metal roof L feet mounting
Aluminum L feet metal roof mounting
Material: The industry standard is AL6005-T5 aluminum alloy. This material offers an excellent strength-to-weight ratio and is highly corrosion-resistant. High-quality versions feature an anodized surface treatment (typically 10-15 microns thick) to withstand salt spray and harsh weather for 25+ years.
Dimensions: A standard L-foot usually has a base of 80mm x 40mm, but heights vary significantly (typically 80mm to 150mm) depending on roof clearance needs.
Load Capacity: A single, properly installed L-foot can withstand significant forces, often rated for wind loads up to 1.4 kN/m² (approx. 60m/s wind speed) and similar snow loads.
Purlin Integrity: For penetrating mounts, hitting the structural purlin is non-negotiable. Attaching an L-foot only to the thin metal sheet of the roof will result in catastrophic failure during high winds.
Thermal Expansion: Metal roofs expand and contract with temperature changes. Quality L-feet often utilize slotted holes in the base, allowing the roof to move slightly without stressing the bolt or the racking system.
Corrosion Control: To prevent galvanic corrosion (where two dissimilar metals react), stainless steel hardware (SUS304 or 316) is used for the bolts, while the foot itself remains aluminum.
