Thorfun

call me cynical (and I am) once the PIR is factory fitted and covered by a VCL membrane, also factory fitted, how do you know that they've done a good job in the factory? you're just assuming that the factory workers give a **** and do a bang up job. but I wonder what the reality is? this is what we did. it wasn't hard work but it is time consuming and not completely pleasant! the roof was a real pain though. but I know that the mineral wool is well fitted and that every join of PIR is foamed. if I had the choice again I would seriously consider a twin stud/I-joist wall filled with blown cellulose for performance and speed of fit.

not sure I'm qualified to answer your questions about your thought process. EWI is possible but you need to be sure that you have a condensation analysis done (as you should for IWI though!). There are quite a few on here that have done it so maybe one of those will be along to assist. might be worth doing a search or trawling the insulation subforum

also, there's a lot of discussion about decrement delay of insulation and it's effect. PIR has poor decrement delay and also poor sound attenuation when compared to mineral wool. what size timbers is your TF being made of? I presume they're bigger than 120mm so you could fit mineral wool between the studs and then insulate internally/externally with extra PIR to get better U-values but also get the benefit of sound attenuation and decrement delay of the mineral wool. just a thought and sorry to throw the spanner in the works when you're so far down the line!

it makes the building bigger so planning might have an issue, assuming they ever come and check I guess.

our plant room is in the basement but is pretty much central to the house so it wouldn't be a huge increase in pipe length to put it there rather than in the cupboard that is on the ground floor directly above the plant room. I might ask our plumber to cost up the manifold and extra pipe and see how much extra it would be.

I loved the idea of a manifold system even one where each room can be isolated from the plant room. but when our plumber came to price up the job and I mentioned it he said it'd cost a lot more and we'd need 24 pipes from the plant room instead of 3. we will have 4 bathrooms, 2 x WC, kitchen and utility room so with each having a cold, hot and HRC it just seemed excessive amount of pipework for a convenience that I don't know when/if we'd ever need (isolating a room that is).

speaking from experience...make sure you don't spend money on the self-build until you've exchanged contracts on whatever plot you find. we thought a property purchase was going through and so we paid an architect to design a new house, paid for topography reports etc only to be gazumped 2 weeks before exchange. so that was a substantial amount of money down the drain. we learnt that lesson the hard way. for this the day after we exchanged contracts I phoned up architects to get them round to view the plot safe in the knowledge that any money I spent I could sue the sellers for if they didn't complete after exchanging contracts.

it's either twice as much or takes twice as long. that should be 'rule 1' of self-building.

+1. our 10.5kWp array cost us just over £10k installed with in-roof GSE trays.

Thanks. It’s a GoPro that I already owned.

Ours was multiple pours with water bar strip. they basically built 2 corners diagonally opposite and then struck the formwork and rotated it to do the other 2 corners to make the rectangular box. details here. No leaks so far but it’s only been 6 months.

if I had my time over again I would get an I-Joist/twin-stud (Larsen Truss) with blown in cellulose. I saved a small fortune getting open panel timber frame and fitting the insulation myself but I doubt I'd do it again.

I used a GoPro that I already had. in a waterproof case and powered via POE with a USB-C converter so it's permanently powered up on the roof of our existing property.

30s for me. for an example of what that looks like in a video look at my blog posts.

I had a few spare minutes on this lovely sunny Sunday evening and decided to spend it writing up a blog post for our basement UFH install and screed. We have a 250mm reinforced concrete slab sitting on top of 200mm EPS300 in the basement. The slab wasn’t very flat and so we decided to use a cement based liquid screed to give us a nice level base for our finished flooring. So we put down 25mm of PIR to level things out and also to allow the UFH pipes to be stapled to. I did some quick maths and I figured out that it was cheaper to use the 25mm PIR and UFH pipe staples than to use pipe clips fastened to the slab and a thicker layer of liquid screed and so an order was placed with our BM and it was delivered and fitted by my lovely wife and me. We found this is a pretty easy task to be honest and only found we had to put a small bit of sand blinding to level a couple of dips in one room. In the rest of the basement the PIR just took the bumps of the slab out. We taped the joints and foamed around the edges for a belt and braces approach even though there was a DPM going on top. Next came the DPM layer. We found this a bit of a pain to do! Not hard but trying to smooth it out and keep it square so that a constant amount was taken up the walls was just fiddly. In the end we got the laser level out and set it about 150mm above screed finished level and then used that to ensure we had enough DPM up the walls. Then we had to tape it to the walls but soon found that standard gaffa didn’t stick to the concrete walls nor the dense concrete blocks! We painted the concrete with a PVA mixture and that helped a lot for that but just didn’t work on the concrete blocks at all. Off to Google and this awesome forum and I eventually found Gorilla Tape which sticks well to concrete blocks and we were off and running! Following this we laid the UFH pipes. This was a job we actually really enjoyed. It was very satisfying creating those wonderful spiral shapes. We made some spacers and I was laying the pipe according to the layout designed by Wunda and my wife was walking behind with the stapler ‘kerchunking’ down the staples as we went. At the end it looked so good we were sad to think all our hard work would be covered up and never to be seen again. This was my first time running UFH pipes and also my first manifold fitting and I was very happy with how the manifold turned out. I filled the pipes with water and the pressure gauge showed that there were no leaks. That and the fact there water wasn’t pissing out anywhere! With the liquid screed booked in we needed to get a move on and get everything finished off and ready. The last stretch was to fit the temperature probes, perimeter expansion strip and create the expansion joints for crack mitigation at the doorways. Thanks to advice from this forum’s users I ran the temperature probes in UFH pipe with the end crimped down so as to not allow screed in just in case they need replacing in the future. I got the expansion strip from uHeat on eBay. It came with a plastic skirt and adhesive already attached so it was a real breeze to fit. Not much more to say about that The final thing was crack mitigation strips for between the doorways. After speaking to the screeder I decided to use 5.5mm plywood board. It was an inexpensive and simple solution. I was asked to cut them to size but leave them to the side of the doorways and the screeders would add them as they went around. Obviously I had to put them in place first to ensure I got the sizes right! So here are photos of our basement ready for the liquid screeders. On the day of the screed they turned up early before the screed lorry to setup their pump and check on my prep work. They said it was exemplary and that I wouldn’t believe the state of the prep work of some of the jobs they turned up to! They had absolutely nothing to do to the prep work which made them happy and made me happy that all our hard work was worth it. They put down their little tripod level thingies and waited for the screed to turn up. Once it did it was really quick work and very impressive. If it wasn’t for the fact that they ordered 6.4m3 of screed but the company only sent 6m3 they’d have been done in a few hours but, as it was, they ended up having to wait a good 2 or 3 hours for the last little bit of screed to turn up. They were not happy as, in the end, they had to spend the whole day here when they could’ve been on to the next job. But, at the end of the day we had a wonderfully flat looking basement floor. And 48hrs later we were walking on it. 🙂 All in all very happy with the whole process and I will be getting these guys back in to do our ground floor screed. thanks for reading.

a quick Google tells me that the H05RR-F cables are rubber flexible cables. I see no reason why I need to use rubber cables for my run from the plant room to the external blind. so back to PVC cables then.

the cable hanging down is the one that comes with the blinds. I will run a cable from the plant room to each blind to connect to the blind motor's cable through a hole in the wall behind the silver head of the blind you can see below. the timber cladding (tongue and groove) will come down to cover the slat stack. the cable that comes with the blind motor (a Geiger GJ5606k) has the following written on it:

these will be behind the blinds head unit which will, in turn be behind cladding. so, it will be outside but will not be exposed to UV directly. I'll pop out and take a photo. 🙂

thanks. maybe I can pop in tomorrow and ask why their cable is more expensive than TLC and see what they say! they might price match or offer a better price but if there's no difference in quality between those 2 cables I linked above then why would I go for the CEF product? not sure I really need an account for my electrical goods. I will be buying all our electrical and data cable and sockets but not sure it's worth getting an account when I can get stuff online cheaper. it was mostly for last minute things I've forgotten or need to pop in to town to pick up. maybe I'll just stick with TLC depending on how they answer my questions tomorrow.

I need some 4-core 0.75mm cable for our external electric blinds. we have a CEF and a TLC local to us and I've been on their websites to compare. Can anyone tell me the difference between these 2 cables please? https://www.cef.co.uk/catalogue/products/1959395-3184y-0-75mm-pvc-round-flexible-cable-black-100m-drum https://www.tlc-direct.co.uk/Products/CA0dot75F4B.html the CEF cable is £14.95 more expensive for the 100m drum. why is that? better quality or is there no difference and CEF are just more expensive? And, if so, are CEF more expensive for a reason? i.e. better customer service? no quibble returns? etc. And finally, anyone got any opinions on a CEF vs TLC comparison for other electrical goodies? I don't have an account with either (but am signed up to Screwfix/Plumbfix/ElectricFix who will price match) but I wonder if it's worth getting an account with either CEF or TLC. thanks.

+1 to the comments that state just a sand blinding to level off the troughs. we didn't have many but it's what we did and seems to have worked nicely. as long as the insulation doesn't rock then it's my understanding that you'll be fine.

if you can't hit the 750mm depth then you could consider insulating the pipe. we used this https://www.bes.co.uk/shalloduct-rigiduct-insulation-pipe-blue-4-x-3m-18515/

so we decided to go with Zinc guttering using a dry fix system (it's Zambelli) from Rainclear who did take-off for me and had a massive 30% off with next day delivery! couldn't be happier with them and their service. and I've done the first elevation. laid level without a fall as suggested by @Russell griffiths and confirmed by Rainclear due to the large and deep profile of the zinc guttering. And as @Roundtuit said, it is easy to fit and cut with a hacksaw and tin snips. even managed to fit our outlets without drama. all in all, it is easy and my worries were unfounded. and it looks fab! 🥰

we had electric and water come out at the same time and worked under the same road closure! it was a minor miracle and saved me thousands. some info in this blog post. but we're based in the South East. not sure if that makes a difference though.

house looks fabulous and so does the view! stunning. well done.