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Enter your dimensions and get an estimated quantity for your job. Add a wastage allowance, then request a trade quote when you are ready.
Enter the roof area or perimeter to calculate quantities.
Browse the catalogue or send your list through for a trade quote.
Estimate roofing felt, membrane, guttering and trim quantities. Enter the roof dimensions or the run lengths and the calculator returns the rolls, lengths or packs you need to order.
20 m² flat roof felt
Needs roughly 2 rolls of torch-on felt with a 75 mm lap.
15 m gutter run
Needs 4 gutter lengths at 4 m each plus fittings.
30 m² breathable membrane
Needs roughly 1–2 rolls depending on roll width.
The calculator gives you a sensible starting quantity. For structural work, always confirm the specification and grade with your engineer or building control before ordering. We stock the standard trade lines and can source specialist grades or sizes with short lead times.
Working from drawings? Send us your dimensions, schedule or take-off and we will check the estimate, advise on the right product grade and wastage allowance, and book a delivery slot that matches your programme. We reply the same business day with a written trade quote.