Flat Roof Joist Check
Flat Roof Construction.
Felt		5	kg/m2
none 12mm ply / OSB 2 x 12mm ply / OSB (Warm deck) 18mm chipboard 22mm chipboard 15mm t&g floor boarding 38mm chipboard		8	kg/m2
Firrings		6	kg/m2
100 x 50 timbers 150 x 50 timbers 200 x 50 timbers 225 x 50 timbers		12	kg/m2
Insulation		6	kg/m2
No plasterboard 1 layer 12.5mm plasterboard 2 layer 12.5mm plasterboard 3 layer 12.5mm plasterboard 4 layer 12.5mm plasterboard		15	kg/m2
None Ceiling (5 kg/m2) Services (3 kg/m2) General contingency (8 kg/m2)		0	kg/m2
Total		42	kg/m2
Dead Load		0.39	kN/m2
Design Snow load 0.6 Design Snow load 0.75 Design Snow load 1.0		0.75	kN/m2
Total		1.14	kN/m2
Flat Roof Joist (Aligns with the spreadsheet)	Data Entry
Clear Span		m eff	5.2
Centres		m
Trial Depth		mm
Trial Width		mm
timber grade	C16 C24
		stress	deflection
Joist satisfactory		58.0%	100.0%