Flat Roofing

21 articles

• Cold Flat Roof Problems: Condensation, Rot & Warm Deck Fix
  Why cold deck roofs fail: interstitial condensation, 1:150 ventilation requirement rarely achievable, timber rot progression, blistering diagnosis, conversion to warm deck options
• EPDM Rubber Roof Installation Guide: Substrate & Detailing
  EPDM rubber roofing installation: 18mm OSB3/marine ply substrate, 1.2–1.5mm EPDM membrane, bonding adhesive both surfaces (flash off), 75mm seam tape laps with primer, termination bars at perimeter; NFRC CoP 2; warranty 20–25 years
• EPDM Rubber Roofing: Bonded vs Mechanical Fixing Guide
  EPDM bonded vs mechanically fixed: seam tape (75mm min overlap, EPDM primer then butyl tape), termination bars at ≤200mm centres, 150mm upstands, 1:40 recommended fall
• Fire Safety for Flat Roofs: Part B & BROOF(t4) Guide UK
• Flat Roof Building Regs Part C: Upstands & Weatherproofing
  Part C weather resistance: 150mm minimum upstands, lead/aluminium flashings with 75mm overlap and 25mm chase, drainage falls, penetration detailing, NFRC CoP compliance satisfies Part C
• Flat Roof Drainage Design: BS EN 12056 & Fall Requirements
  BS EN 12056-3 design rainfall (75mm/hr primary, 150mm/hr overflow), minimum falls 1:80, mandatory overflow provision, outlet sizing by roof area, green roof drainage considerations
• Flat Roof Falls & Drainage: BS 6229 Sizing Guide UK
  Flat roof falls and drainage per BS 6229 / BS EN 12056-3: minimum 1:80 design fall, 1:40 recommended for new build (tolerance); outlet sizing 75mm = 40m², 110mm = 80m²; overflow weirs / scuppers mandatory on parapets; tapered insulation for retrofit fall
• Flat Roof Inspection Guide: What to Look For & Report Format
  Systematic survey methodology, felt/EPDM/GRP failure modes, IR thermography and ELD techniques, RICS three-grade condition rating, condition report format for customer-facing use
• Flat Roof Insulation: Warm Deck vs Cold Deck UK Guide
• Flat Roof Membrane Types UK: EPDM, GRP, Felt & TPO Guide
• Flat Roof Parapet Details: BS 6229 Upstands & Copings
  Parapet upstand minimum 150mm above finished roof level (BS 6229:2018), coping stone DPC and drip detail, lead/GRP/EPDM flashing at parapet base, thermal bridging Ψ-values, five most common failure modes
• Flat Roof Repair vs Replacement: When to Strip & Relay
  Patch repair limitations on aged felt, 20% blistering threshold, overlay vs strip (Part L 25% renovation trigger, 0.18 W/m²K), Party Wall Act notice, cost-benefit framework
• Flat Roof Rooflights: Upstand Heights & U-Values UK
  150mm upstand at rooflight kerb (BS 6229:2018), timber vs prefabricated kerb, membrane termination, U-value ≤1.6 W/m²K for replacement (Part L 2021), permitted development 150mm projection limit, condensation diagnosis
• Flat Roof U-Values Part L: 0.18 W/m²K Insulation Guide
  Part L 2021 U-value target 0.18 W/m²K: 130–150mm PIR or 175–210mm EPS, tapered insulation average U-value calculation, thermal bridging at parapets (ψ values)
• Green Roof Build-Up: Extensive vs Intensive Systems UK
  Layer-by-layer green roof build-up (VCL → insulation → FLL-tested root barrier → drainage cell → filter fleece → substrate), extensive 60–150 kg/m² vs intensive 200+ kg/m², BS 8579:2019, BNG/Environment Act 2021
• GRP Fibreglass Flat Roof: Installation & Defects Guide
  GRP installation: 450g/m² CSM, 1–2% MEKP catalyst, key coat timing (hardened but not fully cured), topcoat application, common defects (delamination, crazing, dry patches)
• Inverted Roof System: XPS Insulation & Ballast Guide UK
  XPS insulation above waterproofing membrane, 100kg/m² minimum ballast, ISO 13165 moisture correction factor (fX = 0.04 W/m²K), 200–250mm XPS for 0.18 W/m²K target, no VCL needed
• NFRC Flat Roofing Standards: UK Codes of Practice Guide
  NFRC CoP 1 (built-up felt), CoP 2 (single-ply EPDM/PVC), CoP 3 (mastic asphalt), CoP 4 (cold-applied liquid/GRP): falls 1:80 minimum, 150mm upstands, warranty provider alignment
• Part L Flat Roof U-Values: Insulation Thickness Guide
• Torch-On Felt Roofing: SBS vs APP & Layer Build-Up Guide
  SBS vs APP modified bitumen: 2-layer minimum, 75mm side laps, hot works permit, dedicated fire watcher, 1-hour post-completion fire watch, NFRC CoP 1 compliance
• Warm Flat Roof Construction: Insulation & VCL Detail UK
  Warm deck build-up: deck → VCL → PIR insulation → waterproofing membrane; VCL position (below insulation, not above); tapered insulation for falls; 0.18 W/m²K Part L target