Floor joist spacing question

[Bo Montague]

Hello folks, new here and couldn’t find an answer in the search. I’m building a 20x26 shop, wood floor, 2x10 PT floor joists with 1 1/8” advantech flooring. Max span of 2x10’s is 9’6”. Load will be of a typical wood working shop, heaviest items will be a lathe and table saw. Floor will be beefed up under the lathe.

Here’s my question. Will the floor joists 24” OC be sturdy enough?

Thanks, Bo

[Matt Day]

I bet a structural engineer would know. Do you want a bunch of armchair woodworkers telling you the spacing or an engineer who will know what the inspector is going to be looking for?

[Paul Lawrence]

... Do you want a bunch of armchair woodworkers telling you the spacing or an engineer who will know what the inspector is going to be looking for?

Hey! I resemble that remark!

What are these 2x10s sitting on? You can decrease the span distance by putting a support in the middle, for instance.

There are plenty of tables on span distances for various size lumber available to a search.

[Scott Winners]

I am not an engineer. I have been on two different 2x10 floors. One with single layer TG 3/4 ply subfloor and 24" joist spacing, the other 16" joist spacing with two layers of 3/4" not tongue and groove.

both met code, the 16 center floor was a LOT stiffer.

I have never heard of advantech flooring before.

How much, while we are waiting for a structural engineer to come along, are you willing to have your floor bounce?

[Tom M King]

I wouldn't try to save a couple of hundred dollars by using 24", instead of 16".

[Tony Pisano]

I agree with the shorter span. You never know what fantastic deal you might get on a heavy piece of equipment in the future.

[Von Bickley]

I don't like 24" centers on rafters, studs or floor joists. I would spend the extra money and go 16" on center.

[Bo Montague]

Thanks for the response guys!
Matt - I’m sure a SE would know the answer, he’d also like a big check for the answer.
Paul - I’ve read span tables until my eyes blead, they say it can be done, was checking to see if anyone else had experience.
Scott - it’s good stuff, check it out http://www.huberwood.com/advantech/p...ntech-flooring
Tom - gotta save the money for that next piece of equipment
Tony - winning response! Never know when that deal will happen.
Von - gonna spend the extra for 16OC

Thanks again guys!

[Paolo Trevisan]

well... I am a SE and here is what I would do.
run a beam at mid span so now your joists are only running 10'
place joist @ 16 IN c/c. last thing you want is vibration on your floor.
with running machines you will get some vibration. yiu want your floor as stiff as possible.
3/4 in subflooring or EQ.
insulation between joists. and possibly run your dust collection ducting there as well.
you will not regret it. with lumber pricing as it is skimping to save 50 bucks isnt worth the potential issues later.

cheers. and enjoy the build.

lastly keep in mind the span span rating for the joists you are seeing is possibly not what the loading is for a shop floor.

p

[Lee Schierer]

Your cost difference will be about 12 joists for the 16 OC floor. The benefit is a much stiffer floor. You might also want to consider 2 x12's for your almost 10 foot span.

[Tony Latham]

I can't answer your joist question but I'm sipping coffee over the same Advantech subfloor. It's great stuff. Stiff.

You might also look at BCI engineered joists. They may be cheaper. https://www.bc.com/manufacturing/bci-joists/

For whatever reason, my house architect and contractor both agreed on them.

T

[Jim Becker]

I agree about looking at the engineered I-joists. My shop building was build with them in the ceiling of the first floor and the upper level is rock steady, even with just a layer of 3/4" plywood. (12" I-joists, 16" OC) I would imagine them combined with the Advantech would provide a shop floor you couldn't move with anything less than an earthquake.

[Todd Mason-Darnell]

You should be fine.

Max span, per the American Wood Council span calculator, is 15' 2"

https://www.awc.org/codes-standards/...tware/spancalc

That being said, I would go 16" OC for the stiffness.

[Jon Snider]

My floor in my shop in progress is 40 x 28’, with an approx 32’ metal I beam spanning the length down the middle on two 6’ concrete buttress walls, also sitting on two metal columns equidistant from buttresses.

The engineered floor I joists are 3” x 11 7/8” on 12” center, supported in the center by the metal beam. Wood flooring is 1.125” Advantech T&G.

This is was designed by an engineer after I gave him weights for some of my heaviest machines (up to 2500#) and locations. And then I told him I wanted to sleep better at night. Probably major overbuild but better than a collapsed floor for not a whole lot more money.

If I ever sell the house, I can probably call it a garage and park cars on it too.

Jon

[David M Peters]

Bo, can you describe your reinforced floor area for your lathe?

Some day I would also like to have a wood-floored shop but would almost want a separate concrete pad for my AB!