Insulation above bathroom vent

[thatguy]

We got a very light snow a while back and I noticed there was a 18"x 18" spot on our hip roof that was not snow covered.. From the attic I can see that the spot is right above a halfbath exhaust vent/light and there was no insulation covering the vent ..

Should there be insulation covering this vent?

Brian

 

[jeffah]

Is this a fan/light combination?

Most of these fixtures are rated for contact with insulation.
You will want to make sure it is before you cover it.

Does the vent go outside or just dump into the attic?

 

[Mounted Madness]

There was a repair clip on "This Old House" last fall. Here's a link for you to take a look at. I think it'll answer most of your questions/concerns. :thumbsup:

Ventilation | How-to | This Old House

 

[bdeboer]

I have made a box out of 2" Dow Score board over them. I used an ahesive for foam insulation to hold it in place.

If it comes in contact with the fan make sure it is rated for "Insulation Contact".

 

[Craig Clayton]

Make sure you exhaust fans vents out properly or you will have MAJOR problems in your attic. I strongly agree with take your info from This Old House.
Craig Clayton

 

[thatguy]

Thanks.. it is a light/fan combo and is vented to the outside - Ill see if I can dig up the owners manual and see if it is rated for insulation contact

brian

 

[rus_geek]

Another question, was the fan intentionally not covered with insulation, or is it leaking and blowing the insulation away from itself? (Assuming loose cellulose or fiberglass, not bats). As others have mentioned, if it is IC, bury it, otherwise build a box around it and bury that instead.

-rus-

 

[SARG]

Last summer I noted our roof sheathing i.e. plywood was turning up at the edges creating humps that were lifting the shingles. Found out that the vent stack pipe had an opening that was allowing moisture from the home to enter the attic space.

Had to replace three sheets of plywood and the shingles...... after replacing the vent stack.

 

[CompactTractorFan]

Our vent is vented to the attic...:confused2:

 

[jeffah]

If the unit is a Nutone Broan 744 - which is the typical builder grade unit for this application(at least for the houses I work in). Then it is approved for contact with insulation. But a foam box as mentioned earlier adds insulation as well as prevents air leaks. A foam box sealed to the drywall with loose fill insulation on top would be your best DIY combination.

If you build a foam box make sure you use a glue or caulk that will not "eat" the foam like most generic construction adhesive will.

 

[Craig Clayton]

To compactTractor fan
When you say that your fan is vented to the attic I hope you mean that it is vented to the outside. I know of bad mold damage when the exhaust went into the attic space in northern clims.
Craig Clayton

 

[SARG]

Our vent is vented to the attic...:confused2:

Which is essentially what caused our roof sheathing to cup & rot.

 

[bironacad]

Our vent is vented to the attic...:confused2:

I have 16"-18" (R60) over my vent piping in the attic which lead to the outside, lol. Venting bathroom vapor to the attic here would condensate and drip through the drywall in no time. More moderate climates would, I think, still acquire black mold and wood rot in a short time. Moisture vapor in an attic space can be very bad hence the need to vent to the outside.

In reference to the original post which has been addressed already there could be heat challenges if the unit is not rated for direct insulation, pot lights for example when placed in enclosures require (here) thermal protection fuses to prevent fire and an adequate space to combustibles this information is included in the packaging. If you know the make and model you can usually get specifications from a manufacturers site.

Get r done

 

[johnrex62]

I have 16"-18" (R60) over my vent piping in the attic which lead to the outside, lol. Venting bathroom vapor to the attic here would condensate and drip through the drywall in no time. More moderate climates would, I think, still acquire black mold and wood rot in a short time. Moisture vapor in an attic space can be very bad hence the need to vent to the outside.

Wow. This really points out the differences climate can make. You have more insulation over your pipes than we have in the entire state of Texas. :laughing:

I grew up in a house in south Texas that had 2 inches of rock wool insulation. The bathroom ventilator exhausted into the attic space. No other ducting or venting. We had a single bathroom for the whole family and with two girls it saw a lot of use. Never any mold or mildew in 40 years. The attic itself was vented with a 20' gable vent at each end of the house and a couple air motors (whirly bird vents) on the roof.

The idea was as long as the attic air changed regularly it would stay dry. I guess it worked well. The house had a dry, dusty attic for over 60 years.

Youse guys up nawth have a very different set of rules to live by and this thread sure makes me glad I can't use snow to find hotspots on my roof. :thumbsup: