November 10, 20205 yr can anyone please confirm the minimum U value for a timber framed external wall and where the info came from . I keep finding different answers im trying to find out what thickness of Celotex or similar I need thanks so much for any help
November 10, 20205 yr Is it a new building or an extension? There are two versions of Part L one for each. https://www.gov.uk/government/publications/conservation-of-fuel-and-power-approved-document-l Edited November 10, 20205 yr by Temp
November 10, 20205 yr 32 minutes ago, Dodgy-diver said: im trying to find out what thickness of Celotex or similar I need If a new build in England allowing for a 15% timber fraction you need 120mm of PIR (U=0.295), ignoring any other fabric layers. There are variations in Scotland and I think in Wales.
November 10, 20205 yr For a new extension wall you need 0.28 W/m2K. For new build house it depends upon the numbers that come out of the SAP assessment, looking at better than 0.25, ideally better than 0.20. After the revelations at the Grenfell Inquiry this week not sure why anyone would consider Celotex or Kingspan.
November 10, 20205 yr 22 minutes ago, ADLIan said: After the revelations at the Grenfell Inquiry this week not sure why anyone would consider Celotex or Kingspan. just briefly read up on this and it doesn't seem that PIR was at fault and I presume your statement comes from the fact that Celotex and Kingspan knew about the issues with the PE and so should be avoided as they obviously have no morales at all.? in that case, other PIR manufacturers are available, right?
November 10, 20205 yr Author 1 hour ago, Temp said: Is it a new building or an extension? There are two versions of Part L one for each. https://www.gov.uk/government/publications/conservation-of-fuel-and-power-approved-document-l just a rear extension . many thanks 34 minutes ago, ADLIan said: For a new extension wall you need 0.28 W/m2K. For new build house it depends upon the numbers that come out of the SAP assessment, looking at better than 0.25, ideally better than 0.20. After the revelations at the Grenfell Inquiry this week not sure why anyone would consider Celotex or Kingspan. what would you suggest instead please
November 10, 20205 yr We may drift off topic here. But basically both lied about fire performance, used outdated test data, changed the chemistry of products, openly confused the market.....Does not make for good reading. Celotex also admitted overstating thermal performance just after the Grenfell fire. Yes, other manufacturers are available.
November 10, 20205 yr 5 minutes ago, ADLIan said: Yes, other manufacturers are available. but that doesn't mean the other manufacturers are any better of course! it's definitely food for thought as I was planning to use some PIR in our wall make up.
November 10, 20205 yr Could try Recticel or Extratherm, they don’t appear to be caught up in this mess.
November 10, 20205 yr 47 minutes ago, Thorfun said: it's definitely food for thought as I was planning to use some PIR in our wall make up. You are not building a block of flats, the fire issue was caused by a number of failings, not just one.
November 10, 20205 yr @Dodgy-diver, here is a solution using Frametherm32, U=0.26 https://www.buildingmaterials.co.uk/knauf-earthwool-frametherm-roll-32?ps=MjA5PTgxMDgmMzY2PTEwMzYyJjM3MT0xMDU1NCY0MzE9MTU3NTI=&gclid=EAIaIQobChMIg4z05df47AIVDO7tCh35nwObEAQYASABEgIOGfD_BwE&gclsrc=aw.ds#209=8108&366=10362&371=10554&431=15752infinity=ict2~net~gaw~ar~441793144077~kw~~mt~~cmp~Shopping_Smart+Shopping_Insulation_All~ag~Insulation+Only
November 11, 20205 yr surely latest regs for smoke detectors and linked alarms will take care of any possible problem there -- law in scotland from 2022
November 11, 20205 yr 18 hours ago, A_L said: @Dodgy-diver, here is a solution using Frametherm32, U=0.26 https://www.buildingmaterials.co.uk/knauf-earthwool-frametherm-roll-32?ps=MjA5PTgxMDgmMzY2PTEwMzYyJjM3MT0xMDU1NCY0MzE9MTU3NTI=&gclid=EAIaIQobChMIg4z05df47AIVDO7tCh35nwObEAQYASABEgIOGfD_BwE&gclsrc=aw.ds#209=8108&366=10362&371=10554&431=15752infinity=ict2~net~gaw~ar~441793144077~kw~~mt~~cmp~Shopping_Smart+Shopping_Insulation_All~ag~Insulation+Only @A_L what software is that? I've been using https://www.changeplan.co.uk/u_value_calculator.php which seems to work but the software you're using looks very interesting
November 11, 20205 yr 2 hours ago, Thorfun said: what software is that? It is part of a package (NHER Evaluator) which was state of the art 2000-2010 but is no longer publically available.
November 11, 20205 yr I used BuildDeskU which I managed to download on two occasions each for 30 days free. It had a similar looking output but I used it in 2009. http://www.builddesk.co.uk/software/builddesk-u/download-builddesk-u/
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