Garage door insulation types - which is better???

[HotRodBiker]

So, I'm looking to insulate my garage door and have run across three different types.

1. Reflective Foil
2. Panel Foam with foil face
3. Fiberglass with vinyl backing

I live in Austin, TX and it gets hot here 9 months out of the year.

I've been reading numerous threads for the last 3 hours and most garage doors seem to be insulated with foam panels, some with radiant barrier foil.

My plan is to cool my garage with a portable AC unit for the time being. Again, after reading numerous threads, I now know the portable isn't a good solution but it's what I have until I can sell it.

In the mean time I'm going to start insulating my attached garage... and I'm going to start with the doors as they are giant heat sinks. 2 of the 3 walls are insulated for sure, and I'll be checking the 3rd wall this afternoon.

The ceiling has zero insulation so that will be step number 2. Step 3 will be either insulting the 3rd wall, depending on what I discover today, or selling the portable and installing a split system (depending on the HOA).

When I'm working in my garage, I'll be in there typically 8+ hours a day, mainly wood working or some other project to keep me busy when I'm not offshore working.

I like the reflective foil because it covers the entire door and metal framing, but since it attaches to the metal framing, I would expect the foil to become conductive and less of a radiant barrier. Not totally sure how that works with foil on metal for a relatively small section and a large air gap for the rest of the door.

The foam boards do roughly the same thing as the reflective foil, but it does not cover the metal bracing/framing attached to the door. On my two, single width doors, the metal bracing runs down the middle. So, any heat transfer will radiate into the garage, but that surface area is relatively small to the overall door surface area.

The fiberglass option leaves me with the same exposed door bracing to transfer heat, but it has the highest R value.

Taking the cost out of the equation, and selecting from these three options, what is to best form of insulation for my (2) 9' wide, west facing doors?

 

[Falcon67]

This works better than you might think and it gets hot here, we're only 250 miles from you. This is 1/2" reflective foam, door faces south.

For a 9' door facing west, I'd do 1" foam. It will add some weight, but not that much. My west wall is gray and only hits 135F in the summer. When the wall was red, it ran 170~180F. Hopefully your doors are white.

 

[HotRodBiker]

Are both sides of the foam board reflective?

 

[Fixin'Stuff]

I used the Owens Corning fiberglass/vinyl kit when I lived in your area, mostly because Lowes had it for half price on Black Friday several years ago. It made a HUGE difference in the comfort level inside an insulated 3-car garage, with east-facing doors. I was also surprised at how much quieter it made the garage. It blocked most outside noise and did a nice job of making it quieter outside when I was making lots of noise inside the garage. A nice side effect was that the door itself operated nearly silently afterwards.

 

[HotRodBiker]

I used the Owens Corning fiberglass/vinyl kit when I lived in your area, mostly because Lowes had it for half price on Black Friday several years ago. It made a HUGE difference in the comfort level inside an insulated 3-car garage, with east-facing doors. I was also surprised at how much quieter it made the garage. It blocked most outside noise and did a nice job of making it quieter outside when I was making lots of noise inside the garage. A nice side effect was that the door itself operated nearly silently afterwards.

Thanks for sharing, I'm leaning towards the fiberglass and wanted some advice before making a purchase.

 

[thammel]

I did #2 myself with panels I bought at HD. Just look at the R value you can get; the higher the better. I like #2 because it's rigid and pretty tough, and looks good.

Tom

 

[ahab]

I'm looking to do the same insulated door & portable A/C soon in Round Rock with a south facing garage. It would be brutal with out.

 

[TerryH]

I did mine with 1 1/2" thick foam with the smooth backer. Easy to install and they made an amazing difference. I cool my 1200 sq.ft. 10' ceiling shop with an 18k btu window a/c mounted in the wall. I bought the kits at my local garage door supply but I think the kits at Lowes are very similar. Great insulation and easy to clean.

 

[Falcon67]

Are both sides of the foam board reflective?

Just one side.

 

[plain garage]

I have a 14' x 7' overhead door that faces east/southeast, 1/2" rigid foam with reflective backing have cooled the garage by at least 20 degrees. It used to be 100+ on a hot sunny day, now I can work with just a fan.

 

[SJP0tato]

I debated for weeks trying to answer that question for my own garage insulation (price vs material/performance). What I wound up with was Rmax Thermasheath from Home Depot: http://www.homedepot.com/p/Thermash...Rigid-Foam-Insulation-Board-W-N5150/100317819 (model# W-N5150, Home Depot SKU: 440083, incase the link dies one day)

4 sheets of that cut into 1/4's (and then cut down from there for each panel) was enough to cover my entire 2 car garage door, at just over $100 for everything.

It was the cheapest, best R-value, lightweight material I could find that didn't require anything additional, other than a couple hours to fit it into the garage door panel grooves/recesses.

I installed mine in preparation for installation of a mini-split system. Right now on a sunny afternoon on average it makes a 10-15 degree difference in the temps, so I know it's helping over the bare South-facing door.

Hope this helps!

 

[HotRodBiker]

I opted for the vinyl backed fiberglass. I was at HD to pick up some foil faced foam boards but decided against them because they compress easily, and I know they will get dinged. So far so good, it was a fairly quick install and I'm going to run my portable AC unit tonight and see how well it cools the garage down.

Thanks for everyone's input.