Pole building - is this piece structural?

[525playa]

Hi everyone, long time lurker.. pretty sure this is also my first time posting! I have a question on some 2x4s that span the center length of my 24x36 ft pole building. I wanted to know if these pieces are structural or not. They're only 2x4s, so I can't imagine they are doing much. I haven't seen any other pole buildings with a 2x4 running down the centerline at the bottom of the trusses.

Any insight?

Thank you!

Marc

 

[PelicanPines]

Looks like they are to prevent the trusses from bowing. I am assuming they are attached the vertical end beam there and nailed off on each truss. I would NOT recommend removal.

I am not a structural engineer ... but did live in a Holiday Inn for almost 2 years.

 

[kj_mustang]

I have three rows of them on my building but they are laid flat on the 3.5" side. Spaced out evenly across my 32' wide building.

 

[Snip]

I would have to agree with Pines. In my opinion I would consider them semi structural as they keep the bottom cord from shifting as pressure is applied on the roof system. My building is 66' long and the Amish that built it ran 2x4's flat down the center. I added some left over 2x6's along side for better walkway.

 

[larry_g]

If you look at my building below you will see that I have two 'rat runs' tying my trusses to the end walls. They provide strength because they are in tension.

lg
no neat sig line

 

[WNYflyer]

They ("bridging") are often required to brace the bottom chords of the roof trusses should the bottom chords go into compression due to wind uplift/suction on the roof. In commercial construction utilizing steel trusses/joists similar are required by OSHA for erection safety purposes as well as often for wind uplift on the roof, see Walmart, HD roofs, etc. In your case only the original designer/erection plans would indicate if they are still required once the building is buttoned up.

 

[RPH]

Yup, structural. Do not remove,

 

[justler]

Ties bottom cord to outside post to transfer load from wind and they use it to keep the truss spacing consistent in the center as well I think. Would be nice to see the top tied in as well... When you get up there you can probably feel the trusses move back and forth if you push/shake them from the top. Mine you can a bit, but it's to engineered spec.

 

[billconner]

I think you need to find original plans. These look like a pair of trusses every 12'. Guessing there was an engineered drawing for that.

If 12' post spacing and wince Hansen Buildings does the 12' spacing, you might take a shot at asking there. They have a small q&a section on their site - Mike's blog? - and get an answer from an engineer.

A lot of the buildings I've worked on are bar joists and they have lower chord bracing - angles - and every structural engineer I've asked om those projects says it can be removed after installation. (Getting a contractor to do it has never been easy!) Steel bar joists and these wood trusses are not the same but both are trusses and I'm pretty see u're the bottom chord is going to be in tension once loaded.

Obviously a structural engineer looking at it is quickest and best way, but probably most expensive.

 

[solows10]

Depend on your local building code. Mine in SW Mi says that i need "rat runs" to run the length of the building at the vertical supports of my trusses.

 

[dfiler2]

Those braces are very structural, besides giving the rats a place to run they keep the bottom chord of the rafter in line with the top. Ive seen lots of newer pole barns collapse from snow, almost all of them were caused by the lack of or removal of those braces. Most truss manufactures put a mark where those braces need to be. Depending on the width of the building there may be some needed up in the webbing also.

 

[Firebrick43]

Those braces are very structural, besides giving the rats a place to run they keep the bottom chord of the rafter in line with the top. Ive seen lots of newer pole barns collapse from snow, almost all of them were caused by the lack of or removal of those braces. Most truss manufactures put a mark where those braces need to be. Depending on the width of the building there may be some needed up in the webbing also.

+1.

Every truss plan I have seen lays out where and what bracing needs to be installed. Do not remove.

 

[mikedodge]

Mine is around 40 feet wide and has 3 of those strips that run the length of the building.

 

[525playa]

I am the worst when it comes to replying, but I truly appreciate the insight. Thank you all for the responses.

I recognize the need to stabilize the trusses with the structure, but I do have a couple follow-up questions:

1. Can I remove the rat run altogether if I box in the bottom of the truss with another 2x6?
2. If it must remain, can I remove the center rat run and install 2 off the sides? Pic attached.

The reason I am asking is that I would like to run a large ceiling fan in the center of the building.

 

[mike93lx]

I can't picture how boxing in the truss would help, but if this was my shop, I think I'd add a pair lengthwise and then just remove the section of the middle bay that's in the way of the fan.

Not an engineer

 

[Leaflessshadetree]

Why not raise (or lower) the fan so it is above (or below) the framing?

 

[larry_g]

Larry_G's shop build

Good People I have been in the playing with cars since before getting a drivers license. Some of my first work was done in the driveway at the folks place. We bought our first house with a 1 ½ car garage some 30+ years ago. I worked out of that garage for 10 years till I was able to afford a...

www.garagejournal.com

You can see in the link above where in my shop it was specified that the trusses be connected/boxed on the bottom and that the two rat runs be spaced some distance apart where they lined up with the two posts on the end wall.. So yes you can box the trusses together but you still need the rat runs to tie the trusses to the endwall. Be aware that my trusses are 36' long.

On second look you have already tied the the truss pairs together. I don't think an additional 2x6 will do anything additional.