Mr Blobby

Our original design was to put the insulation on top and have a warm roof but it proved problematic. I forget the detials but I think the SE didnt like it. Something to do with screw length to fix PIR and sarking.

We have a similar roof construction to your design. Cold roof, warm loft, standing seam on top. It works well giving us a warm space in the loft and plenty of space for the MVHR in a warm space, but is not the cheapest option. As others have said, use wool between the rafters and PIR under. No way you will cut the PIR to fit snugly. Fix and tape membrane under the PIR with battens. If you want to plasterbard then fix the plasterboard to the battens, thus keeping the membrane intact. We attached our cieling joists to a timber fastened to the wall under the joists so that we could run the airtight membrane behind it without being penetrated by joists. Like this: Frget about GSE inset panels on a standing seam roof. Use S5 clamps instread. And Standing seam is too nice for panels so install them at the back only. You will understand as soon as the roof is on. I'm assuming you have a timber on top of a steel ridge beam. Its not clear from your drawings. You need to keep the steel on the warm side, not in the middle of the insulation. Assuming you have gable ends then build the inner leaf lower than the outer so that you can pack some insulation between the top of the wall and the timber directly under the standing seam. We used sarking instead of ply or osb. More time and cost but the roofers loved it. In retrospect I would have rn the airtight membrane vertically instead of horizaontally. I think it would have been easier to install crease free. And better if the roofers had cut battens to install the membrane in sections but, for whtever reason, my roofers hate cutting battens.

Thanks for the advice. I visited the other house my builder was working on about a month ago when the renderer was on site. He had a sprayer and a couple of helpers feeding the mixer, so to a layperson like myself, it looked like they knew what they were doing. Final numbers from the renderer are just in: Parex BL10 white: £12,200. Which I did not ask for (I asked for krend silicone K quote) because AFAICS the BL10 is not silicone based and crack resistance is important. Parex acrylic: £24,000. I'll look again at the KRend reference house down the road, and probably end up with that as the safe and cheaper option.

A whole year has past, sto rend has gone bust and we still haven't had the house rendered. After talking to the builder's regular renderer we have a choice of either a 2-coat solution of Parex acrylic with a very thin coat on top, or a single coat of KRend silicone based render. Render guy says the acrylic is the best product in terms of colour and robustness, but he would say that, as it's twice the cost. KRend is about £35 sq/m, acrylic 75 ish. Do those numbers seem reasonable? Builder thinks I'm bonkers to spend more than Krend. All his other builds are rendered with Krend silicone and he seems to think the KRend great. Our house is block build. With external area of abour 300 m2 then its about 10k more for the acrylic. Is the renderer correct, is the acrylic a better product, is there anything I should look out for?

Your pic above is very neat. Two of these (intake and exhaust) in each room would be great as an alternative to a pelmet, but how did you connect this grill(s) to the plenum? Do you have any pics of the ducting in the loft? Did you buy all the ducting and grills from ductstore.co.uk?

I think that's actually the right way up, the intake sucks air in at the bottom and spits it out the front. Not much, but hopefully better than just slab cooling, esp in bedrooms with solar gain and carpets on the floor. And we are in Northern Ireland where it rarely gets above 23C on a summers day. I'm getting the impression that pelmet is the way to go here 🤪

Yes, warm airtight loft. Plenty of room to install a pair of these in the eaves, one over each SW facing bedroom that are most likely to overheat. I think taking the intake air from the loft will be ok, as it would mean only one grill in the ceiling, and easy access to change filters. The supplier tells me the FCU in the above image can only be installed horizontally because of condensate tray (although I would be running above dew point). I don't really want to build a bulkhead like a premier inn bedroom. I would prefer a single exhaust grill in the ceiling facing downwards. This would leave the FCU higher in the loft which would also make for an easy connection from FCU condensate drain to the pipe connected to the condensate drain in the MVHR, leaving the option to run below dew point, should I ever wish to do so. This is a good point, the air in the loft being potentially warmer than the target bedroom. This is not really to cool the whole house as we have cooling in the slabs and some external blind and solar glazing. But I am concerned about two SW bedrooms that may be at risk of solar gain overheating. Maybe building a bulkhead is easiest. Otherwise the challenge is connecting ducting from hotizontal FCU in loft to a single grill in the ceiling. It would be a 90 degree angle and about less than 1 metre length. Has anyone done this or similar?

Has anyone on here actually installed an FCU like this (or similar unit) in the loft, for cooling, connected to an ASHP and with the exhaust grill in the ceiling? If so then please tell me more about the install and what is needed. How is the FCU ducted to the exhaust vent? Did you install it vertically? Did you use ducting from the FCU to the grill in the ceiling? Some pictures would be lovely.

One more thing to consider is the width between seams. Standard is 600, but we chose to have 400 centres. Looks better and possibly less canning with 400 centres because we have only one panel with signs of canning. More expensive of course, but not a massive difference.

We have prefa aluminium, which is ok, but the ridge detail could have been better, something I didn't think about at the time. Confirm the details like this before install. Roof buildup is also important. There are standard guidelines for metal roofing with vented timber under the standing seam. We used sarking board instead of ply, and I think it's better for not much extra cost.

I like the German kitchens. Another German brand, brigitte, is the cheapest I think. That's what we are getting. German kickboards are smaller, which look a bit nicer. That's probably the main difference 🫤

Is your pump that runs 247 external to the heat pump? Or inside the HP? I think Panasonic has an internal pump and (I assume from being unable to see anything in the user manual) that this water pump only runs when there is a call for heat. Running the pump all the time to distribute heat makes a lot of sense. Add an additional water pump to do this?

Do you do this with a pump on the manifold, or with the pump in the heatpump? If the latter, then is this a common feature of heatpumps, that the HP pump runs, or can be set to run all the time, even when the thermostat temperature set point is reached? If the thermostat set point is reached and there is no call for heat, then the pump still runs and pumps water round the loops?

It looks like Sto Limited, the UK and Ireland distributors for Sto rend, and owned and controlled by Sto Germany, have gone bust. Which is not good. I tried to contact their support people today but have been informed that Sto Ltd is no longer answering support questions and the insolvency practitioners have installed new managers. Sounds like its not a happy arrangement 😕 and the workers have downed tools. It looks like other Sto resellers all go through Sto Ltd, so this is likely going to impact supply and support. Does anyone have any further info on this? Is this the end for Sto, or just the UK operation? If not Sto, then what other product should I use? KRend or Weber?

The problem is the windows are actually in place so cutting the outer leaf risks damaging the windows. I reckon I could cut a hole carefully with a grinder but perhaps the builder knows the bricklayer won't have my patience and will hack it with a stihl saw without much care for my windows. Also the windows are on first floor with rubber roofed porch underneath so more scope for damage from falling masonry. (I know, its a crap place to end up in but I can't turn the clock back😕) I'm also told that if we did insert a lintel and a course of block then the render would still be at risk of cracking anyway because its new block against old block (although I'm pretty sure this would be more stable than a timber stud bolted into the hole). Thank you @nod for your sage advice. So for a silicone based breathable waterproof render like sto, we should cover the front and underside of the timber stud with render board. Then do block wall render buildup as below, with reinforcement mesh across the join from timber to blockwork. Should I do anything else with the timber stud, like bitumin paint, or wrap in breather membrane? Would I need to leave a ventilation gap underneath like a timber frame build?