Garage rescue: insulating the ceiling space

One of the first things I noticed about my new house was that the garage was always either HOT or COLD. Since it’s attached to my house, I don’t really want it experiencing extremes of temperature, which I figured would translate to the house. I thought about insulating the garage door, but the door is wood and never really felt that hot to the touch. After some research, I settled on adding insulation to the open truss space to create a ceiling of sorts. The walls are already finished and insulated (for the most part) so the ceiling seemed the logical starting point.

I have a one-car garage, about 14 feet wide and 28 feet long. The trusses are 24″ on center with about 23 inches between them. Before you take on this project, make sure you measure the length of the garage, the spacing of the trusses, and count the ‘bays’ between the trusses to figure how many feet of insulation you’ll need.

Here’s the garage ceiling before:

Garage ceiling with no insulation

Open-space garage ceiling


I used R-13 Kraft-faced batting insulation but you can use whatever R-factor you prefer. You’ll need something to cover your head, glasses/goggles, face mask, old clothes, gloves, a ladder, and a staple gun. I have an electric one, but it didn’t work well at the angles I was stapling at so I ended up reverting to the old-fashioned manual one.

The first thing I did to prepare was to tack up some old molding strips as supports for the insulation pieces. That way I could hang the insulation over the strips and not have to try and hold it up while I was stapling. It was still awkward, believe me.

Support strip

Tacked-up strip


Then I hung the insulation over the strips, got up on my ladder, and started stapling every six inches or so. I tried to pull the insulation kind of taut, without tearing it, as I went.

Note: you’ll want to staple the kraft paper facing to the INSIDE of the trusses – not over the bottoms of the trusses. This is more awkward but leaves you with exposed trusses to glue wallboard to if you decide to put in a ceiling. If you are never going to glue anything to the trusses, you can cover them with the kraft. Otherwise, staple to the inside.

Insulation hanging over support strip

Insulation hanging over support strip


From there on, I just kept going, butting the ends of the strips up against each other. It took several hours but wasn’t as hard as, say, scraping off a popcorn ceiling! Some of it just entailed putting up a strip, but there were places where there were obstructions that had to be avoided. You don’t want to staple into wiring, for example. You will have to cut around light boxes and other object that you want to extend below the insulation. It’s easy to do that with scissors.

Partially-done ceiling insulation

Third of the way done


I covered the ends where two strips met each other with brown kraft paper tape. Like most of my DIY, it’s not professional, but I hope it will improve the extremes of temperature and save me heating & cooling $$.

Finished ceiling

Finished ceiling


I’ll report back on what happens! Now – eventually I will be adding a ceiling. I’ve decided to do this by tacking molding strips along the bottoms of the trusses, lengthwise, to create little ledges on either side. Then I’ll slide wallboard panels or other panels cut to size up into the bays and create a ceiling that can be removed in sections for access to the space above. More on that as I do it!