Shed Roof Felt Calculator: How Many Rolls Do I Need?
By the Professional Roofers team
Updated 2026 · Independent cost guide
Shed felt is sold by the roll, but the number of rolls you need is set by how the strips cut out of each roll, not by the roof area. An 8 by 6 foot apex shed with 1 m slopes has only about 5.3 m² of roof, which looks like one 10 m roll. Once the side laps and the ridge strip are counted, though, it takes five strips of about 2.5 m, 12.7 m of felt in all, so you need two rolls. Enter your roof and this works out the courses, the cut list, the rolls to buy and the clout nails, for a pent or an apex shed.
How much shed felt do you need?
Strips run along the length of the roof, starting at the eaves and lapping up the slope. On an apex roof a final strip is laid centrally over the ridge so it laps down both sides. Where a run is longer than one roll, two lengths are joined with a 150mm end lap. This is an ordering estimate; follow the fixing instructions on your felt.
Want costs like this each month?
Join the Roofline brief for current UK prices and quote-reading tips.
More from Professional Roofers
How Much Does a New Roof Cost in the UK in 2026?
What a new roof really costs in the UK in 2026, broken down by house size, material and the hidden extras, plus how to check you are being quoted fairly.
Chimney Repointing and Repair Cost UK (2026)
What chimney repointing cost is in the UK in 2026, why scaffolding drives the price, and how repointing compares to rebuilding, flashing and pot repairs.
Roof Inspection and Survey Cost UK: What's Checked and the Price
Roof inspection cost UK 2026: what a ground, ladder or drone survey checks, typical prices for each, and when a written roof report is worth paying for.