Any way to insulate ceiling without taking sheetrock down?

[dvg]

Im trying to winterproof my garage a bit (Location : Sothern Ontario)

Background info is at the bottom.

I am wondering if it is possible to add insulation to the ceiling of my garage without taking the sheetrock down. Is there any way to just cut small holes in the ceiling and blow in some insulation?

Would roof ventilation be necessary? There are soffits right now but no vents on the top of the roof. Im not sure when vents are needed, when vapor barriers are needed, etc.

The garage is attached to the house and the majority of it is under living space. Its a 17 wide x 20 deep garage and about 16 feet of that depth is under living space, where there is sprayfoam insulation to keep the living space warm and act as a vapor barrier. The 4 feet that extends from the front of the house has no insulation - see picture.

The walls have batt insulation on all sides. I have filled in the garage door panels with R4 styrofoam (By the way, should I increase the garage door spring tension to account for the increased weight). I am installing green hinges to prevent drafts on windy days.

 

[dvg]

I should mention , I dont plan on heating 24/7. Really just when I want to work in the garage, but I do want it to maintain a higher temperature if possible at all times.

 

[NUTTSGT]

I'd make sure maintain the proper ventilation to prevent issues farther down the road.

You can cut holes or use a hole saw, might be neater and easer to patch and blow some insulation in.

If you raise the door half way up, will it stay where you put it or does is slowly creep back down ? If it creeps down, I would increase the tension slightly and recheck.

 

[NUTTSGT]

I should mention , I dont plan on heating 24/7. Really just when I want to work in the garage, but I do want it to maintain a higher temperature if possible at all times.

You may not heat it all the time but it'll also keep the house slightly warmer too. Think of it this way, during the Winter, 3 sides of the house have low temps hitting them. The fourth side, where the garage is at, is warmer because you're heating it and it's helping maintain the temp.

In the middle of winter, go outside via the garage rather than the back/front door. Would you rather have air temps of teens (outside air) rushing in the house or warmer (30-40 degrees) air from the garage coming in the house ? It's like an airlock or vestibule of a commercial business.

 

[dvg]

I dont know much about insulation/ventilation... I get the impression that roof venting is not necessary without insulation, but is necessary with insulation. Is that correct? If so, what is the reason? There is no roof ventilation right now but there are soffits as mentioned. The house was built last year so adheres to the latest building requirements in my area.

 

[Electric]

I am also in southern Ontario, doing much the same work. I am pulling down all the sheetrock on the ceiling, because I need (at least, I think I need) to install a plastic vapour barrier between the sheetrock and the underside of the joists.

The alternative would be to spray in 1-2" of high pressure foam on the top side of the existing sheetrock, which would provide a vapour barrier. Then I would blow cellulose insulation on top of that to achieve R30-35. I ruled out this option, because I was looking at $1000 to spray in the foam, and I can re/re the sheetrock for much less than that.

So the plan right now is:

1. remove sheetrock from ceiling
2. staple vapour barrier to underside of joints and seal edges with that red seal tape
3. reinstall sheetrock
4. install styrofoam containment barriers to prevent cellulose from covering vent perforations in the soffits
5. blow in R30-35 of cellulose

Hope this helps.

 

[dvg]

I had an insulation contractor in to take a look and they actually recommended I do nothing in my situation and use case, since it is only a small portion of the ceiling that is uninsulated, considering the cost and the limited usage it wouldnt make sense.

 

[NUTTSGT]

I dont know much about insulation/ventilation... I get the impression that roof venting is not necessary without insulation, but is necessary with insulation. Is that correct? If so, what is the reason? There is no roof ventilation right now but there are soffits as mentioned. The house was built last year so adheres to the latest building requirements in my area.

You need to have some ventilation. Ever seen a house get new shinlges and a few years later, the shingles start curling up and look like **** ? More than likely, it's due to poor ventilation in the attic.

I had an insulation contractor in to take a look and they actually recommended I do nothing in my situation and use case, since it is only a small portion of the ceiling that is uninsulated, considering the cost and the limited usage it wouldnt make sense.

That guy isn't paying your heating bill either.