# Anyone knows how to install attic flooring?



## lybrian1 (Aug 10, 2010)

i have a big attic space which i would like to put in some flooring so that i can store some boxes up there. its a new house (5 years old) so there seems to be 2x4 beams running along the house. what can i use as flooring? a sheet of plywood is too big to fit through the attic opening


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## Jackson (Jan 30, 2009)

You can buy planks from the lubber yard that you can get cut to size and lay them down side by side. You can get them about 2"-3" thick. They are very strong.


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## poobar (Feb 20, 2011)

The main issue you have is the beams in the attic.

Being from the UK, this is something that happens quite oftern. If the beams of your attic are strong enough, the just buy 3/4 inch 8'x4' plywood and rip it to a size that fits the beams and will go up the hole to your attic.

The question is really, what are you using the space for. If you want to do anything serious up there with multiple people then you will need to reinforce the beams. If it's just you and a couple of boxes, then whats there already will be fine.


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## 50seven (Feb 14, 2010)

Yeah use planks like 2x6's or 2x8's; or cut strips of 3/4" plywood; cut to lenght so that they span the space between the trusses but will still fit through the attic access hole. Butt them up end to end to make longer lengths.

The main thing to watch is that you don't squish your attic insulation. You may have to build up the trusses so that your planks will clear the insulation without squishing it.



poobar said:


> The main issue you have is the beams in the attic.
> 
> Being from the UK, this is something that happens quite oftern. If the beams of your attic are strong enough, the just buy 3/4 inch 8'x4' plywood and rip it to a size that fits the beams and will go up the hole to your attic.
> 
> The question is really, what are you using the space for. If you want to do anything serious up there with multiple people then you will need to reinforce the beams. If it's just you and a couple of boxes, then whats there already will be fine.


I wouldn't worry about the weight- engineered trusses are quite strong, and unless you plan on having parties up there or storing all your barbells and 200 years of back-issue National Geographics up there, you'll be fine.


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## lybrian1 (Aug 10, 2010)

i dont plan to put anything heavy at all. just a few boxes of clothes
it will not be intended for living space.
i was thinking of getting 2x4's and spacing them out a bit but i am worry about the weight of the 2x4's on the beams


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## lybrian1 (Aug 10, 2010)

what is the issue with squishing the insulation? 


50seven said:


> Yeah use planks like 2x6's or 2x8's; or cut strips of 3/4" plywood; cut to lenght so that they span the space between the trusses but will still fit through the attic access hole. Butt them up end to end to make longer lengths.
> 
> The main thing to watch is that you don't squish your attic insulation. You may have to build up the trusses so that your planks will clear the insulation without squishing it.
> 
> I wouldn't worry about the weight- engineered trusses are quite strong, and unless you plan on having parties up there or storing all your barbells and 200 years of back-issue National Geographics up there, you'll be fine.


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## Riceburner (Mar 14, 2008)

squishing the insulation defeats it's purpose. You don't need 2x4s. The beams are probably 16" apart. 3/4" plywood strips as wide as you can fit thru the hole....across the beams would be fine for walking on and storing boxes. Keep in mind that it will be cold or hot or humid up there, depending on the time of year. And be aware of any animals that may make it in....those clothes will make a nice nest.


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## lybrian1 (Aug 10, 2010)

Riceburner said:


> squishing the insulation defeats it's purpose. You don't need 2x4s. The beams are probably 16" apart. 3/4" plywood strips as wide as you can fit thru the hole....across the beams would be fine for walking on and storing boxes. Keep in mind that it will be cold or hot or humid up there, depending on the time of year. And be aware of any animals that may make it in....those clothes will make a nice nest.


i will do that
i plan to put my stuff in plastic bins up there. i really need to storage space


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## mrobson (Mar 5, 2011)

i would recommend planks, try to get the from a lumber yard if its just for storage use rough wood as nice 2x4's are expensive these days. Also you probably wont need thick wood if all your storing is boxes.


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## 50seven (Feb 14, 2010)

Don't worry about the weight. 5/8" plywood is strong enough - it's what your floor is made of, with the same joist spacing of 16"; if your trusses are spaced at 24" then use 3/4" plywood.

Squishing the insulation dramatically reduces the insulating capability. Use a 2x6 or similar on end to increase the height of the trusses. If you understand what I'm describing...


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## lybrian1 (Aug 10, 2010)

ok i appreciate all the help but i am lacking the details in the project.
can some one telling what i should do and give me some detail instructions please? one thing i am unsure about is how to not squish the insulation


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## Riceburner (Mar 14, 2008)

Depends on if the joists are exposed or covered in insulation.

If exposed, 








just lay sheeting across the joists and screw them down at the corners.

If the joists are not exposed, 








you will want to add some material to the top of the joists to get above the insulation. That may be the tricky part if you're not handy.

also, if you are going to be up there any length of time use a mask. Or create a complete floor to get away from the insulation...depending on what it is.


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## lybrian1 (Aug 10, 2010)

my attic is a bit different. its the shreds of white cotton-like things. so the joists are kind of covered but they can be exposed too.


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## 50seven (Feb 14, 2010)

lybrian1 said:


> my attic is a bit different. its the shreds of white cotton-like things. so the joists are kind of covered but they can be exposed too.


Good. That is better insulation. But you'll still need to leave if fluffed up. Try something like this:


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## lybrian1 (Aug 10, 2010)

thanks for the picture, it really cleared things up. how should i attach the 2x6 or 2x8 to the old joists?


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## Riceburner (Mar 14, 2008)

easiest is to screw in metal strapping/plates to hold it in place.


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## 50seven (Feb 14, 2010)

lybrian1 said:


> thanks for the picture, it really cleared things up. how should i attach the 2x6 or 2x8 to the old joists?


Toenail it, but use screws.










Or you could use a metal plate thingy (i can't for the life of me remember the proper name) - it's the flat thing in this picture:










But personally I'd just toenail in a screw every 12" or so. If you've never toenailed before, it just takes a bit of practice to get the angles right. I use 3" deck screws or my Paslode cordless framing nailer.


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## lybrian1 (Aug 10, 2010)

thanks, the project is becoming more expensive then i thought


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## Riceburner (Mar 14, 2008)

or truss plates








but they need to be hammered

You could always skip alternate beams

or connector plates


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## lybrian1 (Aug 10, 2010)

jeez how much would you say it would cost to cover a 20ftx20ft section? in materials alone?


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## Riceburner (Mar 14, 2008)

depends on materials. Or go to a new housing development and get scrap sheeting from the waste piles. Built a few shelves that way when my area was built.


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## 50seven (Feb 14, 2010)

3/4" plywood: $26
8' long 2x6: $4.50
works out to about $44 to cover a 4x8 foot area = $1.38 per square foot
20x20 feet = 400 sq. ft. = $550
plus a good sized box of 3" and 1 1/4" deck screws at about $20 ea. (I buy them by the case so this is a guess)
plus tax and other stuff, you're already up to at least 670 bucks in basic materials. 

Riceburner's idea of scavenging is sounding real good about now...


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## lybrian1 (Aug 10, 2010)

now im not even sure if i want to go through with it


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## Riceburner (Mar 14, 2008)

gets lots of skids and tear them apart....


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## lybrian1 (Aug 10, 2010)

i think i can get away with using 2x4's to raise the flooring and plywood on top
there is a big price gap between 2x4's and 2x6's


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