Roof footprint (ground floor area)
Measure the outside footprint of the house at ground level including any garage or attached structures under the roofline.
Roof pitch
Medium pitch (4/12 to 6/12) is the most common for residential homes. The steeper the roof, the more material you need.
Roof shape
A gable roof has two slopes meeting at a ridge. The simplest shape with the least waste.
Roofing is a high-risk DIY project. Working at height requires proper safety equipment including harnesses, roof jacks, and non-slip footwear. Always check local permit requirements before replacing a roof. When in doubt, get at least two contractor quotes before deciding to DIY.