Waste is calculated at 7 5 for a gable roof and 15 for a hip roof which are typical in the roofing industry.
How much shingles do i need for my roof.
You will then have to get the measurement of the rake of the roof.
To determine the number of squares on the gable roof above simply divide its total of 24 000 square feet by 100.
Note that in the last 3 4 years costs of roof shingles and many accessories have gone down by an average of 18 20 currently the us national average for benchmark architectural shingles is around 74 51 square or 25 per bundle.
Roof surfaces are measured in squares a square is an area of roof which measures 100 square feet.
A square of shingles is the number of shingles needed to cover 100 sq feet of roof area.
To do this you need to note that one tab will be equal to 1 foot.
For example a very steep roof on a 1 000 square foot attic will need more shingles than a lower sloped roof on the same sized attic.
320 nails will be needed to install a square of standard 3 tab shingles assuming four nails per shingle and 80 shingles per square.
However shingles are packaged in a way that they are light enough for the average person to carry around.
Keep in mind that a drip edge will be needed to protect the edge of the roof from rot vents and other materials such as flashing or caulk.
High wind areas and other types of shingles may need more.
If the existing shingles are standard 3 tab shingles you can get this measurement by taking note of the number of tabs along the eaves and ridges then determine the length in feet.