Insulated Garage Doors

[Handyandy23]

We're having a new home built and it has come time for me to select my garage doors. The vendor has a few options on insulation R-values and windows, and I'm looking for help / opinions on what to go with.

Their "basic" door has an R-9 insulation value and comes with single-pane glass. There are upgrade options to go to R-12 or R-16 rated doors, or double-pane glass.

The garage will be heated, and it is in a cold climate (near Detroit). For reference, the garage walls are spec'ed out at R-22 insulation.

Is this just a case of "more is better" and go with the highest R-value I can get (which is closest to the walls)? Or is the difference between R-9 and R-16 somewhat minimal? My current garage has an insulated door (of what R-value I can't remember) and single pane windows, and I have no issues keeping it warm, although it is coldest near the doors of course.

What are other GJers doing in the northern climates?

 

[ItsNemo]

Well it really depends on cost. When I did my new house, I went from a 16x7 uninsulated door with no windows to a 16x8 R12 insulated door with a row of double pane windows for only $500 which for a builder supplied upgrade felt very reasonable.

I find the R12 door is sufficient, even unheated the garage stays above freezing all winter (R14 in the outside walls, R22 in the adjoining walls, R32 in the ceiling). It's more about the sealing around the door and you reach a diminishing ROI on the door itself at some point.

 

[Handyandy23]

Yeah I was kind of hesitant to mention cost because I'm sure the "worth" of the upgrade is different for everyone depending on budget. But for a 16x8 door the upgrade to R12 is about $450, or R16 for $700. The R16 also comes with an upgraded weatherstrip around the outside, which I could add to the R12 for about $50 (making it $500). The double pane window is about $150 more than the single pane.

I'm thinking for the relatively minimal upgrade cost it's worth it to go R16, but you can also jack up the price of the house quite a bit using that attitude everywhere.

 

[ItsNemo]

If you are going to heat it 24/7 I'd agree at that price. If you're going to just heat when you're in there once or twice a week, the ROI isn't there assuming natural gas and a 20 year door lifespan.

 

[Redraptor]

Or is the difference between R-9 and R-16 somewhat minimal? My current garage has an insulated door (of what R-value I can't remember) and single pane windows, and I have no issues keeping it warm, although it is coldest near the doors of course.

What are other GJers doing in the northern climates?

I have 2 "insulated" ribbed steel doors in my shop. I think they are R-9. The problem with mine is they sweat in extreme weather even though the inside temp is 55. The steel from the edges of the panels transfers the cold. I don't particularly feel the cold but I see it.
I suggest flat panel doors with a thermo-break in whatever R value they offer.

 

[jonshonda]

If you are going to heat it I would get the best doors your can afford as well as door seals.

 

[patterg2003]

You are leaning in the right direction and it is a place where the money in will come back several times over the life of the door. A higher R value will pay back with heat savings. It will also make it better if you have living spaces over the garage. The minimum window would be a double pane. Easy payback on the dbl pane. The single pane will frost up and has no insulation value. The quality of the door seals are important as well because if there is serious air leakage then it defeats the benefits of a well insulated structure. We just moved into an older house before Christmas and when it was 40C below the heat system barely maintained temperature. I waited for a warmer day and replaced the door seals on the front & back doors. The difference was immediate. There is a way of calculating the btuh differences and calculating the difference in gas costs to see the paybacks. This house has old windows that are dbl pane sealed units and a person can feel the cold radiating in. We bought this house low as it is structurally sound but was owned by an old couple that maintained it but it is due for a makeover. I am measuring up for new windows that will be triple pane low e. Not sure if double low e is worth it. I put all triple pane low e windows in the house we left and the gas bills took a good drop. A person can stand very close to the triple pane low e windows and feel no cold until they touch the glass. There is a point where there is no return on going excessive on the insulation but this would not be one.
Glenn