Determine materials required to complete the roofing for the Real Estate Office in Appendix E. Using the labor rates from Problem 7-31 and the crew rate for the roofing crew from Problem 7-32 determine the cost to roof the building.

Question

The following data can be extracted from the model:

Answer 1

Determine the area of the roofing manually:

Length = 1?8?? + 72? + 1?8?? = 75?4??

Length = 1?8?? + 50? + 1?8?? = 53?4??

Area of sheathing = 75?4?? × 53?4?? × 1.12 = 4,499 sf – the difference is due to rounding of the 1.12

sf of felt in a roll = 36? × 134? / 12 in per ft = 402 sf

Assume a 6-inch lap.

Exposure = 36? – 6? = 30?

Roll coverage = 402 sf × 30? / 36? = 335 sf

Rolls of felt required = 4,499 sf / 335 sf per roll = 13.4 rolls – Use 14 rolls

Starter course = 75?4?? + 53?4?? + 75?4?? + 53?4?? = 257?4?? – Use 258?

Starter course = 258? × 5? / 12 in per ft = 108 sf = 1.08 squares

Squares of roofing = 44.99 squares + 1.08 squares = 46.07 squares

Length of hips = [(53?4??/2)2 + (53?4??/2)2 + (53?4??/2 × 6 /12)2]0.5 = 40?

Length of ridge = 75?4?? – 53?4?? = 22?

Ridge shingles = 4 × 40? + 22? = 182?

Ridge shingles = 182? × 12 in per ft / 5? per shingle = 437 pieces

Drip edge = 75?4?? + 53?4?? + 75?4?? + 53?4?? = 257?4?? – Use 258?

The roof requires three pipe flashings

Determine the required venting area

Area of roof = Drip edge = 75?4?? x 53?4?? = 4,017 sf

Area of vents = 4,017 sf /300 sf of roof per sf of vent = 13.4 sf = 1,928 in2

Use Master Flow static roof vents bronze aluminum square roof louver, which provide 50 square inches per vent.

Number of vents = 1,928 in2 / 50 in2 per vent = 39 vents