Insulating detached garage ceiling questions

[vavet]

Truss construction of a 24x32 garage. I decided I wanted to do blown in fiberglass insulation. The ceiling drywall is complete. I’ve cut an access hatch, 22.5 x 30 inches. The ceiling is 12.5 feet above floor level. I’ve put 1/2 inch ply along the 22.5 inch side, perpendicular to the trusses. Now I have to install the 30 inch long pieces parallel to the trusses. I need R38, which is 13.25 inches.

I’m ready to install those pieces to hold the insulation back by screwing them to the side of the truss, opposite of the access door. I’ve cut them to 16 inches, which leaves it a little higher than the insulation. How do I install those plywood pieces and then get myself out or back into the attic?

I’m using a double stack layer of rolling scaffolding by climbing the ladder right up into the attic. My rough plan, unless someone can offer a better idea, is to blow most of the attic. Then I will attach the last 2 plywood pieces while standing on the horizontal portion of the scaffold set to about 11 feet. Then I can blow the area immediately around the access hatch while still standing on scaffold. Then I just have to maneuver myself back onto the ladder portion.

I’m concerned about my plan because I’m not terribly comfortable working at heights.

 

[maxpat82]

Sound good to me.

I did put a 8' stepladder on top of one section of the exact same scafolding that you have.

If you do: screw it down.

those scafloding are good to be stacked, but at 12' high they might get wobly a bit.

you could rent 5'x5' scafolding too...they are way more stable.

 

[larry4406]

Put you plywood curb fully in place permanently.

Build a landing up there that you can stand on that is connected to your curb that will permit the blow in under your landing at full depth.

Stand on the landing while blowing vs being on your scaffold.

?

 

[vavet]

I'm coming up with something strange on Lowes and HD pricing on this blow-in insulation. They both offer volume discounts on these bales of insulation. The minimum quantities for high volume pricing are slightly more than what I need. For the blow-in fiberglass I need 26 bales, minimum for high volume pricing is 30 bales
It ends up being more expensive to buy 26 bales than it is to buy 30 bales.
Theres a similar phenomenon with the cellulose insulation, but the quantities are greater - I need 88 bales, volume pricing starts at 100 bales.

It might just be time to go into the store to talk to someone.

 

[StreetGLi]

Can't go wrong with a little extra insulation up top, especially if it's cheaper!

Sent from my LG-H873 using Tapatalk

 

[kbs2244]

How are you venting that attic?

Your roof holes should give you access to spray in the last few square feet.

 

[vavet]

How are you venting that attic?

Your roof holes should give you access to spray in the last few square feet.

Don’t understand what you’re calling roof holes. Can you explain?
The soffits are perforated and the roof has a ridge vent.

 

[dfiler2]

I would leave a piece of plywood out so you can get up there and walk on the rafters to get to the far end. I would take up some spray paint and put a line on the rafter braces at the depth you want your insulation,
I would then blow it in until you can reach the rest from your hole, then put in the last piece of plywood and finish it up.

As mentioned I would do the 30 bags and put in some extra.

 

[James-W]

Don’t understand what you’re calling roof holes. Can you explain?
The soffits are perforated and the roof has a ridge vent.

I think he means roof vents, but you don't have them, you have a ridge vent.

 

[IBenDcars]

Um, buy 30, use 26 return 4. You saved money on original purchase and get a refund on unused product.

 

[Mdluke]

Um, buy 30, use 26 return 4. You saved money on original purchase and get a refund on unused product.

^^^ This!!

 

[quad]

Truss construction of a 24x32 garage. I decided I wanted to do blown in fiberglass insulation. The ceiling drywall is complete. I’ve cut an access hatch, 22.5 x 30 inches. The ceiling is 12.5 feet above floor level. I’ve put 1/2 inch ply along the 22.5 inch side, perpendicular to the trusses. Now I have to install the 30 inch long pieces parallel to the trusses. I need R38, which is 13.25 inches.

I’m ready to install those pieces to hold the insulation back by screwing them to the side of the truss, opposite of the access door. I’ve cut them to 16 inches, which leaves it a little higher than the insulation. How do I install those plywood pieces and then get myself out or back into the attic?

I’m using a double stack layer of rolling scaffolding by climbing the ladder right up into the attic. My rough plan, unless someone can offer a better idea, is to blow most of the attic. Then I will attach the last 2 plywood pieces while standing on the horizontal portion of the scaffold set to about 11 feet. Then I can blow the area immediately around the access hatch while still standing on scaffold. Then I just have to maneuver myself back onto the ladder portion.

I’m concerned about my plan because I’m not terribly comfortable working at heights.

If that was me I would have placed plywood decking over all the ceiling joists and then built it up with layers of rigid insulation. 8" would give you R40. Then you can top that off with luan and perhaps even house wrap. But you would need easy access with a sturdy, large attic ladder rated for 350-400 lbs. I did this with our existing home attic. How deep are your ceiling joists? 2x6 or 2x4? You can get another R13 or R19 between the joist and it that case 6" of rigid would push you over R40.

I really hate the idea of blown in insulation. It is quick but creates such a mess and overtime will compact and lose some insulation value. And if you ever have to go back in there to do anything it will be a complete mess and you'll disturb the R rating by stepping on it etc.

I did add blow in insulation in our knee wall attics and one of the smaller attics. But the main attic is all rigid.

 

[acer66]

Can't go wrong with a little extra insulation up top, especially if it's cheaper!

Sent from my LG-H873 using Tapatalk

More insulation is better.

 

[vavet]

Wanted to close the loop here. I had a friend come over last Friday to help. He fed the blowing machine while I blew it in the attic. I did the area around the opening as I described. Going in and out of the attic is easier with the scaffolding about halfway under the opening, so I can use it as a ladder and go straight up into the attic. For the last bit, I had my helper move the scaffold so I had someplace to stand or kneel while blowing the last bit by the opening and attaching the plywood baffles. When I was done, I climbed up one last time and perched on the lower chord of the trusses while he moved the scaffold back so I could step down onto the ladder portion of the scaffold.

The machine works well, but it’s slower than I expected. I will have to rent the machine again to finish the blow for the walls. I’m about 1/3 of the way done with the walls.