Duplex With a Continuous Attic and a Tenant Who Will Not Leave
A 1972 side-by-side duplex, 1,100 ft2 per unit, shares a common foundation and a continuous, undivided attic. The owner of Unit A contracts for a sulfuryl fluoride fumigation for drywood termites. Unit B is occupied by a family with a 7-month-old and a parakeet, and the tenant has refused to move out for the day. The units are connected by an unsealed 18-inch attic pass and a shared water-heater closet with louvered doors; the water heater in A has a standing pilot. Unit A also has a 12 x 20 ft raised wood deck attached at grade, twelve recessed ceiling lights, a fireplace with a damper that will not close fully, and a whole-house fan. The crew plans to tarp Unit A only, sand-snake the tarp along the foundation, charge at 7 a.m., and pull the tarp by 3 p.m.
1. Do you proceed as planned? State the decision and the conditions that must be satisfied before any charge is released.
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Do not proceed. A tarp over Unit A does not create a separate airspace. With an undivided attic and a shared water-heater closet, A and B are one communicating volume; the fumigant will migrate into B and into an occupied bedroom with an infant.
Must be resolved before charging:
- Either vacate and include Unit B -- both units prepared, tarped, and cleared as a single structure -- or create and verify a gas-tight separation of the attic pass and the utility closet. In practice the second is rarely verifiable in a 1972 duplex, so the realistic answer is a whole-building fumigation with both tenants out.
- The tenant's refusal does not create an exception. Occupants must be out; if B cannot be vacated, the job is rescheduled or declined. A signed refusal from a tenant is not a legal shield.
- The infant, the bird, and any pets must be out of the entire affected volume -- birds are extremely sensitive to fumigants.
- Pilot lights and gas appliances addressed before charging.
- Notification and written acknowledgment from B's occupants at the interval required by the label and state rule, documented.
Escalate to the licensed operator and the owner in writing rather than deciding on the tailgate of the truck.
2. For each of the following -- attic pass, shared louvered water-heater closet with standing pilot, fireplace with a leaking damper, whole-house fan, twelve recessed lights, raised deck -- state the corrective action and why.
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| Item | Action | Reason |
|---|---|---|
| Attic pass / continuous attic | Eliminate the boundary (treat both units) or seal and prove it | A 18-inch open pass is a direct pathway; a tarp below it is irrelevant |
| Shared water-heater closet, louvered doors, standing pilot | Extinguish the pilot and shut the gas; seal louvers and the closet boundary, or include the space | Open flame plus a fuel-gas source inside the envelope; louvers leak both ways |
| Fireplace, damper not closing | Seal the firebox with taped plastic/cardboard and seal the chimney top | A chimney is a vertical flue to the outside -- the classic cause of a short half-loss time |
| Whole-house fan | Seal the blades and the ceiling opening | Direct, large-area path into the attic and out the roof |
| Twelve recessed lights | Tape/cover per label | Unsealed can lights are a known leak path into the attic |
| Raised deck at grade | Include the deck inside the envelope with a verified seal to grade, or treat the deck separately | A sand snake laid in front of the deck leaves the space beneath it open; fumigant escapes and deck galleries are never exposed |
Each item is a leak path, a fire/gas hazard, or an untreated infested wood member. Any one of them can defeat the charge on its own.
3. What notification and documentation obligations run to the occupants of Unit B, and whose license is on the line if the schedule is rushed?
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Notification: B's occupants are adjacent occupants of a structure that is functionally part of the fumigated volume, and once the job is restructured as a whole-building fumigation they are primary occupants. They must receive the written pre-fumigation notice at the interval the label and state regulation require, it must be posted at the unit, and their acknowledgment (or documented good-faith attempts plus a copy left at the door) belongs in the file. Verbal 'we'll be out' from a tenant is not documentation.
Disclosure content: what is being used, the entry prohibition, the expected vacate and return times, what they must remove (people, pets, plants, food, medications), and who to call.
License exposure: structural fumigation is performed under the Branch 3 (field representative/fumigation) license of the operator in charge. A migration into an occupied unit is a reportable exposure event and a licensing matter, not just a customer-service problem. The fumer in charge signs the fumigation record and owns the decision to proceed -- the account manager and the owner do not.
File contents: the notice, the acknowledgment, the prep checklist with each item signed off, the seal verification, and the clearance readings for both units.