Safety around exposed fiberglass insulation? Appropriate way to finish a space?

[FLBiker]

Above our garage is a large space that isn't insulated.  It's partially floored, and the roof of the garage (the floor of this space) is insulated with fiberglass.

My first question is -- given that some of the insulation (in the floor of this space) is exposed, would it be unsafe to spend extended time in this space?  I'm asking because I was thinking of using it for a meditation retreat, thus I'd be in it for 20+ hours a day, for 5 or 6 days.  There isn't a lot of wind or vents to cause disturbance, but there are soffit vents and a couple of windows that I would probably have cracked open.  Would this be unsafe?  (My alternative would be to get an AirBNB for ~$400 CAD).

If it would be unsafe, what would be the easiest way to make it safe?  If I hung panel board to make knee walls, would that work?  There would still be gaps between the studs at the top of the panel board.  Alternatively, would it be better to staple 4mil plastic on the back of the insulation?  I've read mixed things about this in terms of condensation.

At this point, I'm only concerned about air quality.  Ultimately, we'd probably like to insulate the space and finish it a bit more, although we may not worry about making it a four season space (we're in Canada and the garage is currently unheated). 

I've attached a picture that shows the space.  The unfloored section with exposed insulation is on the left, the area I'd be in is on the right.  If additional pictures would be helpful, or if you have any questions, please let me know.  Thank you for your help!

[SunnyDays]

If there isn’t a lot of insulated space, you could replace the fibreglass with a mineral wool, like Roxul or even put it on top.  It’s a lot less irritating and as long as there’s not a lot of air movement in the area, it shouldn’t blow fibres around.  You could also hang plastic vertically in front of the insulated space regardless of which insulation you use.  That will allow more air space, so less of an issue with condensation.  Another option would be to use fabric instead of plastic, which would reduce condensation even more.

[nereo]

There’s not much risk to air quality from fiberglass batts unless you are actively cutting and moving them.

The bigger risk is fire. You didn’t specify what the ceiling of the garage is, but code requires a fire barrier between any occupied spaces and the garage (drywall, roxul, or self-extinguishing tuff-r are all options). If it’s faced the batts can burn, and cars are a great ignition source (often aided by the plethora of flammable materials we tend to store there, like gasoline cans and lubricants). In a fire batts give off an acrid, horrible smoke that will choke you.

I wouldn’t worry about air quality from the fiberglass lying between the joists. I would careful consider fire danger, barriers and exits.

[lthenderson]

Undisturbed, insulation isn't a health risk.  But if I was going to spend time up there with a breeze blowing through (and possibly disturbing fiberglass particles), I would make an effort to seal it. I would NOT use plastic. Plastic isn't permeable and could create condensation or moisture issues causing mold, etc. if not properly thought out and done. Without knowing how your garage is attached to the house, HVAC or built, I would recommend going with something permeable that lets moisture through but not the fiberglass particles and use that to seal up the knee walls.

[FLBiker]

The bigger risk is fire. You didn’t specify what the ceiling of the garage is, but code requires a fire barrier between any occupied spaces and the garage (drywall, roxul, or self-extinguishing tuff-r are all options). If it’s faced the batts can burn, and cars are a great ignition source (often aided by the plethora of flammable materials we tend to store there, like gasoline cans and lubricants). In a fire batts give off an acrid, horrible smoke that will choke you.

The ceiling of the garage is foam board insulation, on top of OSB (I think).  And, you're right, that the exit isn't great (a pull down ladder to the garage) but there are egress windows, one of which goes out to the roof of the mudroom.  Plus, our plan is to keep the car outside of the garage whenever we'd use this space (for fumes and noise) which would also reduce the fire risk.  One thing that isn't in that space (that we'll certainly need to add if we're spending time there) is a smoke alarm.  Thanks for raising this issue.

Undisturbed, insulation isn't a health risk.  But if I was going to spend time up there with a breeze blowing through (and possibly disturbing fiberglass particles), I would make an effort to seal it. I would NOT use plastic. Plastic isn't permeable and could create condensation or moisture issues causing mold, etc. if not properly thought out and done. Without knowing how your garage is attached to the house, HVAC or built, I would recommend going with something permeable that lets moisture through but not the fiberglass particles and use that to seal up the knee walls.

That makes sense -- the garage is connected to the house via a small mudroom.  Both the garage and the mudroom were added after, so the connection between the mudroom and the house was originally an exterior wall.  We heat the house, but basically leave the mudroom unheated (there's an electric baseboard heater that we have set at 5C) and we don't heat the garage.  There's no AC / air exchanger in either space.  In our house we have both an air exchanger and a minisplit upstairs.

You could also hang plastic vertically in front of the insulated space regardless of which insulation you use.  That will allow more air space, so less of an issue with condensation.  Another option would be to use fabric instead of plastic, which would reduce condensation even more.

I like both of these ideas.  Thanks!