Additional garage door insulation

[MountaineerTom]

My workshop has a basic metal insulated garage door that installed in 2007. It still has room to put some more insulation on the inside. I already have some Reflectix (looks the same on both sides, shiny and reflective) on the inside and it’s made a difference. I’m thinking of adding some 1/2” foam board with the silver reflective facing to fill in the space left.

How should I install this with what I already have?

-New 1/2” foam board between the foam that’s already on the door (reflective facing towards the garage door) and the Reflectix? Or the opposite, with the reflective facing towards the interior of the workshop?

-New 1/2” foam board with reflective facing towards the interior and the Reflectix between it and the foam already on the door?

-Or maybe just another layer of the Reflectix?

-Does it even matter?

I have the windows blacked out with 1/8” black ABS panels. I may spray some expanding foam into the frame channels as well.

 

[MountaineerTom]

I’m thinking foam board in the middle with reflective part facing the door/outside.

 

[KennethS]

I have just the foam board on mine. The doors are in full afternoon sun, and even when it's 118º outside with the full intense, blazing, blistering sun hitting the garage doors there is no heat intrusion.

 

[MountaineerTom]

Oh wow. Mine faces west so it gets full afternoon and evening sun. In the dead of summer, the “factory” foam on mine is pretty warm when you touch it. The bits of metal that are visible are hot.

 

[MountaineerTom]

I’m not even sure what the factory foam thickness is. If I had to guess, it say 1/2 to 3/4 inch. It has that textured like covering on it. This was a few years ago.

 

[Zorba]

I got a "klt" of foam boards for mine - full west facing. Is it the best solution? Probably not, but it made a HUGE difference in interior heat. I don't know why people and/or contractors are so fucking cheap as to not install insulated garage doors as a matter of course, the price difference is almost nil.

 

[Irun]

Now you're giving me something else to do that I know needs to be done but wasn't thinking about!

 

[MountaineerTom]

I got a "klt" of foam boards for mine - full west facing. Is it the best solution? Probably not, but it made a HUGE difference in interior heat. I don't know why people and/or contractors are so fucking cheap as to not install insulated garage doors as a matter of course, the price difference is almost nil.

Mine came with some insulation. But there’s room to add more. Since I got the new heat/air unit, I want to make the door more-better.

 

[Zorba]

Mine came with some insulation. But there’s room to add more. Since I got the new heat/air unit, I want to make the door more-better.

You'll probably need to re-balance the door once you get the new stuff added. My attempt at doing that didn't end well...

 

[KennethS]

Oh wow. Mine faces west so it gets full afternoon and evening sun. In the dead of summer, the “factory” foam on mine is pretty warm when you touch it. The bits of metal that are visible are hot.

I cut my own panels and shoved small pieces into the “gaps” between the door panels, so the metal “ribs” don’t get as hot as they would otherwise. I should fully disclose that the garage still gets hot, but that is unavoidable when it’s 110+ for 30-40 days and I don’t have an AC or swamp cooler in the garage.

 

[KennethS]

You'll probably need to re-balance the door once you get the new stuff added. My attempt at doing that didn't end well...

I didn’t have to. The foam boards for the 16” double door likely weigh less that a couple pounds.

 

[Zorba]

I didn’t have to. The foam boards for the 16” double door likely weigh less that a couple pounds.

My didn't weigh much, but it was "enough". *shrug*

 

[John Cooper]

Folks just can't hide money anymore, insulting garage doors and such.......

 

[sab]

My shop will eventually have HVAC in it (mainly A/C for the hot Texas summers). My two bay doors are 14' wide x 13' high, and because they are so big, I went with an overhead door with sheet metal on both sides and 3" polyurethane inside. It was the highest R-value I could get, and those two doors were very expensive. I also spent a pretty penny on closed-cell spray foam on everything else. I justified the cost of those by the electrical cost savings over time, but those calculations didn't account for the fact that it's been over five years without A/C and will probably be several more before I get to the point of installing A/C. Just too many projects...

Even though the costs may never be recovered, I will say that even without A/C, the shop's temp is always much more comfortable than ambient, so I don't feel bad about paying that much. Comfort, especially at my age, is very important for my sanity!

 

[tworley]

Insulating the garage door is on my to-do list - I insulated the walls a couple years ago and it made a massive difference. The garage door is the last real big heat sink.

 

[MountaineerTom]

My walls and ceiling are insulated pretty well.

I ended up just putting two layers of the Reflectix stuff. We’ll see how it does when July and August comes around.

 

[FarFire70]

I did foam board. It's a 2-car-wide door. I measured each section separately as there were only a few that were actually the same height & width across the door.

I cut it in the Lowe's parking lot to fit into the SUV.

You can see the boards on the ends of the door (left side in this pic) allows the board to go about 2" behind the hinge side and about 0.5" on the other edge - so it was cut in half to install. The middle support on the door is flush (no room for the board behind) so that I could keep board as 1 piece.

Foam leftovers were used as spacers to push the boards up against the door.

After the foam was added, released door from the garage door lifter and weighted the door on a bathroom scale. Used that to math out (online calculators available) how many turns I needed on the springs (torsion spring on this door). I then fully released the springs and re-spun them since I wasn't positive how many turns were already on them.

Been working great for 2 years. Noticeable temperature difference. You can see the temp across the panel (65*) compared with the temp of the metal of the door (45*) - that 45* would have been radiant cooling of the garage... Same applies in the summer to keep the garage cool - though I usually run the door open if I'm out there in the summer.