Pole barn roof question

[mfairbank]

Im building a 30x50x16 pole barn i have everything up just waiting on the trusses right now.

What would be a cheaper and easier way to do the purlins on the roof....

#1 I have the option of doing the purlins 2x6's on edge stacked on top of the trusses
-This way i would have to use more metal on the side of the barn but it would be easier doing the roof. but a little tricky getting them purlins nailed standing up and while laying the roof metal i would think it would be a little dangerous standing on them for the risk of one twisting and me falling

#2 or buying purlin hangars and have them cut to match the spacing of the trusses.
-This way i would have to buy a **** load of purlin hangars and nail them to the trusses every 2 feet and more expensive but the purlins would just slide into place


Any thoughs on what i should do??

 

[Rustyiron]

Sounds like your doing truss on post with 8' or so spacing, YES you need to hanger it. It adds to the stregnth of the whole roof system that is needed.
I kinda favor the old fashioned post/beam 2'o.c. truss, 2x4 laid flat (purlins)and easy ceiling/insulation finishing job. I really hate those short joist hanger nails!!

 

[RPW]

On mine the purlins are on edge welded to the trusses. That's how I've seen it done on many metal buildings.

Good luck.

 

[TRR]

There are air nailers out now that will handle those "short joist hanger" nails. I don't have one (yet) but all the reviews I've seen are favorable. Next construction job I have to do I plan to get one.

 

[mfairbank]

There are air nailers out now that will handle those "short joist hanger" nails. I don't have one (yet) but all the reviews I've seen are favorable. Next construction job I have to do I plan to get one.

what size nails do i use for the hangars....gotta be kinda small cause you don't want the nails running through to the other hanger on the other side of the truss. and seems like the smaller size nails you use the less strong they will be.

 

[randy41]

they make special nails that are like 16d but shorter.

 

[Duffster]

Im building a 30x50x16 pole barn i have everything up just waiting on the trusses right now.

What would be a cheaper and easier way to do the purlins on the roof....

#1 I have the option of doing the purlins 2x6's on edge stacked on top of the trusses
-This way i would have to use more metal on the side of the barn but it would be easier doing the roof. but a little tricky getting them purlins nailed standing up and while laying the roof metal i would think it would be a little dangerous standing on them for the risk of one twisting and me falling

#2 or buying purlin hangars and have them cut to match the spacing of the trusses.
-This way i would have to buy a **** load of purlin hangars and nail them to the trusses every 2 feet and more expensive but the purlins would just slide into place


Any thoughs on what i should do??

What is your truss spacing? 2x6s Seam awfully stout.

2x6s almost have to be set between the trusses but hangers are not necessary. You can use a 1x2 or 2x2 or bigger ledger board nailed to the side of the truss for the purlins to set on. This works very well. Saddle hangers can be a real PIA when it come to screw the roof steel down.

 

[mfairbank]

Sounds like your doing truss on post with 8' or so spacing, YES you need to hanger it. It adds to the stregnth of the whole roof system that is needed.
I kinda favor the old fashioned post/beam 2'o.c. truss, 2x4 laid flat (purlins)and easy ceiling/insulation finishing job. I really hate those short joist hanger nails!!

Yea i wish i could do my purlins 2x4's and laid flat but i have a couple of 12' spacing between the posts. So doing hangars is much stronger than just laying them up on edge on top of the trusses?
heres a couple of pics of what i got going on

 

[blueriver]

Can you put the rafters 4' O.C. and use 2x4's flat?

 

[mfairbank]

What is your truss spacing? 2x6s Seam awfully stout.

2x6s almost have to be set between the trusses but hangers are not necessary. You can use a 1x2 or 2x2 or bigger ledger board nailed to the side of the truss for the purlins to set on. This works very well. Saddle hangers can be a real PIA when it come to screw the roof steel down.

the post spacing is different all the way down the furthest is 12'.....Yea im sure the hangars are a real PIA but they shouldn't get in the way of the roof steel. The truss manufactors are calling for 2x6's for purlins for the best support. The top cord of the trusses are 2x6 so if i lay the ledger board down the 2x6 purlins would stick above the trusses a inch or 2...but that is a really good idea with the running a ledger board along side of the trusses it would save me some money on buying all them hangars but would it be as strong as the hangars??

 

[mfairbank]

Can you put the rafters 4' O.C. and use 2x4's flat?

That was my original plan but half of the trusses would just be free floating sitting on just a header and not being supported by the posts so i went this way to save money on not buying more trusses and more bolts to support them trusses but now i have to spend money on 2x6s instead of 2x4's and now i have to buy purlin hangars. so probably didn't save me any money in the long run.....but maybe it did since how trusses are about 100 dollars a piece

 

[Duffster]

Yea im sure the hangars are a real PIA but they shouldn't get in the way of the roof steel.

Saddle hangers do. Trust me. Been there and done that.

would it be as strong as the hangars??

Some argue stronger.

Why such a random spacing? Even with the random spacing you only need 2x6 where it is over 8-9'. You could hanger those and use 2x4 where it is only 8' and then hanger or ledger those.

Some would even go 2x4 up to 10' but I wouldn't reccomend that when setting the purlins in between the trusses.

 

[mfairbank]

Saddle hangers do. Trust me. Been there and done that.



Some argue stronger.

Why such a random spacing? Even with the random spacing you only need 2x6 where it is over 8-9'. You could hanger those and use 2x4 where it is only 8' and then hanger or ledger those.

well the random spacing comes with haveing 2- 12' door openings on the eve side so the first spacing is 5' then 12.6' then 3' then 12.6' then 8.6' then 8.6' oc. So i guess on the 5', 3', and the 2- 8.6' spacing i could use 2x4's on edge with that ledger board. Would that be enough strength for the roof?

 

[mfairbank]

Your talking about putting all the 2x4's and 2x6's on edge right??

 

[Duffster]

well the random spacing comes with haveing 2- 12' door openings on the eve side so the first spacing is 5' then 12.6' then 3' then 12.6' then 8.6' then 8.6' oc. So i guess on the 5', 3', and the 2- 8.6' spacing i could use 2x4's on edge with that ledger board. Would that be enough strength for the roof?

Absolutely.

Your talking about putting all the 2x4's and 2x6's on edge right??

Yes.

 

[mfairbank]

Absolutely.



Yes.

alright that sounds good and that should save me some money on the purlins....and hangars. Just courious how do you know all this...are you a contractor or just a expericed pole barn builder?? This is my first barn it has been pretty much fun this entire time. I was going to have someone do it myself but everyone i called wanted to charge me around 25 to 30,000 to build this barn. But all said and done should cost me around 16,000, pretty good savings doing it myself i would say!

 

[Duffster]

...are you a contractor or just a expericed pole barn builder??

Both.

 

[Rowdy Raven]

I just finished building mine and had kind of the same problem. Instead of putting 2x6s on edge I put on rough cut 4x4s. This gave me the strength to bridge between the trusses and a good wide edge to screw the metal into. I lapjointed the edges where they met along the course of the lateral run. Worked very well and I am able to walk on the roof easily.

 

[blueriver]

That was my original plan but half of the trusses would just be free floating sitting on just a header and not being supported by the posts so i went this way to save money on not buying more trusses and more bolts to support them trusses but now i have to spend money on 2x6s instead of 2x4's and now i have to buy purlin hangars. so probably didn't save me any money in the long run.....but maybe it did since how trusses are about 100 dollars a piece

Nail a stub pole or 2x6 to the top plate to fasten the rafter to ... if your worried about support put a plate on the inside just like the outside.

Don't know about the Cost difference... the darn hangers and long 2x6's are going to take up some time ...

 

[blueriver]

When I built mine I put a stub 2x4 ..