What does skylight installation involve, and what drives the labor cost?
Short answer. Skylight installation is several trades in one job, roof cutting and flashing, framing, insulation and drywall, so the labor cost depends mostly on whether the unit fits between existing framing and how long the light shaft is. A unit that fits between rafters on a simple roof is a modest job, while one that requires cutting trusses, an engineer's plan and a long flared shaft costs several times as much.
The installation, step by step
- Layout. Find the framing from the attic, mark the opening, and plan the shaft so it clears ducts, wiring and plumbing vents.
- Roof cut. Remove shingles around the opening, cut the decking, and frame headers at the top and bottom.
- Mount and flash. Set the unit or curb, wrap it with underlayment, and install the manufacturer's flashing kit woven into the shingles.
- Ceiling cut and shaft. Cut the ceiling, frame and insulate the shaft, then hang, finish and paint drywall.
- Electrical, for powered or solar venting units with remotes and rain sensors.
- Inspection, if your city or county requires a permit for a new roof opening.
The truss question
Most newer Georgia homes have engineered roof trusses rather than rafters. Truss members should not be cut or removed without an engineered repair design, because each piece carries load. A skylight that fits between trusses avoids that entirely, which is why many standard skylight widths are made to fit between framing spaced 16 or 24 inches apart. Older homes with stick-framed rafters can often be framed with doubled rafters and headers.
What raises labor cost
- Steep or high roofs.
- Tall attics or vaulted ceilings with long shafts.
- Flared shafts, which spread light but take more framing and drywall.
- Ducts or wiring that need rerouting.
- Tile or metal roofing, which takes specialized flashing.
Doing the roof portion during a reroof cuts labor because the shingles are already off. See replacing skylights with the roof and roofing permits in Georgia.