How to do a roofing takeoff

Read the spec first

Find your roofing section in Division 07. A thermoplastic membrane roof is 07 54 00. Read 07 62 00 Sheet Metal Flashing and Trim. Note the membrane thickness, the attachment method, the insulation and the cover board. Read the warranty terms. The warranty can set the system more than the drawings do.

Sheets and schedules that carry the count

• The roof plan. It shows areas, slopes, drains, crickets and equipment.
• The roof details: edges, parapets, curbs, drains and penetrations.
• The wall sections. They show the parapet height and the roof assembly.
• The tapered insulation plan, if the set has one.
• The mechanical and plumbing roof plans. They show more penetrations.
• The structural roof plan, for the deck type and slope.

Steps in order

1. Measure each roof area. Keep different assemblies apart.
2. Adjust the area for slope on steep roofs.
3. Measure the perimeter. Split it by edge type: parapet, gravel stop or gutter.
4. Measure the parapet height for wall flashing.
5. Measure coping, edge metal, gutters and expansion joints by length.
6. Count drains, scuppers, curbs, pipes, hatches and other penetrations.
7. Work out the insulation by layer. Send the tapered layout to your supplier.
8. Add walkway pads, fasteners and adhesive by area.

Count, length, area or volume

• Count: drains, scuppers, curbs, pipe penetrations, hatches and downspouts.
• Length: edge metal, coping, base flashing, gutters and expansion joints.
• Area: membrane, insulation, cover board, vapor barrier and walkway pads.
• Volume: seldom used. Some estimators check tapered insulation in board feet.

Conflicts to find, and what to exclude

• The spec states one insulation value. The wall section shows a different thickness.
• The roof plan shows slope arrows. Nothing says if the structure or the insulation slopes.
• The mechanical roof plan shows more curbs than the architectural roof plan.
• Sheet metal appears in the roofing section and again in 07 62 00.
• The warranty needs parts that the details do not show.

State who supplies wood blocking, roof curbs and roof drains. Qualify deck repair and wet insulation on reroof jobs. Exclude lightning protection and equipment supports unless your section includes them.

Trade takeoffs · Updated 11 Nov 2026