{
  "version": "2026-08-28.1",
  "checked_date": "2026-08-28",
  "geography": "United Kingdom product literature; Irish worked method examples identified separately",
  "sources": {
    "tp10": {"title":"Kingspan Thermapitch TP10 GB brochure, page 5", "url":"https://www.kingspan.com/content/dam/kingspan/kil/products/thermapitch-tp10-gb-and-ireland/kingspan-thermapitch-tp10-brochure-en-gb.pdf"},
    "ga4000": {"title":"SOPRATHERM GA4000 technical data sheet TDS-UK-INSUK0025.a/EN", "url":"https://my.assets-library.com/asset/c9934f2b-78e7-4832-b26e-e4433d1b6e19/TDS-SOPRATHERM-GA4000.pdf"},
    "ga4000-name": {"title":"Soprema: GA4000, previously Celotex", "url":"https://www.soprema.co.uk/products/sopratherm-ga4000"},
    "flexi": {"title":"ROCKWOOL Flexi technical sheet, November 2025, page 3", "url":"https://www.rockwool.com/syssiteassets/rw-uk/downloads/datasheets/flexi.pdf"},
    "flexi-range": {"title":"ROCKWOOL Flexi UK listed product variants", "url":"https://www.rockwool.com/uk/products/flexi/"},
    "seai": {"title":"SEAI DEAP guidance, pages 76-79: worked roof examples", "url":"https://www.seai.ie/sites/default/files/publications/DEAP_Guidance_Document.pdf"},
    "surface": {"title":"UK government moisture research, modelling surfaces, page 12", "url":"https://assets.publishing.service.gov.uk/media/5d25e21d40f0b611b6809803/R3_M3_Calculation_methods.pdf"},
    "combined": {"title":"Santos et al., Energies 2020, section 2.1.1: combined method and limits", "url":"https://www.mdpi.com/1996-1073/13/4/840"},
    "ht": {"title":"ht conduction library: k_to_R", "url":"https://ht.readthedocs.io/en/latest/ht.conduction.html#ht.conduction.k_to_R"}
  },
  "products": [
    {"id":"tp10","name":"Kingspan Thermapitch TP10","source":"tp10","range_source":"tp10","thickness_mm":[25,30,40,50,60,70,75,80,90,100,110,120,125,130,140,150],"lambda_w_mk":[0.022,0.022,0.022,0.022,0.022,0.022,0.022,0.022,0.022,0.022,0.022,0.022,0.022,0.022,0.022,0.022],"declared_r":[1.1,1.35,1.8,2.25,2.7,3.15,3.4,3.6,4.05,4.5,5,5.45,5.65,5.9,6.35,6.8],"note":"UK brochure thicknesses, not a live stock list. Thermal properties are not installation approval."},
    {"id":"ga4000","name":"SOPRATHERM GA4000 (previously Celotex)","source":"ga4000","range_source":"ga4000","thickness_mm":[50,60,70,75,80,90,100],"lambda_w_mk":[0.022,0.022,0.022,0.022,0.022,0.022,0.022],"declared_r":[2.25,2.7,3.15,3.4,3.6,4.05,4.5],"note":"Technical sheet controls these values. The captured product-page 100 mm R of 5.50 conflicts with the sheet's 4.50; it is not used."},
    {"id":"flexi","name":"ROCKWOOL Flexi","source":"flexi","range_source":"flexi-range","thickness_mm":[50,60,70,90,100,120,140,180],"lambda_w_mk":[0.038,0.038,0.038,0.038,0.038,0.038,0.035,0.035],"declared_r":[1.3,1.55,1.8,2.35,2.6,3.15,4,5.1],"note":"Listed UK variants only. Lambda changes from 0.038 to 0.035 at 140 mm; no interpolation across unlisted thicknesses."}
  ],
  "reuse": "Original calculations and selection: CC BY 4.0, attribute Inzonex and link this page. Manufacturer property facts remain attributed to their sources; no rights are granted over manufacturer documents, images or trademarks. Not a manufacturer-endorsed calculator.",
  "scope": "Steady-state plane layers, optionally one repeating timber layer. Excludes metal framing, ground-coupled floors, windows, junction psi values, moisture and fire design. No automatic fastener, air-gap or inverted-roof correction. Not a compliance certificate."
}