Need help with truss bracing

[BX25HD]

I have started to build a pole barn. It is 40 x 56 with 10 walls. I got the first truss up and nailed to the eve wall post. I'm using my tractor with a boom attached to my pallet forks. The boom is a 4x6x20 that was twisted and I did not want to use it on the building. After I set the second truss (four foot on center) I couldn't safely walk between the trusses to nail some purlins on to brace the truss. This is what I did on my dad's house last fall, but his trusses were two foot on center, 28 wide, and only 8 off of the deck. So my question is what is the best and safest way to put the purlins on after setting the truss? Oh, the trusses are 40 wide with no overhand and 4:12 pitch.

 

[Daronspicher]

I've been considering the same issue for building about the same building, might go with 12' ceiling.

I have access to a "dump truck" (think f450 with a small dump bed). I believe that bed height to be about 5 feet high and think I could bolt down about 6 feet of scaffolding in the bed. Once the rafter is lifted into place, I hope I can drive along side the building to set the sides of the truss on each side, then back under in the center with about an 11 foot standing height between trusses.

On a 4/12 there should be about a 6 to 7 foot height from bottom to top of truss, or about 8 foot from top of scaffold to top of truss. A short step stool on top of scaffold should enable me to plumb up the truss and attach it to the previous trusses (temporarily until purlins are installed.

Having a platform like that should lend nicely to most roofing activities I think.

I am just talking ideas, it would be great to hear from people who have actually done it.

 

[BeezFun]

Put planks on top of the bottom chords so you can walk from truss to truss. Better to use 16' so you don't have to move it so much, drag it along as you go. Probably just need one in the center, you can walk on the headers at the wall end.

 

[dfkrug]

Put planks on top of the bottom chords so you can walk from truss to truss.

That's what I did.

I also used the tractor with boom pole on the FEL to set the trusses,
but also used scaffolding to secure them in place, shifting the
scaffolding along the floor as I went.

 

[Darrenone]

I stood on the side wall and nailed one on as high as I could reach. Then stood on that one to nail the next. Don't disconnect whatever it is you use to put it up there until you have enough supports in place. Also, after you put up a few, run a diagonal brace. Make sure you put enough diagonal braces as I have seen the trusses fall over with not much of a wind.

 

[ldwain]

The industry documents for truss bracing are found at this website: Building Component Safety Information. The BCSI booklet describes the required bracing for truss systems. Specifically, the B10 document describes bracing for post frame buildings. And yes, diagonal bracing is ALWAYS required in truss systems.

 

[BX25HD]

The industry documents for truss bracing are found at this website: Building Component Safety Information. The BCSI booklet describes the required bracing for truss systems. Specifically, the B10 document describes bracing for post frame buildings. And yes, diagonal bracing is ALWAYS required in truss systems.

I received this document with the trusses. I was asking how to get up on my trusses safely to do what this document requires.

Thanks to everyone for the advice. I hope to get back to this project soon. I've been working a lot of overtime. Great for the bank account but bad for getting work done on the farm. Thanks again!

 

[RxRatedZ71]

We used 2 sections of scaffolding to set my perlins on my 12' wall barn. We had a hard time on the two most top ones. I think we had a step ladder on top of the scaffolding in the end (not OSHA approved). If you have a slab floor just put casters on your scaffolds and roll it around.

 

[BeezFun]

The industry documents for truss bracing are found at this website: Building Component Safety Information. The BCSI booklet describes the required bracing for truss systems. Specifically, the B10 document describes bracing for post frame buildings. And yes, diagonal bracing is ALWAYS required in truss systems.

Great link, thanks

 

[Luremaker]

The industry documents for truss bracing are found at this website: Building Component Safety Information. The BCSI booklet describes the required bracing for truss systems. Specifically, the B10 document describes bracing for post frame buildings. And yes, diagonal bracing is ALWAYS required in truss systems.

Thanks for the link. Don't all truss manufacturers provide you with the bracing requirements for their trusses? When I built my shop the building inspector wanted the engineering certificate from the truss manufacturer along the bracing sheet. The bracing sheet listed all required braces including lumber grade and size along with the number of nails, size of nails and where each nail had to be placed in the braces. It left no room for errors.

 

[ldwain]

Thanks for the link. Don't all truss manufacturers provide you with the bracing requirements for their trusses? When I built my shop the building inspector wanted the engineering certificate from the truss manufacturer along the bracing sheet. The bracing sheet listed all required braces including lumber grade and size along with the number of nails, size of nails and where each nail had to be placed in the braces. It left no room for errors.

No, typically bracing plans are outside the scope of the truss manufacture's design. The bracing shown on the truss design drawings is restraint of individual truss members (webs) that need to be braced to prevent buckling to due forces in the web members themselves. Bracing for loads not in the plane of the truss is typically not shown and is the building designer's responsibility since design of the rest of the building needs to be considered in order to properly transfer the loads to the foundation. Since many post frame structures do not involve a building designer, the BSCI documents can be used for guidance for the truss restraints. While some manufacturer's may provide this design as a service, most do not. As an example, ALL truss systems need diagonal bracing installed, this is not typically shown in the truss package, except in the BCSI documents delivered with the trusses. The exception to this would be if you purchased an engineered building package. In that case, the manufacturer of the building may have provided a building bracing plan that includes truss bracing. The bracing specified on the individual truss design drawing would still need to be installed to prevent in-plane buckling of the truss members.

 

[ThomasH]

To add just a bit to the previous discussion, truss bracing is typically specified depending on the expected wind load in the area for the building, so it varies in different parts of the country. Typical truss bracing is scissor bracing, although other may be required depending on the wind load and length of the truss. Scissor bracing is typically applied to the horizontal middle truss member, in a scissor fashion to take the thrust load of the hip of the roof and diagonally brace that to the bottom truss or wall header.

 

[crbr]

Thanks for the pictures.

 

[BX25HD]

Well I got all of the trusses up yesterday and pot all of the purlins on. I rented a 16' ladder to put on the purlins and the bracing. I'm glad that job is done!