Reflective Aluminum Radiant Barrier amazon 60 dollars. Takes 1 roll 50 ft for a 1.5 garage door takes about 1 hour very easy to do with a straight edge and a box cutter. no tape or glue.

We moved in about 7 years go and did it myself with the same insulation that the villages used in stucco homes, rigid foam board two pieces thick and cut to fit exactly with no glue, then tapped with metal duct tape, the shiny stuff. Works well and quiets the door operation and reduces heat transfer. Purchased from Lowe’s. And was able to cut 4 x 8 sheets in half for SUV transport. Very little waste.

DIY from Lowes
 

I bought the styrofoam panels from Lowes. They were inexpensive and did the job my self. Many of the panels had to be cut with a utility knife and you get styrofoam particle all over. I also had to remove some of the hurricane support metal. The project took some time, but I am happy with the result and it definitely lowers the temperature.

Got mine from Lowe’s easy to put up I used no glue it’s been fine for a year now.

Mine as well. It's OK. Your basic garage isn't all that great

What do you mean by ‘split’? And why are you doing this? Is it so you will lower the temperature of your house? I’m so confused.

We did our garage door ourselves. We used a kit from Amazon. I attached a photo of the exact product. The second photo is our garage door. There wasn't a glue smell. Two-sided tape was included. We also paid Romac to blow insulation in the attic above the garage. The garage still gets hot on the hottest days, but it's not overwhelming.

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Here are two links Make huge difference well worth it. Don’t leave windows in cover in garage. On door cover them with panels or very least Gila Film. Same with window in garage. Gila film takes two
people. Also, consider insulation above the attic. We did Solar guys for that although you could DYI it.

Lowes
[url=https://www.lowes.com/search?searchTerm=garage%20insulation%20panels

Amazon

Not letting me post link. Go to Amazon and type garage door insulation kits.



Gila film

[url=https://www.amazon.com/s?k=Gila+film&crid=2OYILGMIUOIVV&sprefix=gila+film %2Caps%2C125&ref=nb_sb_noss_1]

[url=https://www.lowes.com/search?searchTerm=gila+film

Have a good cooler day.

I did my garage door. I ordered a kit from Home Depot. You need a really sharp knife to cut the foam. You’ll have to remove a couple of the braces on the door to do the job, but they’re easy to remove/replace. I didn’t glue my panels to the garage door as I cut them to fit tight. Total cost was about $250 for a 1-1/2 garage. The insulation does help with the heat in the summer and keeps the garage warmer on the few really cold days we have.

Romac Kit
 

Ditto on Romac. I had them do the installation of their kit and adjust the springs. Also had blown in insulation above garage and added a mini-split.

Call Romac..they have the exact kit