If you have a simple gable roof, you’ll only need to measure and sum up the 2 planes of the roof. If your roof has dormers, hips, or other complex elements, don’t forget to take the area of those additional parts of the roof into account. Because of these slopes and pitches, the square footage of your roof will not be the same as the square footage of your home. [2] X Expert Source David BitanRoofing Contractor & Maintenance Professional Expert Interview. 14 July 2020. Websites like Eagleview use satellite imagery to help you safely measure your roof. [3] X Expert Source David BitanRoofing Contractor & Maintenance Professional Expert Interview. 14 July 2020.
If your roof has hips and valleys, make it 15% because of waste in cutting shingles to fit the valleys.
If you’re just replacing some old shingles, you may not need to purchase underlayment. However, this is a must if you’re installing a new roof.
If you’re using #15 underlayment and your roof slope is greater than 4:12, use 1 layer. If the slope is between 3:12 and 4:12, double the amount and put down 2 layers.
For high-wind areas, use 6 nails per shingle, or 480 nails per square. Inquire at the hardware store regarding the size of nail you’ll need and how many pounds or kilograms you’ll need of that size; the number of nails per pound or kg differs. The nails should be long enough to go 3⁄4 inch (1. 9 cm) into the roof. Inquire at the hardware store regarding the amount of underlayment nails required. Always use 1 in (2. 5 cm) nails. The nails should be 12 inches (30 cm) apart along the edges and 24 inches (61 cm) apart in the middle of the underlayment strip.
Venting. A venting system plays a crucial role in maintaining the integrity of the roof during hot and cold weather. [8] X Expert Source David BitanRoofing Contractor & Maintenance Professional Expert Interview. 14 July 2020. *Flashing. Aluminum or steel material that is used to cover roof joints and prevent water from getting in. [9] X Research source Ice/water shield. An ice shield is only necessary if you live in an area that is prone to ice and snow in the winter. [10] X Research source Boots. These are required to go around any pipes sticking through the roof. Delivery charge for your materials (if there is one).
