[ront02769]

Trying to play catch-up on a neighbor's project that got ahead of itself and he is now looking for ideas. Scenario: detached three car garage with huge space overhead that was to be storage. Decided that a sleeping area might be nice instead and insulated ceiling of first floor and hung and taped requisite fire code drywall. There are still ten boxes in the ceiling with duplex outlets that will have fluorescents plugged into them. Issue the boxes are just the blue plastic deals, romex coming in, not sealed against either air infiltration, fire, or possible carbon monoxide. Easy to seal around the outsides with can spray foam. Question as to how to insulate the holes that the wires come through (building inspector wants this done....but is not telling him how). My thought was to have him unscrew the outlets, unfold the wires letting them hang down, and then just foam the holes. He would rather just turn off the power, stick the tube of the spray foam in the box, and fill er up. Thoughts?? Ron

 

[Jim Port]

Spray foam cannot be used inside the box.

 

[Bud9051]

I agree with Jim about not filling the boxes with foam. Not sure what the inspector would say, but fairly sure electrical code would not approve. In addition, any foam sealing is not permanent and blocking CO must be, regardless of what the inspector will allow. Studies have shown can or spray foam to crack and/or release over time. No articles to cite at my fingertips, but they are out there.

A bedroom over a garage is scary and doubtful all current efforts will totally seal the air leakage. Any sealing should use a fire rated caulk. Ask the inspector if a small enclosure fabricated out of drywall and glued together with FR caulking would be acceptable. Also, consider having the building pressure tested for air leakage.

Also, were the rafters insulated and how and were they ventilated?

Bud

 

[ront02769]

Question on no foam, for other penetrations such as garage door hangers, foam is the deal of choice? Plus I volunteer at a whiskey distilling place that recently did a new back room and for their commercial rating they had to use the orange foam around every penetration. But that was in Ri. Ron

 

[Jim Port]

The orange is fire rated foam. It cannot be used in the electrical boxes either. It can be used to seal around penetrations.

 

[ront02769]

I agree with Jim about not filling the boxes with foam. Not sure what the inspector would say, but fairly sure electrical code would not approve. In addition, any foam sealing is not permanent and blocking CO must be, regardless of what the inspector will allow. Studies have shown can or spray foam to crack and/or release over time. No articles to cite at my fingertips, but they are out there.

A bedroom over a garage is scary and doubtful all current efforts will totally seal the air leakage. Any sealing should use a fire rated caulk. Ask the inspector if a small enclosure fabricated out of drywall and glued together with FR caulking would be acceptable. Also, consider having the building pressure tested for air leakage.

Also, were the rafters insulated and how and were they ventilated?

Bud

Ceiling rafters were insulated fiberglass, not sure how the guy did it. As to the box thing, the outlets must be available to plug the guys fluorescents into....plus as noted the ceiling is done, done and done.

Goes to show how the trades need to. Work together I guess. Habitat house I was at the electrician set his boxes, ran his wires and just left six inches with the outer casing removed coiled inside each box, outside walls, inside, didn't matter. Then the insulation crew came in and foamed the walls and used a screed gadget to remove excess as they went, mostly didn't fill the boxes but some more than others.then we installed and taped the drywall, painted, electric guy comes back and installs fixtures, outlets, etc. and puts insulated faceplates on them. Done...correct sequence....no going back to try to figure out how to retrofit something. Thanks. Ron

 

[MrElectricianTV]

Trying to play catch-up on a neighbor's project that got ahead of itself and he is now looking for ideas. Scenario: detached three car garage with huge space overhead that was to be storage. Decided that a sleeping area might be nice instead and insulated ceiling of first floor and hung and taped requisite fire code drywall. There are still ten boxes in the ceiling with duplex outlets that will have fluorescents plugged into them. Issue the boxes are just the blue plastic deals, romex coming in, not sealed against either air infiltration, fire, or possible carbon monoxide. Easy to seal around the outsides with can spray foam. Question as to how to insulate the holes that the wires come through (building inspector wants this done....but is not telling him how). My thought was to have him unscrew the outlets, unfold the wires letting them hang down, and then just foam the holes. He would rather just turn off the power, stick the tube of the spray foam in the box, and fill er up. Thoughts?? Ron

Try putty pads. I think 3M makes them.