CSLB C-39 Roofing ContractorSteep-Slope RoofingEasy
A roofing crew is installing a new metal roof using corrugated panels. To ensure proper drainage and prevent water infiltration, what is the minimum recommended roof slope for these types of panels?
- A4:12
- B2:12
- C1:12
- D3:12
Show answer & explanationAnswer & explanation
Correct answer: D. 3:12
Corrugated metal panels require a minimum slope of 3:12 to ensure adequate water runoff and prevent ponding or back-siphonage, which can lead to leaks.
Why the other options are wrong
- A. 4:12 is a good slope for metal roofing but not the minimum required for corrugated panels.
- B. 2:12 is often considered the absolute minimum for some standing seam systems, but 3:12 is safer and more common for corrugated.
- C. 1:12 is generally too low for corrugated metal panels and can lead to water retention.
Corrugated Metal Panel Minimum Slope
The lowest acceptable roof pitch for corrugated metal panels to ensure effective water drainage and prevent leaks.
- Critical for weather performance.
- Prevents water ponding and back-siphonage.
- Varies by panel profile and manufacturer.
Memory trick: Slope it right, keep the water out of sight.