CSLB C-39 Roofing ContractorSteep-Slope RoofingMedium
A roofer is preparing to install standard 5-V Crimp metal roofing panels on a residential garage. The roof has a pitch of 3:12. To ensure proper water shedding and compliance with building codes, what is the minimum slope required for 5-V Crimp metal panels without special sealing or underlayment considerations?
- A3:12
- B1:12
- C2:12
- D0.5:12
Show answer & explanationAnswer & explanation
Correct answer: C. 2:12
5-V Crimp metal roofing panels generally require a minimum slope of 2:12 to ensure adequate water runoff and prevent ponding or backflow, assuming standard installation without additional sealing. While 3:12 is steeper, 2:12 is the typical minimum.
Why the other options are wrong
- A. 3:12 is a suitable slope, but 2:12 is the minimum, making 3:12 not the *minimum* required.
- B. 1:12 is generally too low for 5-V Crimp panels; it might be acceptable for some standing seam systems with sealant.
- D. 0.5:12 (1/2:12) is too low for 5-V Crimp and would require a standing seam or specialized low-slope metal system.
Metal Panel Minimum Slope
Metal roofing panels have minimum slope requirements that vary based on panel profile and fastening method to ensure effective water shedding.
- Exposed fastener panels (like 5-V Crimp) typically require steeper slopes than standing seam.
- Minimum slopes can range from 0.25:12 for some standing seam to 3:12 for certain exposed fastener systems.
- Lower slopes may require additional sealing or a continuous underlayment.
Memory trick: Metal's tilt: the flatter the sheet, the tighter the seal.