roof framing with 4x6's

[Sparticle]

Hey folks. We want to use up some 4x6's we have lying around for the roof of a new outbuilding. Haven't seen many roofs using this size lumber and wonder if its too heavy for this application. The vertical posts are 4x6 and 4x4, the ridge beam will be 4x6 too. What spacing can we use for these? Not much of a snow load here in southern Missouri. Thanks.

[The Paw]

you could definitely go with 24 inch spacing. The problem with going anymore than that, is then you might start to get deflection in the material spanning the 4 x 6 s, i.e. your osb/plywood or roof planks.

I think I would use the 4x6s in a mini post and beam structure, spacing the beams so that I could use 2x4s for the roof joists (which would then be 16" o.c.).

[ronbre]

make sure the side walls are strong enough to support a roof that heavy..but hey, it probably wouldn't blow away in a tornado !

[uncle Will in In.]

They would need to be tied together like trusses are to keep the side walls from spreading apart. If the roof isn't too wide, you could space them 4 feet apart, and use 2x4 stringers crossways on them at 2 foot spacing. Then you could put a steel roof on them. How wide will your building be???

[Sparticle]

The barn is 20 x 20. Gable roof. We're putting metal on it.

[solidwoods]

Take a minute to price trusses you may be amazed how cheap they are.
4x6 are heavy, not easy to attach to the ridge beam and they still need a collar tie to stop them from spreading. Trusses can be put up in a day , no special way to attach them, are rated for the span/load, and they are uniform.
jim

[haypoint]

Anyone with a bandsaw mill? It would be easy for them to re-saw your beams into 2x6s

What kind of wood?

I'll vote for buying trusses. Years ago, I cut some big trees, mostly red oak, and made lumber out of them. I needed boards for building horse stalls, so I used what I had. I have 2x12x 16' clear oak stall boards. They would have been better used in a house as stair treads or other woodwork. Using what you've got on hand isn't always the best.

[Sparticle]

We have a ton of these 4x6's already and want to put them to use and don't have the money to buy trusses. Is it okay to use a 4x6 for the ridge beam? Since we don't have one long enough for the entire length how do we go about connecting 2 together? Thanks for all the help.

[The Paw]

Originally Posted by Sparticle

We have a ton of these 4x6's already and want to put them to use and don't have the money to buy trusses. Is it okay to use a 4x6 for the ridge beam? Since we don't have one long enough for the entire length how do we go about connecting 2 together? Thanks for all the help.

If I was determined not to buy a long enough piece for the ridge beam, I guess I would use a lap joint and bolt them. But I would make sure I had a post underneath the spot where they joined....

[tiogacounty]

Originally Posted by The Paw

If I was determined not to buy a long enough piece for the ridge beam, I guess I would use a lap joint and bolt them. But I would make sure I had a post underneath the spot where they joined....

In a typical gable layout you have either ceiling joists or collar ties to "resolve the thrust" as engineers say. In plain english they prevent the roof from flattening out and turning into a floor, getting a nasty saddleback in the ridge, of simply collapsing. If the rafter pairs are adequately tied together with joists or ties, then there is no need for a ridge board, as it provides no required structural support. Don't believe it? there are hundreds of barns here in my area without ridge beams and they are doing pretty well over the last 100-200 years. Local tradition often involved rafter pairs that were half lapped at the peak and pegged. I would use a full length 2x8 ridge board, 4x6 rafters on 24" centers and 2x8 ceiling joists every 24". Hand nail everything together with 16d common nails and throw a hurricane strap on ever rafter tail where it sits on the wall. This would involve the purchase of 10- 2"x8"x20' boards, but it will result in a structure that will still be straight and strong long after we are gone. Given the choice between a pile of 4x6s I already owned and buying trusses, I would pass on the trusses. IMHO, they aren't cheap, difficult for DIYers, and rarely end up straight, level and square without a few experience framers on the job. That opinion is based on building dozens of truss roof with volunteers over the years. Good luck, and not only do I play builder on the keyboard, I do it in the real world also.

[Jolly]

Originally Posted by tiogacounty

In a typical gable layout you have either ceiling joists or collar ties to "resolve the thrust" as engineers say. In plain english they prevent the roof from flattening out and turning into a floor, getting a nasty saddleback in the ridge, of simply collapsing. If the rafter pairs are adequately tied together with joists or ties, then there is no need for a ridge board, as it provides no required structural support. Don't believe it? there are hundreds of barns here in my area without ridge beams and they are doing pretty well over the last 100-200 years. Local tradition often involved rafter pairs that were half lapped at the peak and pegged. I would use a full length 2x8 ridge board, 4x6 rafters on 24" centers and 2x8 ceiling joists every 24". Hand nail everything together with 16d common nails and throw a hurricane strap on ever rafter tail where it sits on the wall. This would involve the purchase of 10- 2"x8"x20' boards, but it will result in a structure that will still be straight and strong long after we are gone. Given the choice between a pile of 4x6s I already owned and buying trusses, I would pass on the trusses. IMHO, they aren't cheap, difficult for DIYers, and rarely end up straight, level and square without a few experience framers on the job. That opinion is based on building dozens of truss roof with volunteers over the years. Good luck, and not only do I play builder on the keyboard, I do it in the real world also.

He wrote it a lot better than I could...this is the way to go.

[The Paw]

Originally Posted by tiogacounty

In a typical gable layout you have either ceiling joists or collar ties to "resolve the thrust" as engineers say. In plain english they prevent the roof from flattening out and turning into a floor, getting a nasty saddleback in the ridge, of simply collapsing. If the rafter pairs are adequately tied together with joists or ties, then there is no need for a ridge board, as it provides no required structural support. Don't believe it? there are hundreds of barns here in my area without ridge beams and they are doing pretty well over the last 100-200 years. Local tradition often involved rafter pairs that were half lapped at the peak and pegged. I would use a full length 2x8 ridge board, 4x6 rafters on 24" centers and 2x8 ceiling joists every 24". Hand nail everything together with 16d common nails and throw a hurricane strap on ever rafter tail where it sits on the wall. This would involve the purchase of 10- 2"x8"x20' boards, but it will result in a structure that will still be straight and strong long after we are gone. Given the choice between a pile of 4x6s I already owned and buying trusses, I would pass on the trusses. IMHO, they aren't cheap, difficult for DIYers, and rarely end up straight, level and square without a few experience framers on the job. That opinion is based on building dozens of truss roof with volunteers over the years. Good luck, and not only do I play builder on the keyboard, I do it in the real world also.

Don't disagree with anything you said, when I have built sheds and such I tend to forgo ridge beams in favor of collar ties or trusses as well.

It's just that the dude seems determined not to buy an additional piece of lumber, and asked how to do it without buying the continuous ridge beam....