How to Estimate How Much Roofing Weighs
- 1). Use your tape measure to obtain the exact length and width of each side of your roof. Multiply the length by the width of each side to determine its square footage. Add the square footage of every section of your roof to determine the total square footage.
- 2). Choose plywood, tar paper and shingles to match the existing materials on the roof. Be sure to match the brand, type and model of each material exactly so that your final weight estimate will be as close as possible to the true weight of the roof.
- 3). Divide the total square footage of the roof by 32 to determine how many pieces of plywood are used in the roof. Weigh a piece of plywood with your scales. Multiply the weight of one piece of plywood by the number of pieces in the roof to determine plywood weight.
- 4). Look on the label on a roll of tar paper to see how many square foot each roll covers. Divide the total square footage of the roof by the square footage covered by one roll to get total number of rolls. Weigh a roll and multiply that weight by the number of rolls used on the roof.
- 5). Look on the wrapper on a package of shingles to see how many square foot it covers. Divide the total square footage of the roof by that number to get bundles of shingles used in the roof. Weigh a bundle of shingles and multiply that weight by the number of bundles used in the construction.
- 6). Add the weight of the plywood, tar paper and shingles used in the roof. Add another 10 percent to that number to account for the weight of the nails, flashing and other incidentals used in the construction of the roof to get an estimate of the total weight being supported by the roof trusses.
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