Garage Insulation

5/4/2021 at 10:09:26 PM

Do you have the house over top? or a roof?..Is it completely isolated from house or partially connected? If it has a actual roof and is connected to the house partially or fully, you have a unfinished garage roof, it should have a vapor barrier between the drywall ceiling and the rafters then "insulated fully" to at least 8-10" and also vent stops at eaves so the roof breathes. A roof must have venting and be insulated to be cool in summer and warm in winter, basic construction and there will be some effect even if walls not insulated. If it has house over top then insulate it with batt insulation fully as you will have noticed floor above is freezing every winter. If it is totally separate from house you could leave it but will have to do it if you insulate walls otherwise the builder did not finish the job. If no vapor barrier then I recommend tearing drywall all down and doing properly.

5/5/2021 at 10:56:52 AM

you haven't said whether you're heating the garage. If it's unheated you wont have any measurable energy savings by insulating the ceiling (assuming it's a roof space above and not a drop ceiling with living space above).

Note that starting with the 2006 Code it became required to apply a drywall finish to ceilings and walls. you may want to insulate and finish your exterior wall(s). This is for a small measure of fire safety as regular drywall will provide approximately 10 minutes of fire resistance.

5/5/2021 at 11:45:36 PM

We have no intention to heat the garage.

It is a roof above.

Because it is attached to the house on one side, we were wondering about energy savings inside the house if we insulate the ceiling.

From what I understand of your answer there will not be measurable savings.