Stick Built Building with Post Frame Trusses

[liljohn1972]

Hey everyone, I'm brand new to the forum, but i have lurked for as long as I can remember. Now I need help with something and I am hoping you guys can help. I am building a 34x48 garage and it is stick built with 2x6's on 2' centers. I was wondering about using post frame trusses on it every 4'. The slab is a mono slab with a 16" wide and 14" deep footing around it. The reason I am considering this is because I have an old chicken house that I was originally going to use the trusses off of. It was built with 2x4's and the trusses were every 4'. However, after doing all the work to take them down, I have decided against using them. My building is a similar construction to the old chicken house only it is beefed up with 2x6's and a better foundation. Does anyone see an issue with this or have ever doe this?

A side note, I live in the country with no code so this isn't an issue. I am however building it to code, but I don't HAVE to follow it.
Thanks everyone!

 

[mike93lx]

Code is minimum requirement... I don't think I would be looking to do less.

What are post frame trusses?

 

[liljohn1972]

Just a couple pictures of the process. I'll add more soon. I haven't taken any in a while.

 

[liljohn1972]

I know that code is minimum requirements and I am not looking to skirt around them, just looking to do something a little different.

 

[liljohn1972]

Code is minimum requirement... I don't think I would be looking to do less.

What are post frame trusses?

From what I understand, post frame trusses are more or less beefed up residential trusses made to span longer distances and are typically placed closer to 8' on centers as opposed to residential trusses that are every 2'.

 

[Firebrick43]

If you have 4' spacing then you have some type of beam built into the top of the stick framed wall to spread out the load or the wall sheathed.

A double top plate alone isn't going to hack it.

Another solution would be to notch the 2x6 at the top of the wall to nail in on edge a 2x10.

 

[liljohn1972]

If you have 4' spacing then you have some type of beam built into the top of the stick framed wall to spread out the load or the wall sheathed. A double top plate alone isn't going to hack it.

I am sheathing the wall with 7/16 zip board, the trusses will also all fall on studs.

 

[Firebrick43]

I am sheathing the wall with 7/16 zip board, the trusses will also all fall on studs.

Yes they fall on the studs, but only every other stud. In a regular platform framed building they fall on or close to every stud depending on 16 or 24" spacing.

Make sure you follow the nailing schedule which is every 6" on the panel edges and 12" on the studs. Many do not. I would even add a more to the top edge so your hitting both pieces of your double top plate.

Also be aware that its very likely that the chicken house trusses were never designed for ceiling loads that insulation plus drywall would place on them. And while you don't say where you are, if there is snow loads, most ag buildings are designed with less snow load than a residential building.

Are the metal fastenings of the chickhouse still good after years of the corrosive manure?

 

[liljohn1972]

Yes they fall on the studs, but only every other stud. In a regular platform framed building they fall on or close to every stud depending on 16 or 24" spacing.

Make sure you follow the nailing schedule which is every 6" on the panel edges and 12" on the studs. Many do not. I would even add a more to the top edge so your hitting both pieces of your double top plate.

Also be aware that its very likely that the chicken house trusses were never designed for ceiling loads that insulation plus drywall would place on them. And while you don't say where you are, if there is snow loads, most ag buildings are designed with less snow load than a residential building.

Are the metal fastenings of the chickhouse still good after years of the corrosive manure?

I am in southwest MO. As far a nailing, I am being very diligent in the nailing pattern, I am also adding noggins at the seems of the Zip, so it will be getting the full nailing pattern on all 4 sides.

The ceiling loads are actually why I decided not to go with the chicken house trusses. They are old handmade, oak trusses and the nails are actually all still in great condition. The reason I am curious about post frame trusses as opposed to residential is that I have it in my head that they are stronger when spanning the 34' that these will be spanning. I don't know if this is correct or not, but that is my reasoning.

 

[stingry]

First of all, good decision not to reuse the chicken house “trusses” which are not true trusses and are poorly designed. I can see from the picture that they are sagging. Just use properly engineered trusses on 2’ centers and be done with it.

 

[Firebrick43]

I am in southwest MO. As far a nailing, I am being very diligent in the nailing pattern, I am also adding noggins at the seems of the Zip, so it will be getting the full nailing pattern on all 4 sides.

The ceiling loads are actually why I decided not to go with the chicken house trusses. They are old handmade, oak trusses and the nails are actually all still in great condition. The reason I am curious about post frame trusses as opposed to residential is that I have it in my head that they are stronger when spanning the 34' that these will be spanning. I don't know if this is correct or not, but that is my reasoning.

Sorry I guess I misread and that you are talking about new trusses.

So 4’ spaced trusses could work, and if you order the right ones they could handle the loads. But they won’t be any stronger than the same load rated trusses on 2’

I don’t know what you are doing for roofing but if your sheathing for shingles you still have to put purlins down over 4’ spaced trusses where you don’t for 2’ spaced trusses so they will cost more due to that

And even if your using steel roofing with no sheathing you would need to strap the ceiling on the bottom cord.

 

[liljohn1972]

Ok, so it looks like the traditional 2' center regular trusses is the way to go. That is simple enough I'd rather spend the money now than pay for it later.

 

[billconner]

Between more expensive trusses and purlins (or 1 1/8" ply which will span 4') I don't think your material cost is going to vary much. If all contracted, less labor to set half the number of trusses.

From a code point of view, I think you need a registered design professional to at least review and seal the design. I suspect truss on a single 2x6 would be ok, just not prescriptive code.

 

[firebirdparts]

The post-frame trusses are fine if you prefer that style of construction. You can just double or triple studs under them if you spaced them out 8 or 10 or 12 feet (4 is nothing). Allowable end grain loading for framing lumber is enormous. The foundation, no matter how terrible it may be, will be gracious overkill compared to what post frame buildings have in the ground.