You need to have this building evaluated by a structural engineer, including footing sizes. Most pole structures are agricultural buildings that don’t fall under any state codes or are exempted from structural design parameters.

I don't know what you have or how it's built to confirm or determine weight load. Some pictures of what you have would be helpful because your Idea of a pole barn and mine may be built two entirely different things.

The international Building code, chapter 5 floors gives tables for the live and dead loads for species and grade of lumber based on length, spacing and size and would be a good start to confirm weight load for your floor joists.

The roof would have no bearing on the floor because a standard pole barn sets the roof trusses directly on the poles transferring the weight to the footings, or on truss carriers attached to the poles. How your pole barn is built would determine if you would need to beef up the truss carriers to support the added floor joists. I just don't know what you have.

"is there anything that I'm missing in my implementation plan?"

A local structural engineer.

Prepare for the worst.

Ok, you people are nuts thinking every little project, including this common addition to a pole barn needs a frickin structural engineer! The IBC is designed to remove the need for an engineer in most common building practices because the engineering data is published to use based on safety. He's not building a sky scraper and this Idea everyone should hire an engineer, and is repeated constantly on this forum tells me most here have NO clue what they are doing, talking about or experience to back up their advice.

@outpaientzero True, he should proceed with loading the bottom chord of his truss with excessive loads. It will help him appreciate how deflection causes roof leaks in an exposed fastner steel roof. Plus he will enjoy how his ridgeline is happier, smiling all the time.

From what I can picture from your verbage, your 9x8 space surely isn't from one side of the pole barn to the other. So being that is the clear space between the web chords, you cannot just sister deeper 9' or 8' long joists to the bottom chord in the middle of the trusses just for that 9x8 platform. If you want an uninterrupted floor below, the new floor joists would have to extend across the whole 24' or whatever the barn width is to new post support and footings at the outer walls. Or, if you don't mind columns below, you can just build a 9x8 platform that doesn't interact with the trusses, but has 4 posts unto itself.

Except you said "scissor," which refers to the ceiling being sloped; it will be hard to keep storage from sliding if you follow that slope.

You're getting the trusses from a good source to ask these questions. They can figure what they would recommend for your application. Some pole barn construction, like R & R Building on YouTube Link. He has installed sheet metal for the bottom side as a finished ceiling. And then blown in insulation..

I have considerable experience with pole structure design, construction and failure. In my area, most major pole structure suppliers provide roof trusses with a total roof, snow and wind load rating of 28 psf. The IRC and IBC codes in my area require a minimum of 35 psf just for snow load. Add in roof loads and wind loads and they should be designed to a minimum of 49 psi with no ceiling attached. Any load applied to a failing truss will be a complete failure.

Correction: 49 psf

@3onthetree hit it right on the nuts and was a great comment. I wanted to see what the OP is working with and never suggested hanging a storage loaf from the trusses but @D B thinks the sky is falling.

@Julie Praus and @Mark Bischak, Architect your comments to consult an engineer isn't what the guy asked for so why give an answer without a reason. If you're both so experienced and knowledgeable it's certainly not evident in your comments.

@dan1888 commented asking a pole building contractor is good, but I would add any experienced framing carpenter could suggest a correct solution in two blinks of the eye.

I had the same ideas as @3onthetree but asked for more info and would of helped him out. But I'm done with this thread and will just wait for others without a clue chime in with the catch all phrase used "hire a structural engineer" when one isn't needed or requested.

"your comments to consult an engineer isn't what the guy asked for so why give an answer without a reason."

Au contraire, it is what he asked for ("I appreciate your help and guidance!" (emphasis added)) and it is what he needs to hear in the best interest of his health, safety, and well being. Such an endeavor will require a permit and the building inspector will require a stamp on the drawings by the design professional.

If the OP lives in an area where there is no building requirements, he can take your advice and the building can possibly fail where the OP will fall to his death and be eaten by a bear.

I am sure the OP will apply any guidance they see fit.

Typically pole barn trusses are designed and built to the very bare code minimum, probably 5 pounds/square foot dead load on the bottom chord of the truss, maybe 10 if you're lucky. You'd be very fortunate if the trusses could carry the dead load of the floor system, much less the live load of stored stuff and people.

Pole barns only have a superficial resemblance to a legally habitable structure. They end up costing you way more than building a basic low spec home, because nothing about them meets code for a residence. Every single part has to be upgraded.

Our ancestors would build the barn first and better than their homes. A pole barn costs about $25 to $35 per square foot and a fraction the price of a spec home so who are you lying to Verbo.

It does seem the word Pro is loosely used on houzz.

Sorry Zach, your thread and question has been hijacked.

@outpaientzero The last two pole barn houses I quoted were cheaper when built as standard stick frame. We still used steel on the exteriors, just stick framed instead of pole building. The only exception is when you have really tall wall heights (14' ect). Then they seem to be cheaper with poles. These spaces feel ridiculous though and I do all I can to talk the client out of the crazy height.

Somehow it seems the "Pros" on this site have lots of time to burn running off people with valid questions. Is it because they've run off all of their potential clients, also? I mean, how abrasive can a person get?

Is 'contact a local structural engineer' bad advice?

My main question is to confirm if adding these floors will effect the structural integrity of the building in any way? Yes, it has the potential to cause structural issues.

Is there a way to figure out the maximum weight load this new floor could hold? Yes, I think that truss design companies, engineers, or other similar such folks could calculate that for you.

Additionally, is there anything that I'm missing in my implementation plan? Well, having been in a number of pole barns.... Generally, in my area, they are built only to shelter tractors and implements and hold up snow. Thus, I would wonder if the walls and foundation would carry the loads properly.

"Is 'contact a local structural engineer' bad advice?"

Yes, it's bad advice. Might as well tell the OP to pile up a stack of $100 bills and set fire to them. Not every response has to be "Hire an architect" or "Hire an engineer".

Local structural engineer and pole barn are rarely found in the same neighborhood

"Yes, it's bad advice."

There has been some miscomprehension recently, so I will repeat my previous comment. For those that did comprehend the previous comment, I apologize for the repetition.

Au contraire, it is what he asked for ("I appreciate your help and guidance!" (emphasis added)) and it is what he needs to hear in the best interest of his health, safety, and well being. Such an endeavor will require a permit and the building inspector will require a stamp on the drawings by the design professional.

If the OP lives in an area where there is no building requirements, he can take your advice and the building can possibly fail where the OP will fall to his death and be eaten by a bear.

In my small rural farming town we have an engineer that will do this for less than $1k. Your local lumberyard or local builders may know someone of similar value.

The big issue is the total misinterpretation of a trussed roof structure as equating to an ”attic”. It isn’t anything close to an attic, despite being lots of wasted space due to the farmer barbie built paper doll level support of low level quality pole barn trusses.

It’s a pretend living structure for broke posers. Or a good place for your tractor or hogs to stay out of the rain. It has only superficial resemblance to the requirements for a human shelter with an attic. Only the siding would work for that, and metal is still way more expensive than basic vinyl for that.

The ”attic” certainly is no attic, and can not be made into one. It can’t even be made into additional agricultural storage without a lot of added on work that has nothing to do with altering the trusses. To take advantage of the vertical, it it requires interior framing, with a genuine foundation for the loads, and a second floor platform and code legal stairs.

"farmer barbie built paper doll level support of low level quality pole barn trusses."

So you think a farmer would store farm machinery worth millions under low quality construction? LOL. An equestrian facility 4 miles from me spared no expense building their pole barns (5) for their own horses and others and many thoroughbreds exceed $100K in price. Yep just a bunch of broke posers living around me.

I and twelve others live on 160 acres zoned Rural reserve surrounded by subdivisions in a suburb 15 miles from Minneapolis. We've ran off developers over the years wanting our land with huge offers and we refused. We like our land along with our pole barns which are code exempt so we can do as we please, and believe you can take that code and shove it. None of my stereotyped poor rural neighbors live in pole barns or call themselves pros, and don't believe anyone mentioned living in a pole barn. But the OP's 8' x 9' space in his pole barn can certainly be turned into a storage loft will minimal expense or effort.

The only exempt buildings in Minnesota are Ag buildings. To qualify as an Ag building, it needs to pass three requirements. 1. Must be built on agricultural zoned property. 2. Must be used to house livestock, Ag equipment, Ag feed or products. 3. Owner must show an income from Ag businesses on the property. If you don’t pass those three requirements, you are not exempt. It is possible to build pole structures to code if the supplier is asked to design them that way. We have a pole structure that meets the Minnesota Building Code and I sleep well at night knowing that if a sever storm or unusual snow fall collapses the roof, my insurance company has no loop hole to deny coverage of my non-ag toys.

They don't get snow in Minnesota.

So Julle, where did you dig up that pile of misinformation? Minnesota state code

326B.121 STATE BUILDING CODE; APPLICATION AND ENFORCEMENT.

(c) The State Building Code does not apply to agricultural buildings except: 326B.36 which is for INSPECTION of electrical only.

Many counties do have some basic minimum requirements and all differ addressing truss and foundation specs with and without inspections, but none has a thing to force Zack to comply when making a loft in his barn if he lived in Minnesota.

Not one plugged nickel needs generated from Ag income to be exempt from state code, and insurance companies do cover damage. I know this as fact when every pole barn in the area had all the sheet metal replaced from hail 4 yrs ago and all covered by insurance. I have the metal from 3 piled in the back.

What makes you think the OP's pole barn is agricultural?

Kevin 9408, you need to define an ag building before you can exempt it. See MN statute 326B.103 and follow all tracking and history and you will find my info. My colleagues and I have spent endless hours educating jurisdictions on these rules and requirements, you are not alone in your misunderstanding of the interpretations and applications of the Building Code.
I wish those who boldly and proudly advocate for ignoring the code would be equally bold in disclosing their non-compliant modifications when they sell their property. It would eliminate a large portion of the questions asked on this forum.
To continue this discussion with this op is pointless since he’s probably not from Minnesota and has not given any feedback. Hopefully whatever he does is safe.