Anyone floored their garage attic?

[In The Ten Ring]

I had wanted to floor mine last summer but I didn't get around to it. Next summer, I want to insulate the attic, run conduit and put in several outlets and a breaker box, and floor the attic. I am planning on using 22/32" plywood.

Anyone floor their attic? What did you use and how thick? Pics?

[_Ogre]

usually if your garage attic didn't have a floor it is not designed to handle the additional load
that's not to say you can sheetrock and insulate it, but the floor and storage up there may be questionable
a typical 25x32 (800sqft) 2 car garage will need 25 sheets of plywood @ 60lb/per sheet = 1500 pounds of weight overhead
then add another 1500 lbs of sheetrock and insulation and you've just added 1.5 tons of weight overhead
and that doesn't include any weight of stored junk overhead
post up a picture of your roof framing

i have a rule; if i have to store it out of sight, i probably don't need it and toss it
i guess i should clarify that... my wife has a rule i have to live by

[dieseldawg142]

if you have engineered trusses, you should be ok. most e.trusses are designed for at least a 4000lb snow load per square (10x10). we regularly load full skids of torch-on (approx 2800lbs) on roofs every day. some bigger houses we will have a couple of skids of torch-on & a couple of skids of base sitting up there. in 32 yrs & thousands of buildings we have NEVER collapsed a roof system.
if your worried, you can always put a lama beam in there to take some load.
if your trusses are on 16" centers, 5/8's is strong & will save a few pounds, if there wider than 16", i would stick with the 3/4.
if your trusses are 2x4, a good option would be to scab some 2x6 or 2x8 on them for your floor

[_Ogre]

your typical engineered trusses are designed to load on the top chord (aka 'roof') of the truss only,
this is why you can load up the top chord with 2800 lbs of materials and equipment
the bottom chord (aka 'ceiling') is not suitable for loads unless specifically designed for the load
if the bottom chord is 2x4 or 2x6 it is not designed for any load other than the building

[dieseldawg142]

yes, the top chord is where the strongest weight rating is, but a big chunk of that weight rating is coming down threw the lateral braces (web runners)onto the bottom cord. if the truss is designed for 4000lb load, around half that will be weighing down on the bottom chord.
800lbs per sq ft is a fairly common number before most trusses bottom chord will collapse. thats a lot of junk in the attic...
i agree a pic is needed, if you have room up there for a room, it's prob. unlikely you have e. trusses

[Cash3481]

I'm no expert but I had my house built and the builder constructed an opening approx...8' deep X 9' tall X 32' long in my garage attic. the Roof is 12/12 pitch and he put down 2 layers of plywood decking. I don't store a lot of heavy stuff up there, just a dozen or so tubs of small parts from trucks I've parted. and a few grills.
He also made a 5'X36" exterior door with fake outer barn style doors on the front of the house. It looks pretty good and if I wanted store a large item I could but I don't want to overload that floor. I have a pic of the house but not the inside of the attic over it. Ill try to take one tonight.

Hers a pic...

[In The Ten Ring]

I'll try and get a pic up of my attic next week.

I don't have trusses in my garage attic. I have an old garage, built in the 1950's(?), and it has the boards meeting in the center of the "A" of the roof and then real 2x6's running across the walls. Walls are of cinderblock.

I am worried about the dead weight of 3/4" plywood but there is a material known as "attic dek" that Lowes carries that is plastic and made for 16" and 24" centers.

I have 24" centers in my attic garage.

Here's a link:

https://www.youtube.com/watch?v=fyAM2XAEnr4

I'll get a pic up of the garage attic and that way you guys can give me more of an informed opinion.

[hard3]

did a web search for floor joist span tables and you will see that 2x6 joists are not rated to span very far. here is a span rating for a 2x6 floor joist.


The Maximum Horizontal Span is:
9 ft. 11 in.
with a minimum bearing length of 0.4 in.
required at each end of the member.
Property Value
Species Southern Pine
Grade Dense Select Structural (pre 6/1/13)
Size 2x6
Modulus of Elasticity (E) 1900000 psi
Bending Strength (Fb) 3105 psi
Bearing Strength (Fcp) 660 psi
Shear Strength (Fv) 175 psi

if you are using engineered trusses , consult the truss manufacturer as to what loading is acceptable. sounds like you have common rafters to a center beam. the horizontal ceiling joists are to keep the walls from pushing out . if they are not webbed to the rafters, then the ceiling would sag/decking applied would exceed the span allowed.

[Cash3481]

Here is a picture of the attic above my garage. Its 8'x8'x 34' from one end to the door. I insulated it to eventually have a non load bearing room for projects inside. I can load large items from the front of the house through the outer barn style doors.
There is 140+ pieces of 2x6 metal backed insulation waiting to go in a barn that isn't built yet so sorry for the packed picture. It is very spacious up there once I get rid of the insulation. It was designed into the house when we built it. I hope it helped you.

[In The Ten Ring]

Originally Posted by Cash3481

Here is a picture of the attic above my garage. Its 8'x8'x 34' from one end to the door. I insulated it to eventually have a non load bearing room for projects inside. I can load large items from the front of the house through the outer barn style doors.
There is 140+ pieces of 2x6 metal backed insulation waiting to go in a barn that isn't built yet so sorry for the packed picture. It is very spacious up here one I get rid of the insulation. It was designed into the house when we built it. I hope it helped you.

Did you forget the pic?

[Cash3481]

Honest officer... It was just there! Lol

[77c10]

When I had my garage built I specified storage trusses. The garage is 24' x 24' and the center section I decked with 3/4" CDX and added a set of pull down steps. Looking back, I wish I had spent the extra $3,000 and had a full room instead of what I have. Oh well, I don't plant to stay there forever and my next one will be built exactly the way I want it.

[dwcsr]

Originally Posted by Cash3481

Honest officer... It was just there! Lol

If Kansas ever legalizes Herb growing your good to go, just hang some lights