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

Question

The following data can be extracted from the model:



All of the 24?? × 48?? windows are in the exterior walls. Only 2 of the 36?? × 72?? windows are in the exterior walls. The 20 of the 36?? × 84?? doors are in the interior walls. The other doors are in the exterior walls.



What will be an ideal response?

Answer 1

Determine the materials needed for the exterior walls. From the model we see that we need 1,818 square feet of exterior wall, which requires 3.5-inch batt insulation. It may be calculated manually as follows:



Area of wall = 241? × 9?1?? = 2,189 sf



Area of openings = 34 × 2 × 4 + 2 × 3 × 6 + 1 × 3 × 7 + 1 × 6 × 7 = 371 sf



Area of wall to be insulation = 2,189 sf – 371 sf = 1,818 sf



Assume 56-foot-long rolls.



Effective coverage per roll = 16? × 56? / 12 in per ft = 75 sf



Rolls of insulation = 1,818 sf of walls / 75 sf of coverage per roll = 24.24 rolls



Use 25 rolls



Determine the materials needed for the interior walls. From the model we see that we need 3,483 square feet of interior walls, which requires 3.5-inch batt insulation.



It may be calculated manually as follows:

Area of wall = 463? × 9?1?? = 4,206 sf



Area of openings = 12 × 3 × 6 + 20 × 3 × 7 = 636 sf



Area of wall to be insulation = 4,206 sf – 636 sf = 3,570 sf



This is close to the number calculated by the model. This is a good time to discuss the potential pitfalls of using the model for takeoffs. Clearly there is a difference in the way the wall area is calculated.



Assume 56-foot-long rolls.



Effective coverage per roll = 16? × 56? / 12 in per ft = 75 sf



Rolls of insulation = 3,483 sf of walls / 75 sf of coverage per roll = 46.44 rolls



Use 47 rolls



The area of the

ceiling equals the area of the floor slab. The following quantities can be extracted from the model.



The area of the ceiling from the model is 3,600 sf. Alternatively it may be calculated as follows:



Area = 72 ? × 50 ? = 3,600 sf



Assume 56-foot-long rolls.



Effective coverage per roll = 24? × 56? / 12 in per ft = 112 sf



Rolls of insulation = 3,600 sf of roof / 112 sf of coverage per roll = 32.14 rolls



Use 33 rolls