adding ceiling to garage

I have a freestanding 1.5-car garage, which I'd like to be able to work in, during spring and fall, to do motorcycle maintenance. The garage is unfinished, and when I tried using a propane heater, the heat just wafted up to the roof. I'm now using a pair of 1200W infrared heaters, pointed at the work area, which works somewhat (also less risk when working with gasoline!).

I was thinking that the biggest improvement would come just from adding a ceiling, to keep the warm air down (and adding gable-end vents and soffit baffles). Then, perhaps insulating the walls, ceiling and garage door if I need more warmth. Does that seem reasonable?

Regarding the possible ceiling, there are roof trusses only every third stud (3 x 18" = 48 inches between trusses). It seems like home ceilings have sheathing screwed to the underside of the joists, then insulation blown-in. But I'm unsure if that's a good plan for a garage. Also, homes seem to have joists every 18 inches, rather than every 48 inches. Perhaps there's something simpler than sheathing for a garage?

BTW, I don't need any storage above the ceiling.

 

Welcome to the forums! With truss spacing every 4', you won't be able to install sheetrock directly to the truss bottoms. Most likely you would need to strap the trusses every 16" on center perpindicular to the trusses with 1x4's, then apply your sheetrock. You will need to build in an access hole to comply with code and to allow you to insulate after the fact unless you decide to install insulation prior to sheetrock (preferred).

 

Thanks, Chandler. So if I wanted to add fiberglass batts, I would run 1x4 strapping, perpendicular to the trusses, 16 inches on center... and that would give me the 16-inch-wide channels I need to insert batts, and also something to fasten the sheetrock to. So the batting would run between the strapping, instead of between the trusses?

Where would you recommend that I put the vapor barrier?

 

I would use kraft faced insulation (or better yet, the encapsulated Owens Corning insulation) and roll it out across the strapping adjacent to each other in the 4' bays. That will take care of your vapor barrier and insulation

 

Not trying to complicate matters -- and this is the first post, glad to be here! - but if you have steep trusses consider creating floating joints to avoid truss uplift.

This can be done by the way it is attached and certain companies ( at least one) make a product for this.