What thickness flooring for shop loft

[woodlandfarms]

We are talking about adding a shop loft in one of the bays of the shop. this would be to create a second story... Right now it is a 24X45 dimension, with abit taken up by a stairwell. Looking at the math, we are looking at 14" I Beams (wood) 16 OC. I am thinking 3/4 would be enough but a friend said 1 1/8. Halfwould be office space and half would be storage. Nothing grossly heavy but not 16 rolls of toilet paper either.

 

[RNeumann]

1 1/8” is a very high quality subfloor. With 16” OC joists, 3/4” t&g glued and fastened plywood or OSB would be just fine. Their is nothing wrong with 1 1/8” though.....but every house I’ve built for myself has 3/4”

 

[4570Man]

I don’t see anything wrong with 3/4. Without piecing together layers I don’t even know where to get 1-1/8.

 

[mddorange]

Like what has been stated above, 3/4" is what is code in most places. If you knew in advance that it would be supporting very heavy weight, then 1 1/8" might be called for.

 

[CADplans]

I have two mezzanines in my shop,,
one floor is 3/4" hardwood boards, the other is 3/4 inch poplar boards, topped with 3/4" T&G oak flooring.
the single board floor is strong, but, it is like walking on a "sponge", it is on 24" OC steel beams.
the double floor is like walking on concrete.

The double floor is setting on 8X12 beams 4 feet on center,,
Even with the 4 foot center spacing, the floor is solid.

 

[4570Man]

3/4 advantec is pretty solid on 16” centers. Another 3/4 layer does firm it up though. It would be about $1000 to cover that in 3/4 plywood at local pricing so I personally wouldn’t double it.

 

[RickB]

Whatever you decide, use two layers and split the seams to get the thickness you want.

 

[BLSXJ]

if you can source ungraded lumber, putting down 1.5" rough sawn planks might be a decent option.

 

[countrybumpkin]

On mine I have 16” centers and 3/4 osb t&g, it’s plenty sturdy for my uses, but I don’t use it daily, just for storage. If I was using it as a office and such, I’d cover the osb subfloor with a laminate or something to take wear and tear and to be able to keep clean.

 

[EddieWalker]

What type of flooring are you going to put over the sub floor? If it's anything besides tile, you will be fine with 3/4 T&G

Assuming that your joists are sized correctly for the span, then 3/4 is overkill for 16 inches. Most houses have 3/4 T&G plywood on 24 inches. The 1 1/8's is crazy heavy to handle and install. It's really nice once installed, but I rarely use it because of it's weight, price and lack of need for that much additional stiffness. More importantly, don't forget the glue!!!! Nothing worse then a squeaky sub floor after it's all said and done.