Garage Ceiling Insulation

[wjh0919]

My garage is 24 x 24 with a double garage door - ok size for me. The house was built in the early 80s and the exterior walls are brick veneer. I assume the walls are insulated however I have not confirmed that.

The attic over the garage is not insulated and there is tongue and groove subflooring on the attic floor. I do not use the attic for storage and I'm positive I will never use it for storage. There is a pull down staircase for access if necessary.

I want to insulate the attic so I can get some use of the garage in the winter time - however I'm not sure the best way to insulate. Should I remove the decking from the attic floor and insulate? Should I blow in insulation? Is it ok to roll out insulation over the top of the decking?

I don't necessarily want to remove the decking - but will if necessary.

thanks for the suggestions....

 

[Scott H in Wheaton]

You can do what is called "closed cavity" insulation...they drill a hole in one end of the attic floor and insert a hose to fill the cavity. Stick in a plug and move to the next joist and repeat. It can be filled with either fiberglass or cellulose.
Your floor is still usable.

 

[matt_i]

Does the subfloor extend thru the entire attic out to the acute angles in the trusses or rafters, or is there a gap (like as in an attic storage truss)?

If there was a gap or you could rip about a foot out of the T+G with a circular saw set to just cut thru the decking, then I think you could stuff loose fill cellulose in there by hand. Sort of tedious but it can handle the packing and not lose a lot of R-value like fiberglass.

 

[NUTTSGT]

I'm guessing there is a ceiling in the garage so you can't just add batts ?

 

[wjh0919]

T&G decking on the attic floor covers the entire area - wall to wall. No way to cut near the edge - however removing parts in the center is an option.

 

[OccupantRJ]

Why not blow in insulation right on top of the flooring? You said you were not going to use it anyway. The open area underneath the floor will become a dead air space relative to the room underneath.

 

[Todd.Brock]

I would cut a 12”x12” section, have it blown in under the floor and then blow over the floor. If you really needed the storage the floor would still be there at least. Just put the 12” plugs back in!

 

[stm317]

I would cut a 12”x12” section, have it blown in under the floor and then blow over the floor. If you really needed the storage the floor would still be there at least. Just put the 12” plugs back in!

Me too. That way, if you ever have to do work in the attic, you don't have to worry about falling through the ceiling below. And, a future owner might appreciate the attic storage option. Fill the empty cavities as much as possible, and then blow insulation on top of the T&G for the remainder.

 

[BillK]

You didnt say where you are located but my attached 22x22 does not have insulation in the ceiling. The ceiling is drywalled. The walls are insulated. I have a 5000 watt heater and it will get it comfortable fairly fast no matter what the temperature is outside. One key thing is a tight fitting garage door. That is probably more important than worrying about the attic.

 

[wjh0919]

Located southwest OH. Temperature in the garage this morning was 28 as I was going to work. Granted it was 7 outside - but 28 inside is not workable. Current garage door is junk -wood and heavy - and will be replaced with an insulated door this year.

 

[BillK]

Current garage door is junk -wood and heavy - and will be replaced with an insulated door this year.

Spend your money on that now instead of worrying about the attic. When I had the old wooden door there was no way I could heat my little space up. A salamander would do it but that was crazy. As soon as I replaced the door it was all the difference in the world. The insulation in the door helps for sure but the main thing is keeping the cold air out.

 

[Todd.Brock]

Hey- I’m in SW Ohio too- Cincinnati. If you want a nice garage door- CHeck out PDQ doors in Milford

 

[wjh0919]

thanks for the lead. I'm in Tipp City/Troy area. will check into PDQ Doors.

 

[lakeroadster]

Are there soffit vents? Is the tongue and groove notched to allow air flow from the soffit vents into the attic space?

Is there is a vapor barrier between the ceiling joists and the garage ceiling?

If the answer is no and you simply insulate on top of the existing flooring you may end up with condensation issues that could lead to mold in the void between the flooring and the garage ceiling, especially if the garage is heated (which it will be by default if you pull in a warm car in the winter.)

 

[Badasssapper67]

Since you have t&g through out, I'd insulate the roof itself. No sense making mold an issue. Lay on your back and staple it in. Keep the cold out of the whole shebang.
Not saying everyone should do that or it's the only right way just saying what I'd do.

 

[NUTTSGT]

T&G decking on the attic floor covers the entire area - wall to wall. No way to cut near the edge - however removing parts in the center is an option.

You missed what I was inquiring about.

The attic floor is T&G decking, that is on top of the truss bottom chord. Is there a ceiling on the bottom side of the trusses ?

If so, what is it ? If not, I'd just use fiberglass batts stapled in between the trusses.

 

[GMCGarage]

Might try USA insulation and do the foam ****. They seem to be advertising alot, so get a quote.

 

[Ak Jim]

If using spray foam use closed cell to prevent moisture problems.