Off Topiingc-Subflooring

[Scott D Orbaker]

I am going to be replacing floor joists and flooring in a 14'X 40'building which I will use for storage. No equipment just boxes of household stuff, furniture, etc. I plan on installing 23/32" OSB subfooring but no other flooring over it. Do I still need to leave spacing around the panels and if so, how much? 1/8", 1/16"? I've looked online and found different advice so thought I ask you guys.

Thanks for any help/opinions.

Scott

 

[Stephen Newell]

Wood, even OSB expands and contracts. If it gets damp under the floor you better leave space between the sheets. If it swells up the floor could buckle up at the seams.

 

[Janicholson]

If you live in dry climate, 1/16 will do. If humidity is kinda normal I would go with 1/8. At 1/8 and 4 foot in 40' you have 1-1/4" length gain!
in the 8foot in 40 ' you will gain 5/8" I would probably glue it down tight and make some flexibility in the connection to the foundation. Jim Jim

 

[Loosehandle]

I'd go with 3/4 t&g plywood especially in a shed application

 

[Dennis Minn]

Loosehandle,

I agree. Skip the minimal cost savings and buy plywood. It can occasionally see some moisture without the swell and structural degradation in my experience.

D.

 

[MSD]

3/4 T & G. Try to get fir, not pine. It is way better.

 

[Mule Meat]

Do the smart thing. Spend an extra dollar and install Zip System OSB. Then you will not have to ever worry about water or installing a separate vapor barrier.

 

[showcrop]

Zip sytem is a good product. I would use 3/4 T&G Advantech. The warrantee on that product is phenomenal. The spacing instructions are printed on every sheet.

 

[Stan in Oly, WA]

Scott; I'm glad that five out of seven who have responded to your question so far have advised you to upgrade your plan. That was going to be my suggestion, too, and I didn't really want to be a voice in the wilderness about it. Buying an inferior tool because you're sure you won't need to use it much will make you sorry every time you have to use it, but that's nothing compared to having built a structure to a lower quality than changing circumstances or unforeseen problems make you regret. A 14 X 40 structure should take 17.5 4'X 8' sheets of whatever your use---say 20 if the floor framing is not ideal. Upgrading 20 sheets could be costly enough to make you say "ouch" or not too bad, depending on what you choose.

I'm really "thrifty" (some would use a different word), and I agonize over paying more than I would have to if I took a chance on a lesser product. However, when I take the plunge and pay more for good quality, I'm always glad, and I never regret it later. If you're like that too, go for it. If you've ever found yourself regretting getting good value for paying extra, then I don't know what to tell you.

Stan

 

[kencombs]

If it were mine, the distance from the soil and air circulation would determine whether to use 'normal' OSB or one of the better grades. In my area there is about 10 bucks per sheet premium for Advantech.

 

[c.oawright]

Advan Tech sub flooring. It is water resistant but not completely water proof. It is made like OSB but with different glue and has a higher compression strength. Good stuff.

 

[K Effective]

What's wrong with you guys? Are you all getting soft?!?

The only correct answer is to throw all that household stuff and furniture away and buy more antique tractors to store in that shed!! Leave the floor dirt to absorb all the oil leaks. DONE!

Yeeesh!

 

[Scott D Orbaker]

K Effective

A couple problems with your suggestions. Don't live on a farm so have no old tractors/equipment. The dirt floor of the building is about 2-3 feet below ground level.
Thanks for the ideas though.

 

[Scott D Orbaker]

showcrop

Have you used Advantech? How is it holding up?

 

[showcrop]

(quoted from post at 22:50:05 08/16/20) showcrop

Have you used Advantech? How is it holding up?

I used it two years ago on a new sub floor in my 250 year old post and beam house. It doesn't get wet but that would not be a concern anyway. I became familiar with it when helping on a project 15 years ago. The main point was that it is guaranteed for a year out in the elements with no cover over it as in if your project gets interrupted.

 

[ztrmowers]

osb would not mess with that stuff, use good marine plywood