Insulation, Radiant and Vapor Barriers - Need Help Insulating Garage Ceiling

I would like to insulate the ceiling of my garage. It get quite hot in the summer and chilly in the winter. it is your typical 3 car garage approx 700 Sq ft. The trusses are 2 x 4, 24 inches wide. My question is when i looked at home depot there were no 24 inch wide x 3 1/2 inch batts can i use a thicker batt what are my options? Does it matter if I use thicker batts? I no nothing about insulating help is appreciated as I plan on doing this myself.

You dont say is there a ceiling up there now or not . But anyway you can get a R-19 24" wide and you would be better off with this anyway. Paper to the room side or paper down.Dont know what you have for vents in the over hang here but you should put up Foam rafter vents first so air can get from the over hang vents up into the attic there. you need some gable vents or roof button vents there also ED;)

Ed the garage is sheet rocked walls and ceilings there is gable vent and soffit vents. When you say r-19 24" does the thickness of the batt make a difference? as the truss is 2 x 4's.

thanks

Bob

No it can stick up above the 2X4 up there . Now you said its all drywall. So you want to put the foam rafter vents in first so the air can come up from the vent there in the soffit. Then put the R19 insulation in paper side down and push it tight to the foam vents. ED