ASHP will be supplying UFH and Hot water and the calcs allowed for a 300l water tank. Thanks in advance.

Ok, thanks for that. Makes sense. So it's worth checking back with the supplier of the plan as to why zones are created or split? Assuming that if you could merge split zone in bed 2 for example that this would also then mean you can reduce the size of the manifolds? thanks again.

Can someone please explain why bed 2 has 2 circuits but bed 3 only has a single circuit? I can't work it out? Also, if this was installing UFH in an extension plus the existing property, but in the existing house the UFH was going on top of slab floor already there but in the extension it would be onto slab, with insulation and then screed, would you still recommend a single 12 port manifold or to split them onto to 2 diff manifolds. One for new extension and other for existing house? Cheers.

Hi, I'm wondering if you can use SIP roof system on a non SIP build? At the moment the designer has just drawn it with trusses roof. There are a couple of Valleys and Hips in the roof. Roof to be covered with slate as a requirement from planners. We are currently building an extension to traditional cottage in Wales. Extension is block cavity construction. Pretty standard stuff as that's the "way it's done round here". Any info would be welcomed as I've searched here to see info on the SIP roof system but not found it where it's not an entire SIP build. Cheers

Thanks Peter, This looks more attractive than 12k! Are all the brands decent these days or are there tried and true ones to stick with? Eg. Some of them look like reverse cycle air cons like back in Oz while others are massive things.

Ah ok. Our quote was for a pump plus a water tank plus installation. Stiebel eltron was the brand. 11k still seems pricey. Can't get vat back as an extension not new build.

What 3k!!! We just got a got for 11k. How is that possible?

Thanks, the ufh company near us said the same re the poured liquid screed. Another fella said he only does liquid these days. So much info out there to take in so this forum is a blessing. It's 2 separate UFH areas - new extension will be in screed, old cottage will be overfloor. Although after reading on hear that these overfloor systems are pretty poor and lose a lot.of heat down into floor them i may need to dig up old cottagr floor and go inscreed too.

Not sure of finish yet. Prob an engineered timber.

As title.says, have an extension started and slab 100mm slab already gone down. Plans are for 100mm PIR and then 50 mm screed. Have we blown it for UFH by only allowing for 100mm insulation?

Thanks John.

Looking for some info about how best to tie in a new blockwork extension into existing stone cottage. Is it just a matter of using the regular wall starter kits (furfix) or is there specialist products for use in stone walled buildings? Thanks

Thanks Joe.

Thanks Joe, sounds like a good way to insulate the pipes. Where does the manifold have to sit? Is it by the tanks on the inside of house? Not to sure how far the run from the ASHP to the tank will be yet as still unsure of location for both pump and tanks. Cheers