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ROOFING · CSI DIVISION 07TRADE · ROOFING

Squares, ridge LF, flashing, drains — by the roof plane.

PlanSwift counts roof area off the floor plan footprint and forgets the pitch correction. BuildBid reads the roof plan and the spec section together.

Roofing takeoff (CSI Division 07) is a planes-and-perimeter problem. Steep-slope assemblies (shingles, tile, metal panels) ship by the square (100 SF of slope area, not footprint), measured plane-by-plane with the pitch correction applied. Low-slope membrane (EPDM, TPO, modified bitumen, built-up) ships by SF of installed area per ply. BuildBid reads the roof plan (A-2xx series), the roof spec (07 31 / 07 41 / 07 50 / 07 53), and the manufacturer details together so the assembly, the fasteners, and the warranty class land in the same line item.

Perimeter is its own line item set — not rolled into the field. Ridge cap, hip cap, valley flashing, eave drip, rake trim, step flashing at walls, counter-flashing, and gravel stop each have their own LF and their own labor rate. Penetrations (plumbing vents, mechanical curbs, skylights, hatches) are counted EA with the flashing kit specified per the manufacturer's detail.

Drainage is sized from the roof plan and the plumbing riser diagram. Roof drains (primary + overflow), scuppers, gutters, downspouts, and conductor heads each surface as their own assembly. Tapered insulation packages — the most-missed line on low-slope work — are computed from the slope diagram (0.25 in/ft typical) and priced by ISO board by thickness.

Underlayment and substrate prep are counted separately. Self-adhering ice-and-water membrane at eaves and valleys, synthetic underlayment over the field, cover board over rigid insulation, vapor retarder beneath — each pulled from the spec section and the wall section details.

Try on a sample roof packageSee sample takeoff
WORKFLOW · HOW IT ACTUALLY RUNS5 STEPS
  1. STEP 01

    Upload roof plan + roof spec sections

    Roof plan (A-2xx series), roof slope diagram, wall section details (showing roof edge, eave, ridge, valley assemblies), penetration schedule. Specs 07 31 (shingles), 07 41 (metal panels), 07 50 (membrane), 07 53 (EPDM / TPO), 07 60 (flashing + sheet metal), 07 71 (roof accessories), 07 84 (firestopping at penetrations) cross-read for assembly, fastener pattern, and warranty class.

  2. STEP 02

    Slope-corrected SF by plane

    Each roof plane measured from the plan (footprint SF) then pitch-corrected: 4/12 → ×1.054, 6/12 → ×1.118, 8/12 → ×1.202, 12/12 → ×1.414. Steep-slope output in squares (100 SF). Low-slope output in installed SF per ply (BUR can run 4 plies). Each plane traceable to the sheet.

  3. STEP 03

    Perimeter LF by type

    Ridge cap (LF along ridge), hip cap (LF along hip), valley flashing (LF along valley), eave drip (LF along eave), rake trim (LF along rake), step flashing at walls (LF where roof meets wall), counter-flashing (LF along masonry / through-wall), gravel stop / fascia trim (LF along low-slope perimeter). Each LF labeled with its profile and gauge.

  4. STEP 04

    Penetrations + drainage by EA + LF

    Plumbing vents (EA + boot type), mechanical curbs (EA + LF perimeter for curb flashing), skylights (EA + LF curb flashing), roof hatches (EA), equipment supports. Drainage: primary drains (EA), overflow drains (EA), scuppers (EA), gutters (LF), downspouts (LF), conductor heads (EA). Tapered insulation: SF × average thickness → board count by ISO thickness.

  5. STEP 05

    Underlayment, substrate, warranty class

    Ice-and-water membrane at eaves and valleys (LF × 36 in coverage), synthetic underlayment over field (SF), cover board over rigid insulation per low-slope spec (SF + board type), vapor retarder (SF). Warranty class read from spec (NDL 20-yr vs labor-only 10-yr vs full-system 30-yr) so the bid math reflects the fastener pattern and inspection cadence the warranty actually requires.

PAIN · WHAT THIS REPLACES

Where the hours actually go today

  • Roof area priced off floor footprint, pitch correction skipped — a 6/12 roof comes in 12% short before fasteners are even counted.
  • Perimeter LF (ridge, hip, valley, eave, rake) rolled into a single "trim" line at field-shingle labor rate; the trim crew is 2-3x the field rate.
  • Tapered insulation missed entirely — the most expensive single line on most low-slope reroofs.
  • Warranty class assumed standard when the spec calls for NDL or full-system; the fastener pattern and the per-ply inspection sequence price differently.
  • Penetration flashing counted by area instead of by EA; mechanical curbs and skylights need their flashing kit priced per manufacturer detail.
LIMITS · WHAT BUILDBID IS NOT YET

Honest gaps — read before you buy

  • Manufacturer-specific warranty fastener patterns: BuildBid extracts the warranty class from the spec but does not validate the exact fastener spacing against a specific manufacturer's technical data sheet — reviewer must confirm.
  • Single-ply membrane seam welding inspection cadence: not in the takeoff (this is a means-and-methods item priced by the installer).
  • Photovoltaic / green roof / vegetative assemblies: out of scope for the Division 07 baseline — priced as a separate trade package with its own structural and waterproofing review.
  • Roof restoration / re-cover scopes (over existing): the takeoff is condition-survey-based, not drawing-based; supported only for tear-off-to-deck reroofs in the current flow.
REVIEW FOCUS · WHAT TO CHECK4 AREAS
CHECK 01

Plane-by-plane SF view: each roof plane broken out with pitch correction applied, squares totaled by assembly type.

CHECK 02

Perimeter LF schedule — ridge / hip / valley / eave / rake / step / counter-flashing tabulated by profile and gauge with sheet references.

CHECK 03

Drainage + penetration count — primary drains, overflow drains, scuppers, mechanical curbs, plumbing vents tied to roof plan locations.

CHECK 04

Tapered insulation slope diagram — average thickness computed per slope arrow, ISO board count broken out by thickness.

NEXT · TRY ON A SAMPLE

Sample plans, zero setup. The draft comes back with quantities, confidence flags, and the source rows we used. You review before you send.

Try on a sample roof package