My apologies in advance if the title is the incorrect terminology. Any-who my oldest daughters bedroom is directly above the garage, its cold! Sometimes very cold and I understand it probably will never be like some of the other rooms that aren't over the garage. However I wanted to take a stab at improving it a bit so I pulled back the drywall on the ceiling at the front of the garage in an attempt to block off or seals the rim joists. Initially I thought her bedroom ended right around where the garage doors are located. However I quickly learned that her room actually extends out past the garage doors about a good 18" 24" so my rim seal idea became pointless. In fact her bedroom HVAC vent is actually going outside past the garage doors and then up into her flooring. There is existing two sided faced fiberglass insulation laying between the joists. So back to square 1 and seeking advice on the best and perhaps a cost effective way to stop that air flow and block that off. I have on hand about four 2" foam boards my brother in law gave me. One of my ideas was to rip down those foam boards to fit in between the floor joists flush with the bottom of her bedroom flooring and spray foaming around the edges to seal it in. Would that be a decent solution? If I added some insulation as well below the foam board would that cause some type of moisture issue? My other more expensive idea but might be easiest and most efficient was buying a spray foam kit and just spraying the bottom of the floors to break that barrier. Thanks in advance for your time and help!
Can you get any more pictures? I'm curious where her room extends over the garage if it's just covered with soffit or ? I'm leary on DIY spray foam, I've read some nightmare stories on pro's not getting it mixed right and it needing removed. If I was to use foam board and fiberglass, I think I would do fiberglass first, than the foam board and than seal around the foam board with a caulk to stop any penetration, That would stop any condensation issues I believe.
You can see the end of her room in this pic That's a very good idea and makes a ton of sense. A bit out of my league of know how and while it wouldn't be a terrible place to have it if got moved into the interior part of the room it would be more in the way of where you walk a bit. Room would have to be re-arranged a bit for sure as currently its close to the wall.
I see the "soffit" is vented...where does that joist bay go (the other end) anywhere that it needs to be vented?
If it doesn't really need to be vented then blocking that vent off would help...then getting that 2" foam board up against the bottom of the BR floor would help a lot I'd think...seal it in with spray foam as you said...
Thanks brenndatomu ! So the other end of that joist bay go back towards into my garage and into my house. I'd assume it would hit another cross beam at some point. The complete Opposite end of it would be the back of my house, there is no soffit over hang out back there. Sorry hope that makes sense, I probably butchered explaining it. Sounds like a plan, thanks again!
Assuming that I understand your situation correctly, this could be a way to insulate the apartment overhang and limit air infiltration into the garage. This will also maintain a modicum of air circulation above the soffit. Caulk or spray foam as needed. Just a thought!
This is exactly what I looking or thinking of doing! My next question to the forum was should the foam board go first below the bedroom flooring OR should I put the fiberglass insulation 1st and foam board below? I am thinking the foam board 1st and fiberglass or roxul insulation below that would be easiest BUT easy isn't always right. I think either or would work but what the hec do I know
Probably either would work. You can only split hairs so fine. My thoughts on doing it this way is that you maintain a vapor barrier to the outside air, give support for the fiberglass insulation to keep it from drooping into the ventilated soffit and provide a ridged seal to stop air sneaking into the garage joists. Theory does not always work out exactly in practice. I would think that anything you do would be an improvement!
I still can't figure out why it's vented in the first place? Maybe ironpony can shed some light on it...
I can't really see why either. I have an identical situation where my second story overlaps my garage. When I built it I just stuffed the whole overhang with insulation to prevent air migration as well as insulate. 38 years ago and on the weather side of the house. No problems (that I know of). I guess ReelFaster could also lay the 2" ridged flat on the vent and stuff the whole overhang as well. I just thought he was concerned about venting.
ReelFaster If this helps, just remember the reason for vented soffit, is so that you can have an air chase to go up to a ridge vent. Some builders are just lazy and they finish it so it all looks the same without really understanding the insulation envelope
Thanks gang I really appreciate all your input and advice!! I understand the basic principles and am no expert but I am not sure why its vented either. And a little shocked that the room even extends out over the front of the home like that (even though you cannot tell it by the photo) and then the soffit is vented, makes little sense (again am not an expert or builder). It was stuffed with insulation anyways, so why not seal it off! Also shocked that the hvac vent goes out into the soffit as well. With soffit vented like that I wonder how warm the air coming out of her vent even is. This room is doomed to be cold! I took an outside pic to give a better idea.
This is the tie of year for builder shows around here; maybe in NJ also. Point I'm trying to make is seek out a spray foam installer/company and have them spray some closed cell into all of those joist spaces that are cantilevered out past the garage door wall. As far as the vented soffit goes for that area, maybe the builders just wanted to keep things consistent. I see the eave is also vented soffit but again, don't see where that air is vented out for circulation. Keep the heat register where it is, no need to move it. Also, unless your garage is heated and/or the entire joist space is insulated, (the one with the supply air) it is losing heat all the while the air moves through over the garage space. Your daughter's room will get the air, just won't be as warm as it should be. And by heated garage, I mean house temperature. There would be a lot of heat loss through that supply air duct to your daughter's room otherwise.
ReelFaster just so you know cantilevering over a stud wall is common building practice. A lot of raised ranches built that way.
I cannot stress enough the closed cell spray foam. We had it done to a crawl space here last summer and the difference has been unreal! It's your home, invest in it; I'm confident you'll have no regrets. And don't forget to check out that heat run insulation across the garage ceiling thing..... And please let us know what you end up doing.
Thanks yooperdave !! Taking baby steps right now. Being the garage is not heated I know and tried to explain to my wife a real fix would be pulling down the sheetrock ceiling in the garage and re-insulating it or better yet spray foaming it to really correct the issue. But that's a huge job and a expensive one right now and we are always on the fence if we are staying here or moving. I first want to tackle this vented soffit as that is just flat bothering me and flat out cold air almost directly against the front part of her bedroom flooring. The HVAC run also concerns me traveling across a good portion of the garage, lots of heat loss as you mention. I'd like to at least address that as well and only thing I can think of is spray foaming it, not enough room to really add much insulation as the duct takes up almost the whole joist bay. Other joist bays do have insulation in them, surely not enough or not doing much but at least something is there.
