Step 1
Measure the width of the roof with the tape measure. Have an assistant hold one end of the tape measure and walk across to the other end of the roof and write down the width of the roof.
Step 2
Measure the length of the roof with the tape measure. With an assistant holding one end of the tape measure, walk across to the other end of the roof and write down the length of the roof.
Step 3
Multiply the width of the roof by the length of the roof to find the square footage. For example, a roof that measures 100 feet wide by 100 feet long is multiplied (100 x 100 = 10,000 square feet) giving you 10,000 square feet. You need to buy and install 10,000 square feet of tapered insulation panels to cover your roof.
Step 4
Contact the architect who designed the building and ask for the insulation plans. The architect can then forward you the insulation plans which show the height of the insulation board required. Only a licensed architect can design and tell you the height of the insulation board required for a tapered insulation system because she has to submit the insulation plans to the local building department for approval.