Can I do this in my attic for storage?

[aragno]

I have an area of 88” x 55” I would like to use for holiday decoration storage.

Here is a photo.

My thought was to add 2x4s where you see red lines and secure 1/2”-3/4” plywood over the top.

I was going to lay down some insulation and leave some air space between the decking and the insulation. I could leave a 1/2”-1” gap on ends of decking to aid in circulation if that is advisable.

This area is above my garage.

There is an additional area beyond this space (in the background) that I would also like to make for storage but would be for lighter weight items as it is a bit difficult to access. That area and modification can be seen in second photo with green lines. These are on 24” centers so if my load is light, perhaps I can just ignore the 2x4”s in between existing ones. Existing pink ones are attached to roof on the far right. These are not prefab trusses. (Ignore the old light fixtures I found stored up there).

Let me know if this seems okay, etc.

 

[Old Man Roger]

Half inch is pretty thin for a 24 inch span, I would think just walking on it might make it flex quite a bit.

Another thing to think of, if you put any bracing between the rafters, make sure they fit snug. You don’t want the rafter to move or twist when you screw the brace in. It might crack the drywall on the ceiling below.

 

[aragno]

Half inch is pretty thin for a 24 inch span, I would think just walking on it might make it flex quite a bit.

Another thing to think of, if you put any bracing between the rafters, make sure they fit snug. You don’t want the rafter to move or twist when you screw the brace in. It might crack the drywall on the ceiling below.

I had the same thought. I haven’t looked at the total weight differential between 3/4” and 1/2” + additional 2x4 bracing.

Would 3/4” flex less?

 

[Old Man Roger]

I had the same thought. I haven’t looked at the total weight differential between 3/4” and 1/2” + additional 2x4 bracing.

Would 3/4” flex less?

Usually when it comes to plywood, the thicker the stiffer.

 

[jpaw]

I'm walking around on 7/16". It's not like I'm jumping or storing heavy concentrated loads on it.

 

[Walkers]

I wouldn’t have any issues with doing that. I’m sure somebody here will object because the engineering wasn’t designed for that, but I doubt you will have any trouble.

 

[Old Man Roger]

I'm walking around on 7/16". It's not like I'm jumping or storing heavy concentrated loads on it.

24 or 16 inch span?

 

[jpaw]

24 or 16 inch span?

24"
Yes there's some spring to it but once it's fastened down it's not bad.
Most roofs are 7/16" or 1/2" with clips and are fine for snow loads.

 

[mike93lx]

23/32 is rated for 24oc as subfloor. 7/16 is plenty for storing decorations

 

[Old Man Roger]

24"
Yes there's some spring to it but once it's fastened down it's not bad.
Most roofs are 7/16" or 1/2" with clips and are fine for snow loads.

I wasn’t thinking he would fall through or anything. I was just thinking it might flex enough to rock the rafter enough to cause issues with the drywall on the ceiling.

 

[jpaw]

I wasn’t thinking he would fall through or anything. I was just thinking it might flex enough to rock the rafter enough to cause issues with the drywall on the ceiling.

I have osb on my ceiling so I had no worries. We walk around in our attics stepping on the rafters without issues so securing a large sheet would only reduce the flex.

 

[aragno]

24"
Yes there's some spring to it but once it's fastened down it's not bad.
Most roofs are 7/16" or 1/2" with clips and are fine for snow loads.

Are nails preferred over screws? Or screws sufficient?

Any idea on suitable insulation to lay in there? Remainder of house has blown in insulation but I need a DIY solution.

 

[aragno]

Half inch is pretty thin for a 24 inch span, I would think just walking on it might make it flex quite a bit.

Another thing to think of, if you put any bracing between the rafters, make sure they fit snug. You don’t want the rafter to move or twist when you screw the brace in. It might crack the drywall on the ceiling below.

This is a sound consideration.

 

[jpaw]

I use drywall screws so

Are nails preferred over screws? Or screws sufficient?

Any idea on suitable insulation to lay in there? Remainder of house has blown in insulation but I need a DIY solution.

I use drywall screws so I can pull them up if I need too.
I had 2x6 so I just used r19 but you could use blown in if you like.

 

[Old Man Roger]

Yup, I used screws so I could access the plumbing.

 

[theoldwizard1]

Figure the weight of your decorations. 1/2" is probably adequate. Add more joists (16" O.C.) of be careful that you only step on the joists.

 

[mike93lx]

I would use screws, but definitely not drywall. They are brittle and good only for hanging drywall.

 

[aragno]

I would use screws, but definitely not drywall. They are brittle and good only for hanging drywall.

I was thinking to use some SS316 screws.

 

[aragno]

Figure the weight of your decorations. 1/2" is probably adequate. Add more joists (16" O.C.) of be careful that you only step on the joists.

I will mark the joists anyway, regardless of what spacing is ultimately used.

 

[aragno]

I use drywall screws so

I use drywall screws so I can pull them up if I need too.
I had 2x6 so I just used r19 but you could use blown in if you like.

I think i will see what Home Depot has. If I start to put insulation over the entire garage area, will it make a noticeable difference?

How do I select an appropriate R factor?

 

[LSU]

I did 1/2". I wish I'd use thicker plywood. this was about 20+ years ago.

I used a finishing nail gun to put mine down and then screwed them in place.

 

[mike93lx]

I was thinking to use some SS316 screws.

Excessive, but whatever floats your boat.

I keep a box of 1.5" spax construction screws around for stuff like this.

 

[Wrench97]

Screws if you don't have a nail gun, hammering nails in will cause nail pops on the ceiling below.

 

[Old Man Roger]

I would use screws, but definitely not drywall. They are brittle and good only for hanging drywall.

I got some deck screws on clearance for pennies on the dollar, but I wouldn’t hesitate to use drywall screws if that’s what I had.

This isn’t anything structural, it’s not like there would be any type of racking load. They’re just going to keep a piece of plywood from sliding around.

I do agree that it’s probably not a great idea to use drywall screws for any additional rafters or added supports though.

 

[mike93lx]

I got some deck screws on clearance for pennies on the dollar, but I wouldn’t hesitate to use drywall screws if that’s what I had.

This isn’t anything structural, it’s not like there would be any type of racking load. They’re just going to keep a piece of plywood from sliding around.

It's not entirely an issue of not breaking in place. You're likely to pop the head off when fastening into material harder than drywall

 

[Old Man Roger]

It's not entirely an issue of not breaking in place. You're likely to pop the head off when fastening into material harder than drywall

Ya, been there done that with some osb. Never had any issues with using them on regular plywood and 2x4’s though.

 

[CraigStu]

Grab a piece of the 1/2 osb, lay two 2x4s on the floor 2ft apart. Lay the osb on them. Walk between the 2x4s. I think this test will show you that 1/2in is fine. This doesn't need to support three 200# people walking on it. Just needs to support your decorations. Put them in plastic tubs so they slide easily on the osb. Make up a 'T' pusher/puller from 2x2s so you can push the further tubs away for storage and then back toward you and you never even need to walk there. On the first pic I'd ad a 2x4 to the 2x10 (Guessing) on each side so the plywood has something to sit on the same height as the existing 2x6s. I can't tell what is on the edge of your space that is closest to the camera for sure but it looks to me like your plywood will be captured between the 2x10s. If that is the case drop your plywood in there and put 2 screws in it

 

[Alchase]

When I moved into my new house in 2015, it had the attic above the middle bay already covered in 3/4” ply. I asked the builder if it was ok to do the other two bays the same.
He said there was no problem at all.
My only issue was now that it was closed up except for the ladder access, I had to cut the 3/4” sheets to 2” in width to get them through the ladder hatch. I used screws to attach. Has been great for storage.

 

[brownbagg]

all the weight is on the joist hangers