P4PCFF1 Roof, Insulation At Ceiling Level Build Up Masonry Party Wall Separating Wall and Roof 2 x 100mm Aircrete Block (0.15W/m²K) Party (Separating) Wall Max. 100mm cavity fully filled with insulation (0.044W/mK) density up to 40kg/ m3 400mm Insulation (λ = 0.044W/mK) at Ceiling Level Architect downloads p4pcff1_cad_file.dwg69.1 KB Registered Detail certificates p4pcff1_certificate.pdf639.89 KB rcd_worksheet_172.pdf340.6 KB