# Benefit of insulating my attached garage?



## Windows on Wash (Aug 30, 2011)

Some insulation on that garage door that combines the radiant barrier might help along win the walls and ceiling. 

There is an attic...correct?


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## SeniorSitizen (Sep 10, 2012)

Definitely insulate the walls and ceiling. If there are east or west facing garage windows and/or a door with glass, outdoor blinds are a must have unless there are shade trees that will suffice.


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## Ron6519 (Mar 28, 2007)

Then put in an A/C.


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## crispy1138 (Aug 3, 2015)

Thanks for the replies. It seemed the obvious thing to do, but the seemingly obvious doesn't always mean the right thing. My insulation project begins! I will likely install a mini split AC when I'm done with the insulation. I don't think adding a window for a window unit is practical, and a portable unit would be in the way and a mess to vent properly.


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## SeniorSitizen (Sep 10, 2012)

You'll be the envy of the neighborhood with a heated and cooled shop.

Monitor the HVAC units filter closely when wood working, even if you should at some point install a good dust collection system. Sanding is the worst and I would recommend doing as much of that outdoors as possible.


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## Gary in WA (Mar 11, 2009)

Insulation should be done rather than a RB, if one needs to choose. Insulation will slow/stop heat transfer by *conduction*; a radiant barrier will slow/stop heat transfer by *radiation*, a housewrap on the insulation will slow/stop heat transfer by *convection/*air currents. Air seal the attic, then insulate, at least to code minimum for a house; http://energycode.pnl.gov/EnergyCodeReqs/index.jsp?state=Texas

And the RB (on rafters is best) needs shiny side toward attic, with opening at top/bottom to move bulk attic air; http://www.mytexasinspector.com/pdf/Radiant Barrier Fact Sheet DOE.pdf

Gary


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## ChuckF. (Aug 25, 2013)

Insulation above the ceiling in my garage made a big difference in both Georgia Winter and Summer. Look at gasketing your garage doors as well.

You have to start with insulation above the ceiling because it's the most cost-effective thing you can do especially if you do it yourself. It should always be step one. Rent a blower, make sure you have baffles if you have vents.


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## crispy1138 (Aug 3, 2015)

Thanks all,

As I mentioned in my original long post, I have radiant barrier in entire attic and garage on the rafters, a solar fan at the center apex of the roof to suck out the reflected and otherwise hot air, blown FG on top of original cellulose to R38. Giant difference with all of the above. Foil sandwiched bubble stuff with a sealed air gap on the aluminum door, with some extra gasket stuff to try and stop any drafts. Thanks for corroborating the benefits of each. Over garage and main attic space shown.

Next step is filling the 2x12's above the garage with blown FG and baffles over the soffit vents, should be close to R38, may or may not do it myself since I have a contractor I like using that gives me really good deals. Everything I've heard is yes the ceiling is a really important place to start since heat moves vertically and it will make the biggest difference.

I may take off the sheetrock and put bats in the 2x4 walls, that's a weekend DIY with a bud to help me. I may put in the mini split before I tear down all the sheetrock to see if it needs the help. Rather not rip all the walls down if it's cooling "well enough", we'll see.

My attic access is in the garage, a 2x4 foot opening with folding ladder. Any thoughts on the practical and best way to insulate and seal it?


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## Gary in WA (Mar 11, 2009)

IMO, cut some 6" slots in the RB, at the peak/bottoms to vent any heat flux from below, otherwise it will stagnate at the peak without any air movement. Adjust/support the 6" flex ducting bends/kinks to improve airflow at the already reduced product to help against back pressure; http://rockwallcontrols.com/Residential/?tag=air-ducting

More detailed; http://www.mmmfg.com/pdfs/060601_CC-KW_DuctTechPaper.pdf

Gary


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## marcmorgan (Aug 26, 2015)

I live in Houston and recently completed my garage. I insulated the ceiling, walls and garage door the best I could. Then bought a portable heat pump at Costco for $400. It is AC and heat. I had to put one hole through my brick wall for the exhaust. I also added new electrical runs in both 110 and 220 so that I could run more power tools and a welder. It cools pretty well in the summer. Parts of August could be cooler. If i had to replace my garage door for any reason I would do the pre-insulated ones.


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