Drywall and insulate garage

[yupyup]

Afternoon,

My detached garage was built around 1978 gable style roof I live in Texas and it’s insanely hot. I want to insulate the garage and based on reading this forum the two leading options are drywall or corrugated steel.

Problem. Garage is about 21x26 with only 5, 2x10’s spanning the 21ft.
Reading up, hanging anything from the ceiling should be 16” on center. Mine are like 4-5’.

My question. Is 2x10 sufficient? Do I just add them until I’m 16” on center across the garage? Or can I do 24” spacing with strapping?

I plan to blow in insulation after. I am in the early planning (dreaming phase) right now. So let me know what you think or if there is another product or method.

Thanks!

 

[ericm]

Also plan for ventilation of the enclosed attic space both down low and up high. Code is ventilation area equivalent to 1/300 of the roof area (or is it building sq ft?). Not to say that you need to meet code, just as a guideline.

Drywall is not all that heavy to need 2x10s but it will need to be supported more than every 4'. White metal (29g R panel painted for interior use) can span farther without support.

 

[yupyup]

Yes, ventilation was step one. I’ve installed soffit vents and the roof already has a ridge vent.

Thanks for the info on the metal panel. My goal is insulation to make it a more usable space in the summer. I don’t care if it’s drywall or something else.

Thanks for the info!

 

[75gmck25]

If I am seeing things correctly in the picture, that framing is different than I would expect. Most of the time the joists in the ceiling serve as rafter ties, and they run between the ends of the roof trusses (a shorter span), usually with 16" spacing. They keep the rafters from spreading out, and only need enough strength to hold up a drywall ceiling. My house only has 2x6's for the attic floor.

You can ventilate the attic using a ridge vent and soffit vents, and then insulate the ceiling. Make sure you have plenty of vented opening,, both high and low, and let natural heat convection clear out the hot air.

Or you can have a company add spray foam insulation on the roof deck, close up the attic vents, and use it as conditioned space. Probably the only good reason for spending the additional money to convert it to conditioned space in Texas is if you plan to put an A/C system and vents up there.

 

[tarmy]

I just did the same project last year. My trusses were 24” OC…used 5/8 rock and screws…no issues. You need to scab in some intermediate ceiling joists and space as needed. rewired the whole garage and added insulation as well.

 

[Metal-Marc]

You must love sanding with that mud job. ^^

 

[yupyup]

If I am seeing things correctly in the picture, that framing is different than I would expect. Most of the time the joists in the ceiling serve as rafter ties, and they run between the ends of the roof trusses (a shorter span), usually with 16" spacing. They keep the rafters from spreading out, and only need enough strength to hold up a drywall ceiling. My house only has 2x6's for the attic floor.

You can ventilate the attic using a ridge vent and soffit vents, and then insulate the ceiling. Make sure you have plenty of vented opening,, both high and low, and let natural heat convection clear out the hot air.

Or you can have a company add spray foam insulation on the roof deck, close up the attic vents, and use it as conditioned space. Probably the only good reason for spending the additional money to convert it to conditioned space in Texas is if you plan to put an A/C system and vents up there.

Yes- roof runs the long axis of the garage. House was built in ‘78 I plan on bolstering the rafter ties while I have good access then hang a ceiling.
Yes- A/C in the future is the plan. Likely a mini split. But not in the budget yet. Thanks for the info! I’ll try to post a few more pictures

 

[yupyup]

I just did the same project last year. My trusses were 24” OC…used 5/8 rock and screws…no issues. You need to scab in some intermediate ceiling joists and space as needed. rewired the whole garage and added insulation as well.

Finished project looks great! Thank you for sharing. So 24” OC will work. Thanks!

 

[tarmy]

You must love sanding with that mud job. ^^

Yeah, I am a bit overzealous with getting the mud on. I hate drywall. Up where we are there is no labor due to all the construction people fully employed and contractors charging inflated prices…they won’t even do a small job like this….because of the Dixie fire 3 years ago. So many people got burned out that they will be rebuilding people’s places for 10 years…so I load it up and sand it off!

 

[PopcornSutton]

Why not run 2x4s perpendicular to the framing 16"o/c, add blocking where you need it.

 

[yupyup]

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[yupyup]

Why not run 2x4s perpendicular to the framing 16"o/c, add blocking where you need it.

True, but then all the extra weight would be on the 5 joists spanning just over 21 feet, and those joists are not really designed to be load bearing. Based on what I see

Quote

 

[PopcornSutton]

The drywall will weigh a lot more than the 2x4s.

 

[yupyup]

The drywall will weigh a lot more than the 2x4s.

Yes, that’s why I asked the question on joist spacing. Seems like adding joists 24” OC will be sufficient plus/minus strapping if I want 16” OC.

 

[PopcornSutton]

If it were me, I would consider using 1/4" luan plywood and use lattice strips to cover the **** joints. It really looks good and a damn site easier to install, no finishing, then paint it.

 

[yupyup]

Plywood sounds awesome. I’m assuming 1/8th of an inch would be too thin.
But by the time I hang drywall, mud, tape, mud, sand and sand for days because I’m not good at muddying. I would certainly save a lot of time zipping up 1/4” plywood.

Goal is insulation and later a mini split.

Thanks for the reply. Have you done this or seen it done? If you have pictures or notes please let me know. Thanks!

 

[tarmy]

1/4 will sag, especially with insulation sitting on it. I would still put in some intermediate joists and use 1/2 with drywall screws…just my take.

 

[PopcornSutton]

tarmy, I never said to not put in the 2x4s at 16"oc.

yupyup, I've never seen 1/8" plywood. 1/4 is about the thinnest and luan has a halfway decent look to it. I've seen it done many times, but don't have any pics. Keep the lattice straight and neat, cause that's the accent you'll see.