Attach sheetrock to blueboard insulation?

[mikec35]

I am looking for a quick, inexpensive way to insulate my open ceiling in my garage. I plan to put either sheetrock or some other kind of panels on the ceiling at a much later date, but in the mean time need some way to hold heat / air in that is better than open space. I was thinking of using 4 x 8 sheets of foam nailed to the underside of my 24" trusses. Question is can I install sheetrock directly over the blueboard at a later date and will it look wavy or are there any other suggestions to achieve what I am looking for? I am completely tapped out on my 28 x 32 garage project and will need a year or so to recover funds to properly complete the ceiling and walls. Thanks

 

[Shocker]

Hey Mike, here are is a link that cover this exact topic:

http://homeguides.sfgate.com/apply-drywall-over-rigid-foam-board-interior-ceiling-29340.html

 

[trbomax]

Ive been doing it that way for 30 yrs on cielings and walls.We built 2 homes and 3 shops that way. The hardest part is running the screws on the sheetrock because its very easy to compress the foam and make for a wavy surface.Do not spare the adhesive and be sure to use one that doesnt eat up the foam.I use adhesive between the foam and frameing members also and attach the foam with cap nails.

 

[Ksullivan]

Is there a way you can put the foam between the trusses and possibly utilize tyvek tape as an air barrier between the sheets of foam? I would set the foam up flush with the face of the trusses so then when you need to screw the drywall up you should be able to screw it up tight to the trusses with no wavyness

 

[mikec35]

Thats what I was thinking, maybe putting the foam between the trusses but not sure how you could hold in place. I wonder if stapling plastic to the underside of the trusses then spraying the loose paper insulation will work. How heavy is that stuff. I just don't have the money or time to do a ceiling right now. Thanks for the replies

 

[jvitez]

Where are you located?

If you're in a cold climate, you probably will need a vapour barrier on the warm-in-winter side. You could staple up 6 mil vapour barrier and leave it at that until you can drywall the ceiling. I've been in garages that have insulation in the wall and only vapour barrier on the ceiling, and it's surprising how effective it can be in warming the place up. It doesn't insulate, but it certainly keeps the attic vent air from blowing into your work space.

Doing it this way will save a lot of money as foam board is expensive and vapour barrier is pretty cheap. With vapour barrier and drywall you can use the cheapest method of ceiling insulation when you're ready: blown in cellulose or fibreglass (I much prefer cellulose).

 

[mikec35]

I'm in Asheville,NC. Doesn't get real cold but there are usually 2 months out of the year where it gets pretty cold, especially at night. I think the plastic sounds like the way to go. If I put furring strips up do you think it would support blown in insulation?

 

[Ksullivan]

I would rip down some 2x and nail them up from the surface of the truss the required thickness of the Blueboard you are using then use those plastic cap nails and adhesive to stick the Blueboard to the 2xs that you nailed to the truss.

 

[jvitez]

If I put furring strips up do you think it would support blown in insulation?

It might, but I wouldn't put a whole 12" in. Honestly, I like to do things once and do it right, so I'd just use the vapour barrier by itself for this winter. Put some heat in the garage and see how it goes. When you're ready do a proper drywall or OSB ceiling and blow in as much as you need (I'm not sure of the R-value recommendations for your climate).

 

[trbomax]

It might, but I wouldn't put a whole 12" in. Honestly, I like to do things once and do it right, so I'd just use the vapour barrier by itself for this winter. Put some heat in the garage and see how it goes. When you're ready do a proper drywall or OSB ceiling and blow in as much as you need (I'm not sure of the R-value recommendations for your climate).

when I do a cieling I cut the board to be a friction fit between the trusses or joist,which ever it is.You cant get a good enough fit to hold it there so I use 5" deck screws run thru the wood and into the foam. Theses act as pins to hold it up.Then I use regular painters caulk to fill any open gaps,and wipe it down with a plastic spreader. If you search for a thread called "trbo's wall construction" I have pics and a tutorial.