Roof geometry affects measuring and material quantities; even a flat roof needs appropriate drainage.
Flat or low-slope roof
“Flat” usually means a low slope, not necessarily zero slope. Drainage, waterproofing, outlets and junction details must suit the building system and local requirements.
Mono-pitch roof
One main plane slopes in a single direction. Once its horizontal projection and angle are known, a geometric area estimate is possible. That does not mean every membrane or roof tile is compatible with the pitch.
Gable roof
Two slopes meet at a ridge. If they share the same angle, the total area can be estimated from the horizontal projection and pitch. Different angles require separate calculations for each face.
Hip roof
Roof planes descend in four directions. The geometry creates ridges, hips, valleys and special cuts. A simple area estimate cannot replace the actual installation layout.
Understanding pitch
Pitch describes rise relative to a horizontal run. It can be expressed in degrees or as a percentage, but the numbers are not interchangeable: a 100% slope equals 45°, not 100°.
Choosing materials
Check minimum permitted pitch, wind exposure, climate, fastening, underlay, weight and the manufacturer's technical specifications. Never select a roof system solely from an estimated tile count.
TechoExacto models four basic roof forms and provides approximate quantities, not structural or weatherproofing approval.
Try it in TechoExacto
Enter your own measurements and compare the result. Actual quantities depend on your materials.