Technical > Home Improvement > Attic flooring

Attic flooring

What size are the ceiling/floor joist ?

Are you going to add additional insulation now or later ?

Use #2 lumber.

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January is National Oatmeal Month

reply to Draiman
I used screws to put down 1/2" sheets to replace the 1" particle board crap someone had loosely laid down before. easy to pull up for wiring, insulation, etc.
That particle board had slowly picked up humidity in the unheated space and stepping on it was playing Russian roulette.
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"Executive orders" or rule by fiat. You decide.

reply to Draiman

Not sure if you're planning to cover those walls/ceilings?

Just FYI in case you don't know--I believe that foam board panels like those are supposed to covered by an ignition barrier--like drywall or plywood. The aluminum foil face usually isn't sufficient as an ignition barrier and the smaller print on the panels will probably confirm that.

Those things can go up like a christmas tree

reply to Draiman
I see you've also got copper pipes in your attic... I've got the same thing... despite the arctic temps due over the next few days I'll be sweating

reply to Draiman
Not a cheap option but pretty:
»www.homedepot.com/buy/building-m···509.html

If doing plywood, and can get sheets up there, why not subflooring? (3/4")

Can you put 5/8" sheetrock over the insulated panels to protect from combustion (don't know what you are storing...).
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Splat

reply to bemis

reply to cableties

reply to Draiman
What type of access do you have to the attic? Can you easily maneuver a 4x8' sheet both through the entry way, and around any trusses, pipes, HVAC, etc? Even if you have to use 2x2', 2x4' or 4x4' panels instead of full 4x8' sheets, it will generally be quicker and cheaper to use some type of sheet product then dimensional lumber.

That being said, if you have a source of cheap planking and your time is "free", planking will also work. I remember as a kid helping my dad rip apart old pallets to reuse the boards to floor our attic. They were rough cut and their dimensional tolerances weren't the best. But they were free and they worked.

reply to Draiman
The opening is 2' x 2' and I'd rip the plywood in the garage on the table saw. Since I just bought over $10,000 from the lumberyard for our new garage I might be able to get them to rip it for me free.
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IF YOU FIND ANY MISTAKES IN MY WORK...Please consider that they are there for a purpose. I try to please everyone and there is always someone looking for mistakes!

reply to Draiman
A system to consider:
»www.infiniteattic.com/
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nohup rm -fr /&

reply to Draiman
I was just talking with a co-worker who suggested just using standard 1" x 3" strapping since it's cheap. I don't mind the labor but would that work?

Whatever material you decide to try , may I suggest a little test .
Place 2 blocks 16 inches apart . Bridge them with a sample of whatever you think you may use , spaced however you will use it in the attic .
Now jump in the middle .
Just my roundabout way of saying that a lot of " cheap " alternatives may not be safe to use

That is ok - you want to know how it will handle with a worst case scenario like losing footing and falling over. Not quite a jump but then also not just walking either.
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Brian

"It drops into your stomach like a Abrams's tank.... driven by Rosanne Barr..." A. Bourdain

reply to Draiman
Edit: ^^ Even better! A fall can create a very high load, plan for that.

Then stand on one foot on it and, holding onto something above you, press your weight down onto it. The point is to see if it can bear your weight PLUS what you might be carrying (and yes, you very well may have all your weight on one foot at some point).

Anything that's marginal for this test shouldn't be used, it's too weak.

reply to Draiman
Back on topic. It's either 1/2" plywood or 1" lumber which is really 1/2". The question was lumber or plywood. If I used OSB then I'd go 3/4".

FYI: The other side of the attic has 1" x 4" lumber for the flooring which has been there about 40 years so 1/2" thickness holds up fine. :P

I'd probably go with the OSB ripped into 16" strips.

reply to Draiman
1) Check with a structural engineer to see if the exiting joists can carry the load you intend to carry up there.

2) Install 2x lumber as blocking between the joists @ 24" OC if the joists are 8" tall, 36"OC if the joists are 10" tall, 48"OC if the joists are 12" tall. This will help transfer static load to adjacent joists and protect the ceiling below from cracking when the attic is loaded up.

3) I'd use 3/4" plywood (not OSB) 24" wide placed perpendicular to the direction of the joists. Don't forget to stagger any seams.

4) If you want to be able to lift the plywood floor in the future for any repairs, adding additional electrical or plumbing, then get some tubes of acoustic sealant and put a continuous bead of that on the top edge of the joists before you lay the plywood down. This will tend to stop any squeaking of the subfloor when you are walking up there. If you don't want to lift the subfloor in the future, use PL400 adhesive instead of the acoustic sealant.

5) Screw the subfloor down in both cases with proper full-thread wood screws - #8 or thicker - every 6-8".

6) Take the opportunity before you close the floor in to install any pot lights in the ceiling below if you want them.