This is a post-weatherization photo of how a contractor in a local low income weatherization program boxed a bathroom fan. That's the fan buried in cellulose with a piece of tin laying loose on top of it. The fan is in complete contact with the insulation which, in my opinion, could lead to a fire and there certainly is no air sealing going on. Seriously shameful.

Tags: attic, bad, boxing, fan, income, low, program, tin, weatherization, work

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If it's just a bath fan, what's the fire risk? Do the manufacturer's instructions call for clearance to combustibles?

I'm with David in that question. Not sure it's a fire risk, but it is a leaky component adjacent to a high humidity source. Does not look air sealed.

Addressing this as you would a can light before adding cellulose is how I've addressed this (box, 2 part all seams)

I think some may simply seal penetrations and seams in the box, which might be acceptable and does not appear to have been done either.

Wonder what local requirements are or how others handle this.

Ted, I was taught to box with 5/8" fire-rated drywall with a 3" clearance from any heat source. Once the box is fit into place it is foamed around the base. I tape my seams inside and out with approved foil tape. Some of the programs feel drywall is a mold risk, so they require boxing in metal stove pipe with a cap.

That looks like a regular bath vent not one of those heat lamp / vent combos.

If you have a heat lamp combo in there that might be a good precaution (check with the manufacturer) but for the rest there is not enough heat generated to cause an issue.

The big issue are recessed lights where you have a regular or CFL bulb pushing out 200+ degree heat inside the fixture itself

I will use a combination of tape, caulk & even foam around the outside of it - I never really touch the inside as that can screw with the UL labeling & besides that they are nearly impossible to get them clean enough for anything to stick long term

I tape the joints in the box with foil tape before I install the fan, then go in the attic after the drywall is in and foam the fan/drywall joint after the duct is attached and taped. I don't know how worthwhile it is, since a lot of air leakage tends to be inside the duct, in either/both directions, but if I can seal something, I do it.



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