Estimating Hip Roofs
Estimating Hip Roofs- Rafters Pitch = 24⁰ Note – Change of Layout of Ceiling Joists to Accommodate Creepers Determine No of Rafters 12 500/ 600 = 20.833 = 21 + 1 = 22 Rafters each side = 44
Determine Rafter Length Span = 6900
Determine Rafter Length Span = 6900 Half Span = 3450
Determine Rafter Length Span = 6900 Half Span = 3450 Run = 3450
Determine Rafter Length Span = 6900 Half Span = 3450 Run = 3450 – 9.5 = 3440.5 Run of Eaves = 600 Total Run = 3450 + 600 = 4050 Total Length =4050/ cos 24 =4433 + offset =4473
Estimating Sheet
Estimating Hip Roof - Ridge Pitch = 24⁰ Overhang 450 Rafter 90 x 45 F7 600 c to c Ridge 140 x 19 Purlin 90 x 70 F7 Ridge Runs Between Crown End 12.500 -2 x 3600 = 5300 5300 + ½ Rafter Thickness for each hip end 5300 + 45 =5345 mm
Estimating Sheet
Estimating Hip Roof - Purlin Pitch = 24⁰ Overhang 450 Rafter 90 x 45 F7 600 c to c Tiled Roof Ridge 140 x 19 Purlin 90 x 70 F7 Spacing 2200 centres 1 Row Purlins at Centre Span Deduct ¼ span for every hip 12500 – 1725 – 1725 = 9050 allow 150 for joints = 9200 6900 – 1725 – 1725 = 3450
Estimating Sheet
Estimating Hip Roof – Hip Rafter Pitch = 24⁰ Overhang 450 Rafter 90 x 45 F7 600 c to c Hip 140 x 19 Ridge 140 x 19 Purlin 90 x 70 F7 Method 1 Hip = √(Rise² + ((Half Span + O/H) x 1.414)² Hip = √(1.803² + ((3450 + 600) x 1.414)² ) Hip = √(3.251 + 32.795) Hip = 6.003 + 0.15 for Plumb Cut Hip = 6.153 Method 2 Hip = √(Total Rafter² + (Half Span + O/H)² Hip = √(4433² + (3450 + 600)² ) Hip = √(19.551 + 16.403) Hip = 6.004 + 0.15 for Plumb Cut Hip = 6.154
Estimating Sheet
Estimating Gable Roof - Struts Pitch = 24⁰ Overhang 450 Rafter 90 x 45 F7 600 c to c Tiled Roof with Flush Gable & Raking Eaves Ridge 140 x 19 Purlin 90 x 70 F7 Span 2700 Struts are Difficult to Estimate Develop a Best Guest Method Determine No Required 9.050/2700 =3.4= 4= 5 Each Side Determine No Required 3.450/2700 =1.28= 2= 3 Each Side
Estimating Gable Roof - Struts Pitch = 24⁰ Overhang 450 Rafter 90 x 45 F7 600 c to c Tiled Roof with Flush Gable & Raking Eaves Ridge 140 x 19 Purlin 90 x 70 F7 Span 2700 Length Half Rise x √2 x √2 (3.450/2 x tan24) x 2 0.768 x 2 = 1.536
Estimating Sheet
Estimating Gable Roof – Collar Ties Pitch = 24⁰ Overhang 450 Rafter 90 x 45 F7 600 c to c Tiled Roof with Flush Gable & Raking Eaves Ridge 140 x 19 Purlin 90 x 70 F7 Span 2700 Collar Ties 90 x 35 Collar Ties on Every 2nd Rafter On top of Purlins Length of Ridge / Rafter Spacing / 2 22/2 = 11+1 @ HALF SPAN 12 @ 3450
Estimating Sheet
Estimating Tile Quantities Pitch = 24⁰ Overhang 450 Rafter 90 x 45 F7 600 c to c Tiled Roof with Flush Gable & Raking Eaves Ridge 140 x 19 Purlin 90 x 70 F7 Span 2700 Collar Ties 90 x 35 Calculate Roof Area
Determine Rafter Length Span = 6900 Half Span = 3450 Run = 3450 – 9.5 = 3440.5 Run of Eaves = 600 Total Run = 3450 + 600 = 4050 Total Length =4050/ cos 24 =4433 + offset =4473
Estimating Tile Quantities Pitch = 24⁰ Overhang 450 Rafter 90 x 45 F7 600 c to c Tiled Roof with Flush Gable & Raking Eaves Ridge 140 x 19 Purlin 90 x 70 F7 Span 2700 Collar Ties 90 x 35 True Length of Rafter = 4433 Area of Roof = 4433 x (12.800 +2 x 0.45) x 2 = 121.464 x 7 tiles per sqm = 850.249