Truss for pole building question..

[chucko]

attached is the type gable I was talking about

as far as the bacing book goes they mosty covery bracing for houses not pole barns but all the Temp. barcing is the same. They truss plant "should" suppy the book but I would tell them you want one if they charge for it I would not think it is much bucause they don't want you to sue if something happens

 

[chucko]

Lazy,

Let me see if I can explain the problem with putting the bracing between the trusses. Think of all those little 2’ (4’ or whatever) braces as having a hinge point at each end and think of the trusses a dominos.
Now lets say your on top of one of these dominos and it is a little out of plumb and a hinge is holding it from going over.
Now if that board goes over a bunch of the dominos with no hinges in that board the whole stack goes done. That is the reason for the x-bracing also.
I know what you’re thinking ……But I used a hanger so I am ok……nope you were lucky….A hanger is made to take the load vertical not to keep the board in it from rotating. Nail a hanger to a beam put you a short board in it hold the other end with only your hand and pull up or down and see how easy that hinge works.


I have never seen you barn but you might think about adding a few rat runs along the bottom side of the top chord of the trusses and x-bracing the gables.

Do you guys up there (I am in Fl so now snow) seen many pole barns that fall because of snow and think well the snow brought it down? Think again most likely it was lack of bracing. A building is a system and the trusses are just one part of that system….

Now with all that said I will add this. I have seen many buildings that are 100+ years old with no bracing and way too small of rafters…go firgue

 

[Glenn9643]

Chucko,

I've been a little confused with some of the terminology in this thread.
I've always understood "purlins" to be bracing placed within the wall structure horizonally between the studs, and tonailed to the studs. Sometimes referred to as fireblock, this was a standard in building construction before the advent of plywood sheathing. Purlins would also be placed between the rafters perhaps.
Horizonal pieces nailed or otherwise fastened to the side of the wall studs or rafters I have always understood to be called "lathing". These members are for the purpose of attaching plaster, metal sheathing, etc.
Maybe it's just a regional thing.

 

[chucko]

yea that is a big problem in const.....too many terms for the samething

purlins, rat runs, lathing are all the same (to me anyway)

the thing you need to understand about "fire blocks" and toe nails is they have no structural value

fire blocks are to slow a fire in the wall and or to catch the edge of the plywood only....or to make me say bad words when I have to pull a wire later /forums/images/graemlins/smile.gif

 

[chucko]

maybe this will help with Truss terms

http://www.alpeng.com/pdf/etrusses.pdf

Above has lots of good info in it (sample brace is shown too look at page 37 it shows what I was trying to say)

Below are some others also


http://www.truss-frame.com/design-common.html
http://www.artruss.com/trussparts.htm

 

[SteveBenson]

>or may say to wait until after the roof is installed and the truss is fully loaded before attaching it.

Up north that would mean waiting for a couple feet of snow before securing the trusses.

Also, the metal roof doesn't weigh much compared to the trusses themselves. Keep in mind that the gable end trusses are only supportting half the load of the interior trusses, so they aren't all going to be loaded evenly anyways.

 

[Evasive1]

As far as going straight to the manufacturer of the trusses and having them build them, in my experience it will still be cheaper to go through the lumbar yard, in your case Lowes, since they get discounts from the truss builder. Your trusses will also be more of a "priority" as far as a time frame for the truss builder if they are building them for Lowes. A few years ago I had a rush job on some roof trusses. The truss plant told me 5 weeks, (busy time of year), went through a major lumbar yard and had them in 3 weeks.
As far as the trusses on the end as almost everyone has said these will need to be structural trusses since they will only be supported on the ends, which will probably end up looking like all the other trusses on the building unless they put some extra "scabs" in it for attaching you metal on 2' horizontal centers.
Did not mean to confuse anybody about the truss for the 16' door. This has nothing to do with the roof trusses. It looks like a floor truss that is specifically designed to span the long distance of a 16' overhead door and be beefy enough to support the garage spring, brackets and automatic garage door opening equipment at far less weight than an lvl and a lot less expensive.
You are headed in the right direction and have it figured out. Now just the fun part of putting it all together and enjoying the finished job.
Duane

 

[Lazy]

Hi
here is the website of the folks that put up my building. They have built just about every building in this area and I have never heard of any falling down. I'm sure the building are well designed and meet all the building codes.

http://www.bblconst.com/buildings.htm

Charlie.

 

[mopower440]

Ok, so thats cleared up, but 2 questions, ok, if i add on some 'scabs' to the gable end trusses to attach the sheet metal lathing to, will it weaken the truss or anything? also, when i install the 16 foot garage door, is it ok to hold up the tracks and springs for the door by the truss like in a normal garage?

 

[jwstewar]

</font><font color="blue" class="small">( is it ok to hold up the tracks and springs for the door by the truss like in a normal garage? )</font>

Good question. I'll be following that answer closely as I'll be install 3, 9X8s in mine. What is everybody's opinion of a ceiling as well? I'm considering 7/16" OSB as a ceiling or maybe drywall depending on pricing and my mood at the time of purchase.