Extra supports, how do I determine if I can remove them?

[travisn1]

The barn is about 15 years old, I've been here since July.

The 2x4s look like they were to keep the rafters from tipping over before the roof was done.

The 2x6s look more permanent but not overly structural due to how they are installed at the posts. I've also never seen a pole barn with them.

Both are in my way for insulation and sheeting so they likely gotta go regardless. I'm planning on adding rafter ties.

Thoughts??

 

[joe--h]

I'd say get an engineer to look at it to figure out what they're doing.
And rafter ties where?
Joe H

 

[cvairwerks]

Appears to be 16' walls. so probably have to keep them for wind bracing.

 

[readhead]

The 45 degree braces in the wall are to support the truss that is landing midspan. The 2x4’s in the trusses are structural bracing. Based on my experience with metal buildings that use a similar brace the brace going from the column to the truss is to overcome the bending moment at the truss to column connections. Probably the result of using a two ply column. All the braces need to stay in my opinion. I’m not sure where or how you would install a collar tie on a truss.

 

[billp603]

Agree with getting an engineer to look at things, triangles that make gussets add a lot of strength to framing and Waterloo, NY = snow load. There should be plenty of insulation options that will work around them.

 

[jbwilkins]

I'm guessing the 2x6's are for uplift protection.....So the entire roof doesn't get torn off by winds.........You might be able to replace them with hurricane ties at every truss, but that may be a real pain to install....

To be clear, you have trusses, not rafters......and collar/rafters ties won't do anything for you. The trusses are already engineered to resist separation at the peak....

 

[travisn1]

Sorry, this is what I meant: https://www.homedepot.com/p/Simpson...e-ZMAX-Galvanized-Hurricane-Tie-H1Z/100374935

I'm ok with leaving the 2x6's I suppose, load transfer and all that, but the 2x4s look out of place, I'd expect the truss should be designed to take the snow load without scabbing in a 2x4.

With some further searching they are called knee braces, and their usefulness is for debate.

among others... https://www.garagejournal.com/forum/showthread.php?t=170626

I'll reach out to some architect friends and see if they know of any engineers I could entice to come over.

 

[matt_i]

You could easily install the H1Z uplift connector on the inside for each truss and it would function just fine in my opinion.

https://www.homedepot.com/p/Simpson...e-ZMAX-Galvanized-Hurricane-Tie-H1Z/100374935

Also in my opinion about what to do to improve bracing would be to better-brace the endwalls of the building. I don't see any wood-based bracing there. Custom cutting very long lengths of this flat strap and placing it in a large "X" pattern on the endwall is going to help racking resistance of the building immensely. You have to "tension" it by driving a nail in partially then using it as a lever. On the other endwall with the garage doors (I can see the track) "V" bracing is also an option. The good news is the flat strap won't interfere with wall coverings very much. True best practice would be to mark the path first and then rout or chisel 1/16" deep slots for the strap to sit in, then there will be no interference whatsoever.

https://www.homedepot.com/p/Simpson...-Gauge-Galvanized-Coiled-Strap-CS16/100375118

 

[rsanter]

The braces that come down to the walls appear to be to add shear strength to the building. I would not remove them.

The bracing that is up on the trusses (parallel to the ground) looks to be for squaring the building during construction but may add torsional strength as well

 

[travisn1]

Also in my opinion about what to do to improve bracing would be to better-brace the endwalls of the building. I don't see any wood-based bracing there. Custom cutting very long lengths of this flat strap and placing it in a large "X" pattern on the endwall is going to help racking resistance of the building immensely. You have to "tension" it by driving a nail in partially then using it as a lever. On the other endwall with the garage doors (I can see the track) "V" bracing is also an option. The good news is the flat strap won't interfere with wall coverings very much. True best practice would be to mark the path first and then rout or chisel 1/16" deep slots for the strap to sit in, then there will be no interference whatsoever.

You don't think having steel sheeting on both sides accomplishes the same?

 

[readhead]

Generally, and there are exceptions, these types of buildings, wood or steel, are self supported and do not rely on the steel sheeting for shear value. Most siding manufacturers do not list their product as providing shear value. Keep in mind that a siding panel is not flat or rigid like plywood or OSB.

Maybe Pudget Dude can way in on the expectations of metal siding in shear applications.

 

[travisn1]

Hmm. Good point. Further research is required

 

[Cougar]

Is it a name brand building.
If so contact them.

 

[WNYflyer]

Are the post/columns buried in the ground or do the post/columns sit up on concrete pier/walls, etc. ? If the post sit up on concrete then all the braces/supports are required. Even if the post/columns are buried in the ground those support/braces will greatly increase the rigidity of your building and cut down on the deflection of the building. Can't tell from the photo's but the eave height of your building looks quite large and that maybe one reason for the support/braces. The building looks very well constructed what with the knee braces being connected to a panel point on the roof trusses and looks like you have truss bottom chord bridging to brace the truss bottom chord from buckling when it goes in compression under wind roof uplift/suction loads. Of course those supports/braces are only as good as their end connections.

 

[Mattlt]

When was the last time you saw a building that was truly overbuilt? That said, do you really think you can remove anything from this building?

If this building was built by a reputable builder (vs someone who did not have engineered plans) you can be assured that all of this material is necessary.

I know if it were my building I wouldn't be cutting anything out of it!

 

[travisn1]

I think the garage is very well built; 5"- 5k psi concrete, buried posts, concrete all the way out to the lowest purlin. I haven't seen any branding anywhere on the building or any paperwork in the pile that was given to me with the house.

The walls are 16' and the peak looks to be at about 22'

Maybe I'll just move the knee braces up a couple feet on the posts so the angled wall section will clear the garage door tracks. This document from Kentucky shows knee bracing at 4' down, these are at 8'. snippet attached along with pic of no knee bracing for garage door tracks. LINK

Still trying to get a structural engineer out here to offer suggestions

 

[scottydosnntkno]

You can’t just use the specs of one builder to compare to another building. Every engineer and manufacturer does it differently.

The knee braces are absolutely required, as well as the angled 2x6s and the flat 2x in the attic. They all perform a different but critical function

With 16’ walls, there is massive wind loads trying to push the building over and twist the truss off the wall. The knee braces resist that force both ways, with one side pushing and one side pulling. Sure they provide uplift resistance, but you CANNOT replace it with a hurricane tie or similar Simpson strap. Very very different functions

The angled 2x6s are supporting the midspan truss. Some manufacturers would use a double 2x10 along the top to not need those. Again, why you can’t compare one designer/manufacturer to another.

The flat horizontal 2x are also shear blocks. They’re keeping that same wind that’s trying to push the building over from twisting the building down. They support the corners. Imagine you build a square of popsicle sticks, it’ll be super easy to break it by pushing on one corner or side off center. You add one, two or four angle pieces and it’s now much much stronger. The 2x4 are doing the same thing for your building.

And no, exterior metal siding is not rated for shear siding anywhere in the country that I know of. Pole barns are self supporting structures, and you could have metal siding, vinyl, or no siding (lean to/carport/canopy) and it would all work the same.

 

[travisn1]

I was able to talk it over with a local architect/friend and he was ok with moving the bracing up to clear the garage door track.

I think what I'm actually going to do is frame it in as is. There isn't a knee brace where the tracks are and it would be a lot of work just for an "even" appearance. I have enough projects going on that I'd rather spend time on.

What a roller coaster of emotions.

 

[mike93lx]

Are the post/columns buried in the ground or do the post/columns sit up on concrete pier/walls, etc. ? If the post sit up on concrete then all the braces/supports are required. Even if the post/columns are buried in the ground those support/braces will greatly increase the rigidity of your building and cut down on the deflection of the building. Can't tell from the photo's but the eave height of your building looks quite large and that maybe one reason for the support/braces. The building looks very well constructed what with the knee braces being connected to a panel point on the roof trusses and looks like you have truss bottom chord bridging to brace the truss bottom chord from buckling when it goes in compression under wind roof uplift/suction loads. Of course those supports/braces are only as good as their end connections.

The posts being buried or not cannot determine what bracing is needed, at all.

 

[WNYflyer]

The posts being buried or not cannot determine what bracing is needed, at all.

There are huge differences in the design of pole buildings that have posts sitting up on concrete versus those having the poles buried in the ground. This difference certainly has an effect on the required (if any) knee braces, side wall bracing, bottom chord bracing, etc. for the two different types of post supports. Posts buried or up on concrete piers are two different animals design wise.

 

[mike93lx]

There are huge differences in the design of pole buildings that have posts sitting up on concrete versus those having the poles buried in the ground. This difference certainly has an effect on the required (if any) knee braces, side wall bracing, bottom chord bracing, etc. for the two different types of post supports. Posts buried or up on concrete piers are two different animals design wise.

Nevermind. Not arguing this

 

[brownbagg]

you cant remove any of them, a post barn is pretty weak to begin with, you need all those 2x for wind loads, and keep it from racking

 

[Hooksdj]

Guys, I have a 40x60 stick building with 18’ eaves, T11 siding and a metal room. Each truss is constructed of what looks like 2 standard trusses connected by 2x6s making them double basically. I have built a 20x40 mezzanine on one end. Currently framing it out for a apartment with a loft area that has a lateral brace running through it. The floor of the loft/ceiling of the loft will be built with 2x6s that are connected to one side of a truss and the other to the wall separating the shop and mezzanine. The 2x6 lateral bracing runs from one end of my shop to the other end connecting to the other 3 trusses. My question is, since I am attaching the 2x6 floor joist/ceiling to the truss would it be possible to remove one section of the lateral brace that is within the mezzanine loft?

 

[travisn1]

I wouldn't touch a thing without getting a structural guy involved. Are you sure those trusses are rated to carry floor loading? your trusses look to be 12' apart, so each one is doing 3x more work than the standard 4' spaced truss. Did you get a permit for that living space addition? I would think if you were already paying someone that a 'simple' question like that would come free with the design.

Interesting note, you don't have any knee wall bracing, even with tall ceilings. I should have became an architect/structural engineer.

 

[Hooksdj]

The mezzanine is supported from bottom, NOT the truss. The truss in question runs through the loft area above the mezzanine. The only 2 lateral braces or bottom chords I am thinking of removing are on side of this one truss. The ceiling of the mezzanine and floor of the loft (joist) are attached to the truss but supported from walls below. Since the joist are supported from below and attaching to the truss I that they would be sufficient lateral bracing. Hope that helps make better sense of things.


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