Ceiling insulation

[Energyblue98]

Hello there,
I've been "renovating" my 24'x25' garage lately to turn it into a more studio type garage as I film videos in my garage. I've put up my lights, plumed all of the wiring and plugs, and have started putting up insulation along the walls. I've gotten to a point where I'm unsure of how I should insulate the ceiling. I'm torn between buying the 24" wide faced insulation rolls and stapling them up, or if I should put up the ceiling board (thin wood that I want to use instead of drywall) and then put blow in insulation on top to that. The lights are "sealed" to handle blow in insulation and I feel like that might be easier but I want to make sure I have appropriate insulation coverage. I'm also slightly concerned with the small clearance at the edges where the roof slopes down. I have the plastic gable vents to allow air to pass by but there's not much area for insulation there so I fear the insulation might end up weak near the edges.

What do you all think? The blow in insulation appears to be about half the cost per square foot than the insulation rolls.

I've attached a few pictures so you guys can see what I'm working with.

 

[Falcon67]

My old shop had nothing but R13 batts, 24" stapled between the joists. No problems. To help prevent conduction in the walls, technically the ceiling insulation should overlap the top plate. I think the loss of insulation caused by compression in that area will be minimal. You will get better insulation ROI with some sort of ceiling panels that are sealed to each other and caulked/sealed to the walls to minimize air movement up through the insulation. My current shop has an OSB ceiling, 24" OC joists and just R13 batts laid in the cavities. There was about a 25% improvement in "feel" of the space after caulking all the joints between the panels and at the walls. I can hold the inside at mid 70s with only 18K of AC while the roof deck is running 110F plus.

 

[Randy in Maine]

It would help to know your location.

 

[Firebrick43]

Cellulose will give you superior results at a cheaper cost. The area above the top plate is called the heel of the truss. Place your vents. I really don't understand what you mean by "weak" in that area. Cellulose will have better performance even in the heel area compared to fiberglass. Any compression of fiberglass lowers its r value. So trying to pack more in there is not going to help anything or give you any advantage.

Due to lack of depth the r value over the top platewill be lower than the rest of the ceiling. People that want better performance order raised heel trusses or sometimes called energy heel trusses.
Since yours is already built there are 3 options.

You could place a piece of say 3" thick eps/xps between the trusses overlapping the top plate towards the interior say 24"

You could use closed cell spray foam in this area

Just insulate it with cellulose or fiberglass like millions of other homes.

 

[Bolson32]

I'd put up a vapor barrier, ceiling panels, and blow cellulose. Way easier and cheaper and should perform better than fiberglass, like they said, especially in the heel. My house is the same way, not much room on the edges but cellulose will give you really good performance.

 

[Energyblue98]

It would help to know your location.

Sorry, I'm in Virginia. I was planning on going to R30 for the ceiling.

 

[PhantomEB]

Blow in will give you that R30 and then some?

 

[Dragfluid]

Cellulose.

 

[brewchief]

I vote for blown in, around here you can have it done for about the same cost as buying the materials and doing it yourself. Take some spray paint and mark the trusses at the depth you plan on, makes it easy to verify proper depth.

 

[ForceFed70]

Blown-in beats batt/roll insulation every time.

I also recommend the ceiling boards and blown-in solution. It'll look and perform a lot better than stapled batt/roll.

Don't worry about the edges. From the pics it looks like you have the proper baffles already to allow for the required airflow. You'd have the same problem regardless of the insulation type and yes - typically a little less near the edges.

 

[Sparkynutz]

I'm in the same boat trying to figure out how to finish ceiling and insulate on my 26x26 detached garage. I'll be using one of those 5000w electric heaters. Fleet farm had them black friday for under $70 after signing up for their credit card.

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