Joining differently constructed structures

[davejo]

This is probably a dumb question but is there any reason for me not to rigidly join my freestanding addition to the existing pole building?

I built a steel frame barn that is adjacent to and wraps around one side of a pole built shop. I didn't initially tie the two structures together because I didn't want to overload anything in the pole barn. The steel frame barn is self supporting but I need to attach flashing between the two to make things weatherproof.

Should I try to figure out some sort of flexible flashing system that will allow the two buildings to flex and groan independently or just bolt them together and use tradition flashing methods?

The newer building has had a roof on for about a month and had a 6 inch snow load. The footers are about a year old

 

[850xpeps]

The pole barn has poles into the ground? And the steel shop has a slab and footing?

 

[davejo]

Original part is poles in the ground with concrete floor poured after the fact. The "addition" is metal frame on piers, dirt floor.

 

[blkhonda1991]

tons of expansion joint options out there to bridge the gap...its probably going to be pretty ugly trying to get it to work on corrugated siding though

 

[NUTTSGT]

How much freezing and heaving do you have in your location. This may cause you some issues during the winter.

 

[850xpeps]

How much freezing and heaving do you have in your location. This may cause you some issues during the winter.

My thinking as well. Even both kinda having the same concept of piles and poles in the ground is still different enough imo to move differently.

 

[davejo]

I don't think frost heaving is a big concern around here, 24 inch frostline.

I do have strips of Firestone TPO roofing that I could use to bridge the roof gap. Its a membrane but its not very rubbery.
https://www.firestonebpco.com/us-en/roofing/tpo-roofing-systems/ultraply-tpo-roofing-systems

 

[GMCGarage]

This is probably a dumb question but is there any reason for me not to rigidly join my freestanding addition to the existing pole building?

I built a steel frame barn that is adjacent to and wraps around one side of a pole built shop. I didn't initially tie the two structures together because I didn't want to overload anything in the pole barn. The steel frame barn is self supporting but I need to attach flashing between the two to make things weatherproof.

Should I try to figure out some sort of flexible flashing system that will allow the two buildings to flex and groan independently or just bolt them together and use tradition flashing methods?

The newer building has had a roof on for about a month and had a 6 inch snow load. The footers are about a year old

Flexible - different materials, different geometry, different movement.

 

[CraigStu]

Do they make those plastic inserts that match the metal siding?
https://www.homedepot.com/p/Suntuf-24-in-Horizontal-Plastic-Closure-Strips-6-Pack-92770/100067957
I know these are usually used under roofing but maybe they could be used w/ careful caulking and a treated or composite 1x2 so you now have a flat surface to attach your TPO seal to.

 

[davejo]

Ok so with respect to wind movement. One structure is stiffer than the other. If I bolt them together, now both structures have a different amount of stiffness at the joined ends in comparison to the free ends.

Wouldn't this be the same scenario as if you were to build a mezzanine or enclosed room inside an otherwise freestanding shop building? Your internal framing makes that end stiffer than the freespan space at the other end of the building.

This is sort of interesting in an academic way. I might rig up a pencil and paper interface to see how much movement there is between the two sections. Redneck seismograph?