Insulating a garage door using foil-sided yellow foam board

[Dave MacArthur]

This comes up pretty often, thought I'd post some pictures.

The 1" thick foil faced yellow foam board sold at Home Depot for 9$ a 4x8 foot sheet or so, is vastly better than styrofoam for this. HD actually sells kits of pre cut styrofoam panels for this, but they didn't actually measure the same as my door openings, and would have to be cut again anyways... at 5 times the cost.

Also, the R value for the foil foam is much better than styrofoam. And lastly, it is much easier to work with --cuts in 2 passes with a utility knife, leaves no mess... not like all those little styrofoam balls. And no static making all the bits cling to you like styro.

Measure the panel openings, then measure the full height of the inside, which will be like 3/8" more due to lips on the panels. Mark your foam, cut your first panel full size and see if you can fit it in by sliding it UP into the slot, then pushing it in. Probably not. So with the foam pushed fully up, mark the bottom edge of the foam so it will pass over the top of the lip, then trim that edge (probably 1/4" or so). Fit it in.

All my panels fit in tightly, but for some reason the bottom panel is different--taller lips. So on THAT one, I just cut the foam to the full height, then free-hand cut a slice horizontally across the foam part way through, and then just folded the foam board in half along that cut. So it is shaped like a V. Then just push the two legs of the V folded foam panel into the top/bottom garage panel lips, and push into place. The foam snaps in there with no desire to unfold, and the cut virtually dissappears.

You can do a single garage door with 2 4x8 foam panels, about 16$, and it takes 15 min or so.

If you want, you can open/close the door a few times so the foam panels are resting fully OUT against the lips (not pressed in up against the garage door, leaving an air gap). This gives better insulating properties, and is the way they will naturally rest. Then just run a can of "Great Stuff" expanding polyurethane foam around the edges of the individual panels to "seal" them in place with no air leakage, clean up the expanded foam later with a knife.

Works great, dropped my west-facing Phoenix AZ garage temp about 30 degrees in the summer. No lie, it was like 130 in there near the doors with the sun on it. Maybe even more of a drop. I would recommend it to anyone for both thermal insulation AND sound proofing.

Enjoy!

[Don Bullock]

Dave, thanks for the information. That's exactly the type of post I will be needing as soon as my new shop is built. http://www.sawmillcreek.org/showthread.php?t=82142 I've printed it out for future reference.

56 days and counting!

[Jim Meier]

Thanks, I was just talking to my wife about this yesterday. I think I'll get it done next week.

[Joe Jensen]

Dave, I have been considering that upgrade too. What thickness did you use? Did you cut it as large as possible? I was planning to do it that way and then split each lengthwise to install them. I was going to put aluminum over them to cover the foam.

[James Hart]

Dave,

Ironically, the electricians are in the garage right now installing a sub panel, 220 for AC and my PM66, new lights, dedicated circuit for dust collector, etc.

AC unit coming Monday, followed by insulation and drywall repair.

Do you have any idea what the R rating is for the material you used? It looks great and is much less expensive than what I was considering.

Jim

[Jim Meier]

Well, I insulated the garage door this weekend. although it doesn't look as pretty as yours, it sure does a great job!

I used 4 sheers of the foil sided foam and 8 cans of great stuff on the sides and behind the panels. They are tight and there is no room for spiders and bugs anymore.

I wasn't so careful with the foam, so there are foam lines around all edges, but its not about looks

total cost = $104
temperature reduction on day 1 = 25 degrees!!!

Thanks for the motivation!

Jim

[Todd Hyman]

Dave,

Thanks for the info. Does the foam board come with the white backing or is this some other type of panel? Can you post the sku # for the boards you used? Also did you have to glue it in place?

Todd

[Dewey Torres]

I looked for these here and did not find them. Is there a web site product refernce available that I could take to the store? What is the actual product name?

Thanks

Dewey

[Dustin Thompson]

I think most of the foam board products are somewhere around an r-value of 7 per inch. Oops, maybe not-here's a link to one of Dow's products:

http://building.dow.com/styrofoam/na..._sheathing.htm

Dustin

[Dave MacArthur]

The foam boards I used were just yellow foam with foil surfaces. I bought the thickest they had at Home Depot, which was an inch I think; it just has to be thinner than the depth of your garage door panels.

The R value was 9, I believe... not sure, but it was more than any of the other insulation sheets they had at HD.

Unsure of the SKU, but I found them stacked on the store side wall near the concrete products and lumber, along with styrofoam and also the "blow in" cellulose insulation.

There is no need to glue them in place, they fit very snugly-- you don't really need the Great Stuff expanding poly, but it will seal up a bit more and hold them firmly if you do use it.

Joe, as it turned out I cut the inserts just about 3/8" smaller than the height of the door panel interior... if you go look at your panels, you'll see there is a lip at top and bottom you have to insert the foam around, same deal as sticking a window screen in... you shove it UP under the top lip, then try to shove it in over the lower, which blocks it. So, it has to be about the height of 1 lip shorter, to slip over the lip.

On the panels I DID cut lengthwise, fold and insert and press flat, they worked great also... but that was only required on the bottom panels which had overly large bottom lips. All the others really fit snugly enough just cutting them 1 lip short, and squirting some foam in if required.

I'll try to remember to get the sku next time.

[Danny Thompson]

The foam boards I used were just yellow foam with foil surfaces. . . .

I'm confused. Why do the panels in the pics look white?

Also, about the expanding poly, did you shoot it around all four edges? Between the panel and the top and bottom lips? Between the panel ends and the door face?

Thanks for the idea and information.

[Dave MacArthur]

they look white because they are reflective and I have a white garage They're tin foil looking really.
Poly foam--as I said, not required at all. If you want to use it, it's just like "caulking", just run it around the edges if needed. It would keep any heated air from squirting out the sides. I did some of mine, but not all--the panels were so tight in there, it didn't seem needed. Really it expands so well, that just holding the panel up against the top edge and squirting it into the bottom lip gap seals it well.

[Danny Thompson]

Cool, thanks.

[Paul Fitzgerald]

I know this thread is a couple months old, but I was wondering if anyone else found the foam panels Dave referred to. If not, did anyone find anything that worked for you?

I checked several Home Depots and Lowes and here is what I found:

• 1/2" Foil Faced R-Max R-Matte Plus 3 (R3.2) - $10.98 @ HD (SKU 754-404)... cream colored with aluminum foil-ish facing
• 1/2" Owens Corning FOAMULAR (R3) - $10.61 @ HD (SKU 409-923)... pink
• 3/4" Owens Corning FOAMULAR (R4) - $13.15 @ HD (SKU 104-863)... pink
• 2" Owens Corning FOAMULAR (R5) - $22-something @ HD (SKU unknown)... pink
• 1/2" Foil Faced Perma-R Polystyrene (R4.97 with 3/4" Airspace) - $9.44 @ Lowes (SKU 41503)... cream colored with what looked like window tint film (definitely not aluminum foil)
• 1" Dow STYROFOAM (R5) - $16.47 @ Lowes (SKU 14546)... blue

I know next to nothing about insulation, so I don't really know what to choose. From what I've gathered, the higher the R value the better. And an airspace seems to be good as well.

I also don't know much about garage doors. Mine is metal. Maybe aluminum... maybe steel. Dunno.

I do know that the garage door has 1-1/2" of clearance between the "raised panel" looking flat part and the lip (2" if you don't count the raised panel). In other words, I could fit a panel of up to 1-1/2" thick into the opening and it would be captured by the lips.

So what I was thinking was pick up the blue Dow panels and leave a 1/2"-1" airspace behind them. It'll take 4 panels @ $16.47 to insulate my garage door. With tax, the total would come to $71.97.

One more thing... Could I paint the show side of the foam with latex paint?

Thanks!

Paul

[Joe Jensen]

The Home Depot near me as nominal 1", 1,5", and 2" thick sheets with shiny silver foil/plastic on both sides. The 1.5" was actually slightly under 1 3/8" and I was able squeeze it into the opening with some patience (maybe 10 min per panel). I chose to go this way to maximize the R value. I think I ended up with R 12. I too used spray foam to seal the sides and top and bottom...joe