What the written scope should name
Expect line items for wall-top-to-ceiling joints; gaps around wiring, plumbing and bath-fan housings; duct boots; open chases and dropped ceilings; and the attic hatch or pull-down stairs. Larger openings need a rigid cover with sealed edges—OSB, drywall or rigid foam—not more insulation pushed into the void (PNNL ceilings guide). Ask whether moving and restoring existing insulation is included, and keep added insulation as its own priced item so you can compare bids. For depth after sealing, see how to tell if attic insulation is enough for winter.
Stop-work conditions come first
Before sealing, the assessor should check for roof leaks, moisture damage, unsafe wiring and exhaust fans that dump into the attic (pre-retrofit attic assessment). Active knob-and-tube wiring and vermiculite insulation are stop-work items in federal retrofit guidance. Suspected vermiculite should stay undisturbed; EPA treats it as potentially asbestos-contaminated and calls for an asbestos professional before any work that would disturb it (EPA vermiculite page). From living space you can note ceiling stains, drafty hatch edges, and where lights and bath fans sit—then ask for attic photos instead of moving insulation yourself.
Recessed lights need a fixture plan
Have the contractor read each recessed fixture’s rating. IC means insulation contact; AT means airtight. A can can leak air without being safe to bury in insulation. For non-IC fixtures, PNNL describes a protective enclosure with a 1-hour fire rating and at least 3 inches of clearance on all sides, or replacement with an ICAT fixture (non-ICAT recessed lights guide). The scope should forbid foam or sealant on the non-IC can and should not plug its heat-release openings from below. An electrician should confirm older wiring and whether replacement is safer than boxing.
Chimneys and flues are not ordinary gaps
Seal around the chimney or flue chase at the ceiling—not inside the exhaust path. Guidance calls for heat-resistant barriers such as sheet metal and high-temperature sealant, plus clearances to combustibles (duct and flue shaft guide). A promise to “foam every hole” is not enough. Ask for a vent-specific detail and have a chimney or HVAC pro verify it for the appliance you have. After sealing, combustion safety still matters; see how to check for flue backdrafting.
Keep attic vents open and the hatch usable
In a vented attic the goal is a tighter ceiling, not blocked soffit or ridge vents. The scope should preserve baffles where fibrous insulation would smother soffit intake (PNNL ceilings guide). Bath fans must discharge outdoors—rerouting is corrective work before sealing. The hatch or pull-down stair needs a continuous gasket and a cover that still opens; insulation on the panel is separate from the air seal (attic access guide). For moisture that looks like a ventilation problem, see attic ventilation vs roof moisture.
Local path in Philadelphia, then verification
PECO electric customers can schedule a Home Energy Assessment for $49 (market value listed at $199 on PECO’s May 2026 flyer) that looks for air leaks and insulation gaps and may install free energy-saving products valued up to $125 (PECO Energy Assessment flyer). Ask the assessor how attic air sealing shows up in the report. Separately, Philadelphia’s Weatherization Assistance Program through PHDC lists “insulating and air-sealing of the roof area” among measures for income-eligible city properties after a free audit; intake is 215-448-2130 (PHDC Weatherization). A broader take on assessments is in whether a home energy assessment is worth doing.
Ask how work will be verified: before-and-after blower-door numbers where testing is safe, photos before insulation hides seals, who checks whole-house ventilation needs, and who runs post-work combustion-safety tests when natural-draft equipment is present. Finally, list what is included, separately priced or excluded—roof repairs, asbestos handling, electrical replacements, exhaust rerouting, duct sealing and extra insulation—so competing scopes are comparable.