I'm about to start putting the OSB ceiling up in my 40X44 garage I've been building. Planning to use blown in fiberglass in the attic area. Standard 4/12 trusses and the attic will be closed off more or less permanently aside from any possible maintenance needs in the future. Never used that type of insulation before, wondering how many access hatches I should have?
Attic access for blown insulation
- Thread starter ExxWhy
- Start date
Jess
Well-known member
I have a 32x40 and only one access hatch, with a drop down set of stairs. In the attic, I built a catwalk through the trusses above the insulation height to let me get around without having to 'swim' in the blown in stuff. It made doing the insulation a lot easier too.
One should be sufficent but make it large enough that you can easily fit through it. Hopefully, you'll never have an issue but make it large enough for a FF with an air pack to get through other wise, they will make a larger hole and it won't be neat.
If your trusses are 24" OC, make it that wide and about 3-4' long. Simply screw some rigid insulation panels to the backside of the panel and you shouldn't have much heat loss.
This is what mine looks like in the house garage.
If your trusses are 24" OC, make it that wide and about 3-4' long. Simply screw some rigid insulation panels to the backside of the panel and you shouldn't have much heat loss.
This is what mine looks like in the house garage.
MagKarl
Well-known member
My house has boxes around the access holes to keep the blown in insulation from pouring out through the hole. Seems like it works pretty good but makes climbing up there a little more difficult.
JunkYardDawg
Well-known member
Just a thought... is OSB accepted fire code material? Around here, garages have to be metal or sheetrock.
Slowgsr
Well-known member
I made two hatches since my pitch is so low that I can't get up there through the insulation. Mine are roughly 24x24 and I just trimmed them out so they look nice and my hatch sits on the lip of the trim
Just a thought... is OSB accepted fire code material? Around here, garages have to be metal or sheetrock.
Welcome to GJ. Ceiling and wall coverings is subject that can be and has been highly debated.
Most agree to disagree on the subject yet almost all will agree it becomes a different matter when the space is attached vs. detached.
OccupantRJ
Well-known member
I am in the process of installing my ceiling now, and have provided a 24" x 24" opening along with a catwalk down the length of the attic to facilitate the blowing in of insulation. I get free 1x 6 x12 foot crate boards from work, so building the catwalk is a nice freebie. I also used pieces of 1x4 on each sheet joint between trusses to insure against sheet buckling.
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TurnipTruck
Well-known member
I prefer to leave an access door in the gable end of the outside wall and not have any penetrations through the ceiling.
BruceMc
Well-known member
This is the best way. Access through vents in the gable ends. If at all possible you should avoid any penetrations through the ceiling. They are almost impossible to adequately seal unless you permanently close them off later, and then you have heat loss problems due to the chimney effect.
I was going to explain why I wanted to use OSB...... cost of metal and extreme hatred of mudding drywall. Then I realized whatever I was thinking regarding the cost of metal I had figured wrong. I can do a metal ceiling for maybe $300 more than OSB, save a lot of painting and labor in general, and have a more attractive (to me at least) finished product. So, that's the way I'm going to go. One access hatch seems to be enough based on the consensus. Gable end is out, not wanting to cut into my exterior.
Thanks for the replies!
Thanks for the replies!
Since you're in NE Ohio, I know that you should have a Menard's fairly close. You might want to wait till they have the next 11% off sale before buying your metal if you get it from them.
A $300 will get ate up pretty quick when it comes to paint. A shop your size will probably take 2 five gallons of Kilz @ two coats before you roll the paint on.