- Decking
- The plywood or OSB layer your roof system is attached to, sitting on top of the rafters.
- Drip edge
- Metal trim along the roof edge that directs water into the gutter, not behind the fascia.
- Eave
- The lower edge of a sloped roof that overhangs the wall.
- Fascia
- Vertical trim board at the eave that the gutter attaches to.
- Flashing
- Metal pieces that seal transitions between the roof and walls, chimneys, or skylights.
- Gable
- The triangular wall section at the end of a pitched roof.
- Hip
- The external angle where two roof slopes meet — the opposite of a valley.
- Ice & water shield
- Self-adhered membrane installed at vulnerable areas — eaves, valleys, around penetrations.
- Parapet
- A low wall around the edge of a flat roof — common on pueblo-style architecture.
- Penetration
- Anything punching through the roof — vent stacks, skylights, HVAC curbs, solar mounts.
- Pitch
- How steep the roof is, measured as rise over 12 inches run (e.g. 4/12).
- Pitch pocket
- A small metal box filled with sealant around an oddly-shaped penetration.
- Ponding water
- Standing water on a flat roof more than 48 hours after rain. Bad sign.
- Rafter
- Structural framing member that runs from the ridge to the eave.
- Ridge
- The horizontal line at the top where two roof slopes meet.
- Scupper
- An opening in a parapet wall that lets water drain off a flat roof.
- Soffit
- The underside of the eave overhang — usually vented for attic intake air.
- Square (roofing)
- 100 square feet of roof area — the unit estimators measure and price in.
- Tear-off
- Removing the existing roof down to the deck before installing the new system.
- Underlayment
- The waterproof layer between the deck and the visible roofing material.
- Valley
- The internal angle where two roof slopes meet. Water concentrates here.