Steve450

Hey, good to here from a fellow 70’s renovator, I have stripped the house now back to the timber floor and walls, I have 70mm extratherm PIR to go in between studs this week, then foil membrane over the top followed by a 1 inch cavity service void, once the electrical work has been done I will send some photos. Not sure if I’m going with plasterboard or soundbloc but the 70mm PIR will be better than the 50mm fibreglass, Good to hear what you have been up to…was the under heating (overflow heating good to install, where did you buy it? Did you need to PIR between floor joists? I’m not settled on floors yet and I have options to either buy 13 radiators and insulate floors the best I can or buy a water system for joists, I’m not sure what to do many thanks for any info Steve

Hi thanks for the warm welcome and thank you for your reply and time to work out the calcs. Impressed! I can take some photos in the morning and upload them, now that I have Googled it it does seem like fiber glass batts in the brown bags, on concern is they don’t feel 70mm deep but if I strip all the plasterboard I guess I can inspect closer. I’m guessing the original plasterboard covered in wood chip wallpaper can’t stay on and PIR over?

I have already purchased the 70mm PIR but if someone could advise a good spec I’m sure the merchants would exchange it

Thanks for your reply, yeah I’m hoping for some more views and advice, I was shocked when I cut inspection holes to find the 70mm stud. I’m guessing I wouldn’t be able to extend up with it but I’m no where near that point l, I have no kids and a big bungalow to try and insulate lol I just want to get it the best I can without losing too much floor space. The 70mm studs currently have material insulation in a brown paper bag which I’d guess is no great than 50mm and it’s extremely breezy when I poke my hand in the void, maybe I could strip the plasterboard and old wool then buy new wool then PIR, maybe should have planned it out better

Hope that wasn’t too confusing, basically to add to my single 70mm PIR external insulation between studs, do I add the 30mm PIR over the 70mm then can I batten over the 30mm with long screw for a service void and then plasterboard? or do I batten then add insulated plasterboard?

Hi all, I have a single brick external leaf rendered with a 50mm cavity then a timber kit with paper, ply wood and 70mm studs. I have jumped the gun a bit and purchased 70mm PIR. My plan was to fit tightly inside the 70mm studs then fc foil vcl then battern 2x1 for a service void then plasterboard or soundbloc, I’m aware that would only give me roughly .28 U value going on the average figures I’ve got back from online calculators. my question is, if I was to add another sheet of PIR say 30mm would I install it directly over the stud face and 70mm PIR then install battens and plasterboard or am I better installing the battens over the 70mm PIR then installing a 30mm PIR or 40mm insulated plasterboard and if so on either option to gain a better U value of approx .22 where would the VCL go? thanks in advance

Thanks

Hi everyone, I am completely renovating my 70’s bungalow. I would love to hear your ideas on is, what insulation spec would you do with my current build up on the external leaf, I am replacing all windows, doors, heating and electrics so I want to get the insulation within a good standard, currently the kit has 70mm stud walls filled with what looks like 50/60mm cotton insulation in brown paper bags with a clear polythene wrap stapled over finished with plasterboard nailed on, studs are 600 centres. I’m guessing the U value is way above .4 with only basic insulation. my thoughts are option 1 - do I leave the walls as they are, they are covered with chipboard wallpaper, I can strap on top of the old plasterboard with say 2x2 into original studs, then add 30/40mm PIR and have a void for airflow and cables. I would lose 65mm off each external wall, I’m guessing the U value would be down to .3 ish with this set up but could there be a chance for condensation? Option 2 - rip off old plasterboard, fill the 70mm void with 70mm PIR, wrap over with foil avcl, stitch a 2x1 batten on top of old studs and have a service void of 25mm, I would only lose 25mm off each external wall Outcome - Would option 2 with 70mm PIR be more insulated with a 25mm service void and one sheet of plasterboard than option 1 with original 50mm old wool, plasterboard, 40mm PIR and 15mm service void and plasterboard? I also have the option with option 2 to batten with 2x1.5 battens or 2x2 which would take my 70mm cavity to 108mm or 120mm which would allow a PIR of 80 to 100mm and still have space for a service void to run my cables. I think cost wise the only difference is buying the thicker PIR, I need to buy the plasterboard regardless but option 1 saves a lot of time stripping and getting rid of old plasterboard and insulation and skips etc. I could also just sheet over the plasterboard without doing anything so it’s the original build up but double sheeted, would help noise but not so much insulating the property, this would be cheapest and quickest but I am after a quality set up, tell me what you would do! And is PIR worth it, only looking at it as it saves spaces over rock wool. If you have got this far thanks you for reading steven

Hello everyone, i hope you are all well and set for Xmas. i have bought a timber kit bungalow that was built in 1970’s by a lady I knew so I decided to buy the house and renovate it and bring it back to life. I am knowledgeable and handy in many trades but need some help with technical queries so I am here to gain expert advice from professionals and gain insights into other peoples perspectives and ideas. The main questions I have and I will post these questions in the relevant forums also is about my timber kit structure and insulating it. Added by mods - the link to Steven's question is here: [Same question deleted by mods] steven