T18 and T35 sheet weight: calculate the sheet, covering and delivery separately

T18 does not guarantee identical geometry across manufacturers. Width and rib spacing alter the steel used per metre of cover. The same profile at different thicknesses also has different weights.

Record the full product designation, manufacturer, steel thickness and coating. Together they identify the correct specification row. Give the designer data for the ordered version rather than a visually similar product.

For a comparison exercise, assume T18 weighs 4.43 kg/m² of cover at 0.5 mm, 5.32 at 0.6 mm and 6.20 at 0.7 mm. Assume T35 weighs 4.71 at 0.5 mm and 6.59 at 0.7 mm. These are example assumptions, not offer specifications.

Do not use the exercise as a universal table or manufacturing tolerance. More developed steel can increase weight per covered area. Confirm every value and unit with the supplier for an actual delivery.

Part of the sheet width lies within the side lap. Total area therefore exceeds effective cover for the same length. Multiplying weight per covered square metre by total area mixes incompatible bases.

Keep the complete unit when copying quotations: kg/m², kg per linear metre or kg per sheet. An unspecified area basis can distort the result. Clarify it before booking transport and lifting equipment.

For weight per covered area, use effective width and length. The assumptions 4.43 × 1.10 × 6 give 29.238 kg, or about 29.24 kg. Packaging is excluded from this calculation.

Handling a six-metre element also depends on deflection and wind. Kilograms alone do not determine crew size or support points. Plan lifting according to the instructions for that particular format.

For an illustrative 200 m² of cover, 4.43 kg/m² gives 886 kg and 6.59 kg/m² gives 1,318 kg. The actual order also needs cutting losses, end laps, spare material and flashings.

Size equipment for the packaged transport unit, including protective materials. Check length and centre of gravity from delivery information. Do not place a whole package on a floor without confirming local load capacity.

Roof design also includes battens, decking, insulation, equipment, snow and wind. Lightweight sheets still need effective uplift restraint. Comparing covering weights cannot replace checking connections.

During renovation, reducing weight does not repair weakened rafters. Thicker steel likewise does not permit arbitrary batten spacing. Check strength and deflection for the actual support arrangement.

Keep the source-document version and product designation with the schedule. Resolve discrepancies before approval: coating, thickness or area basis may differ. Retain the supplier’s confirmation.

Record sheet weight, total sheet material and packaged delivery separately. They support different decisions. Clear units help prevent mistakes in manual handling, vehicle selection and crane planning.