Roofing is weighed by the “square” — the material to cover 100 square feet. Weight matters because the roof structure must support it. This chart compares common materials.
| Material | Weight per square |
|---|---|
| Asphalt 3-tab shingles | 230 – 250 lb |
| Architectural asphalt | 350 – 450 lb |
| Wood shakes | 350 – 450 lb |
| Metal (steel/aluminum) | 50 – 150 lb |
| Concrete tile | 600 – 1000 lb |
| Clay tile | 600 – 1100 lb |
| Slate | 800 – 1500 lb |
One square = 100 sq ft. Heavy materials like tile and slate can weigh several times what asphalt does — the framing must be designed for it, often requiring an engineer.
FAQ
Does roofing material weight affect structural requirements? Yes. Heavier roofing materials like tile or slate require the roof structure (rafters, trusses, and sheathing) to be designed or verified for the additional dead load, which is why a material swap on an existing roof often needs a structural check first.