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Adding knee braces to new pole building

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zkdiesel

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Just put up this 176’ long building. Wind blows like hell out here and all my other pole buildings have knee braces, this one doesn’t.
Thinking about adding 45* 7’ long 2x8 knee braces on every other truss to the side pole. Completely unnecessary? Building is not getting any steel on inside as it’s “storage”
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All these other buildings have them as can be seen
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loganb

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We have similar bracing on most of our sheds in Kansas, not going to hurt a thing but a bit of clearance on the edge if you add it. For us the most common failure in wind events is the purlins get pulled off the rafters which of course takes the roof tin with it. Every time we reroofed a hog barn or shed a 4" or so screw went into every purlin to rafter joint.

The newer pole barns I've seen damaged in wind generally lost the roof at the rafter to post joint, older ones often had some weak posts the grade level and those snapped/bent and then caved in the wall
 
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jack stand

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It sure wouldn't be a negative zk!
That's a lot of wall!
Are your prevailing strong winds from any one particular direction/wall? It's a lot easier to just put some braces in regardless of the drawings, which in the case of failure means that 4 letter word.... lawyers and insurance companies.
I'd also add some diagonals down from the top of maybe every 3rd-4th post to the lowest wall girt above your perma-column.
 
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PopcornSutton

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If you can live with the overhead clearance issue along the wall, it won't hurt a thing. For peace of mind, it may be well worth it. Certainly no degradation to other members.
 
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mike93lx

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PopcornSutton said:
If you can live with the overhead clearance issue along the wall, it won't hurt a thing. For peace of mind, it may be well worth it. Certainly no degradation to other members.
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I'd want to know it's actual a benefit before doing all that work. That's a lot of money and time if it only "won't hurt" to have them.

The existing design could be rated higher than other failure points on the building.
 
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jblnut

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If it helps you sleep better I’d say go for it. Cheap piece of mind if you can live with the decreased head room which I’m sure you I can.

Farm stuff is typically not large square boxes that’ll hit on top, it’s wider at the bottom so betting close to the roof corners isn’t as large of a concern.

That being said. My shop and hay shed do not have knee braces. I spec’d them without them as I didn’t want them in the shop or in the way of hay. All other sheds have them on at least one wall.

Nice shed !! The permacolumns are a must in my opinion. We’re going to be putting up a 60x108 soon and it’ll go on piers with no knee braces.
 
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ATC

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I'd do it if it were me. Stronger is better. Might make a difference in a freak storm.
 
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NUTTSGT

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Think about it this way, how much strength are you going to gain with them ?

Because to add them, you're going to need to add blocking to the bottom cord of the trusses. Doing so is going to push the knee brace out from the trusses.
 
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theoldwizard1

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I assume you are referring to braces that (at least on typical garages) ran from top plate at the corner to the bottom plate at a 45° angle. Garages built in the 50s used 1x6 and had these "let in" to the studs on the outside before the sheathing was attached. I always heard the called "wind braces".

Beside the corners, I would add some additional cross ("X") braces in the middle of your much larger building. Simple metal bars about 1/8" thick.
 
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Stuart in MN

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WisJim said:
Engineered trusses can be funny things, and adding new knee braces could affect the rest of the truss in unexpected ways. I'd ask the engineer who designed the trusses and the building before adding or changing anything.
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This would be my concern. The trusses were engineered by someone, I'd ask your contractor to ask them first before doing anything.
 
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WNYflyer

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Looks like your trusses are designed to rotate at their ends when subjected to vertical loads, adding knee braces would restrain the rotation in some manner and throw loads into the trusses that they are were not designed for. Also the roof diaphragm and shear walls maybe so stiff that any knee braces added may do little to resist lateral winds loads. As long as the building was professionally designed and erected according to the plans I would not be worried but of course could contact the building designer and question them to get the warm fuzzies. By the way nice building.
 
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jack stand

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mike93lx said:
I'd want to know it's actual a benefit before doing all that work. That's a lot of money and time if it only "won't hurt" to have them.

The existing design could be rated higher than other failure points on the building.
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It's going to be a pita for the metal guys for sure!
 
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Boatman62

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20 something years ago I had 2 pole barns built a year apart. The first was going to be my shop and I didnt want any diagonals inside. It was designed like yours with the trusses being let into the posts and attached at both the top and bottom chords. That provided the racking resistance. The second was a boat storage facility and I didnt care about the diagonals. The trusses were set on top of the doubled rim joists and the diagonals provided racking resistance.
 
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PCustoms

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jack stand said:
👍 Beer for  her horses!
I don't think you've wasted your time. That 12"-14" connection to the post isn't much in consideration of the monstrous wind load against the walls.
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Doesn't that imply he did waste his time?
 
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Dagny

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My oldest pole shed has none. Early 60's. redwood poles doug fir 2x12s all bolted it's crooked and ugly but the roof don't leak.
 
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cmandp

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The funny thing is a picture of Notre Dame was posted. (Those are flying buttreses BTW)

Then zk posts a facsimile of the Effiel tower. That's some foreshadowing.
 
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zkdiesel

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cmandp said:
The funny thing is a picture of Notre Dame was posted. (Those are flying buttreses BTW)

Then zk posts a facsimile of the Effiel tower. That's some foreshadowing.
Click to expand...
My life’s a mess, if I had a therapist he’d quit or commit himself. My wife says I see the future….
 
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whateg01

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I constructed a 21 foot tall Eiffel tower from laser cut mdf and masonite for my son's 8th grade dance. Maybe not the smartest project I've ever suggested then took on, but it was cool. Even kids like the Eiffel tower!
 
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