Rafter to Ridge Beam Connection

Xtrememtnbiker · Jul 7, 2017

We are building a screen porch for a client that has been designed by the architect with a double LVL ridge beam for the purpose of having a vaulted ceiling. I asked him how to connect the rafters and he said he's not an engineer and to look online for a prescriptive method.

Having never had to connect rafters to a ridge beam before, always done it in a ridge board scenario with collar ties, I'm trying to find a prescriptive way of attaching the rafters to the beam with no results I feel great about. Roof pitch is about a 5/12 and the porch is about 15' wide.

I don't know if nailing them the same way we do for a ridge board works or do I notch the top with a birds mouth for it to sit on the beam, etc...?

Any advice would be great. Trying to get this framed tomorrow.

Tinstaafl · Jul 7, 2017

You almost don't have to fasten rafters to a ridge at all, other than to keep them from shifting position before you get the sheathing on, when there are joists or collar ties to keep them from pushing the walls out.

Since you have a structural ridge beam that won't be pushing downward on the rafters, basically they are just serving as a bridge between the wall plate and the ridge. Just nail 'em like you're used to, and you should be fine.

Insert usual legal disclaimer here. :whistling:

Jaws · Jul 7, 2017

Normally on a single ridge end nail the first rafter thought the ridge, toe nail opposing rafter, at least 3 on one side and 2 on the other with the proper degree. On that double lvl for nailing properly would pass inspection all day here. The ridge carries the burden.

Xtrememtnbiker · Jul 7, 2017

Tinstaafl said:
You almost don't have to fasten rafters to a ridge at all, other than to keep them from shifting position before you get the sheathing on, when there are joists or collar ties to keep them from pushing the walls out.

Since you have a structural ridge beam that won't be pushing downward on the rafters, basically they are just serving as a bridge between the wall plate and the ridge. Just nail 'em like you're used to, and you should be fine.

Insert usual legal disclaimer here. :whistling:

And you do realize there are no collar ties or rafter ties in this plan?

I'll be the first to admit I'm extremely under educated on more complex framing (not that this is it...), loads, stresses, etc so I'm trying to make sure I get this right the first time.

Calidecks · Jul 7, 2017

You can end nail both sides. Stick your gun into the crotch of the rafters at a slight angle.

Edit: I see you are connecting too an LVL. Toenail.

Mike.
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[emoji631][emoji631]

griz · Jul 7, 2017

I've seen a shaped plywood gusset and a bolt thru shaped steel plate to connect opposing rafters above a ridge.

Also seen a solid shaped plate to on top of the ridge to fill the space between the eafters and beam to provide nailing.

Pretty chitty answer from the architect to leave you hanging like that.

Submit a formal RFI describing the problem and state there is no detail for a connection and please advise how to proceed. Include the owners in the RFI....

They paid the SOB for plans he should provide them....

Xtrememtnbiker · Jul 7, 2017

Jaws said:
Normally on a single ridge end nail the first rafter thought the ridge, toe nail opposing rafter, at least 3 on one side and 2 on the other with the proper degree. On that double lvl for nailing properly would pass inspection all day here. The ridge carries the burden.

As you described is our normal nailing pattern. With the double, as you said, we will have to do the 3 and 2 on both sides of the ridge.

Maybe I'm over worrying about how all these members affect each other and I'm not educated enough to understand it all yet. I would have thought that more than nails would be needed for there to not be outward forces on the top of the lower beams the rafters are sitting on.

Triple 2x6 on top of 6x6 posts for the "walls" since it's a screen porch.

Calidecks · Jul 7, 2017

All the downward weight should be on the ridge beam and king posts. There should be zero outward pressure on the exterior walls.

Mike.
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[emoji631][emoji631]

griz · Jul 7, 2017

Jaws said:
Normally on a single ridge end nail the first rafter thought the ridge, toe nail opposing rafter, at least 3 on one side and 2 on the other with the proper degree. On that double lvl for nailing properly would pass inspection all day here. The ridge carries the burden.

Californiadecks said:
You can end nail both sides. Stick your gun into the crotch of the rafters at a slight angle.

Edit: I see you are connecting too an LVL. Toenail.

Mike.
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[emoji631][emoji631]

I agree it is a simple fix....

just trying to stir chit for a dumb azz architect....

Jaws · Jul 7, 2017

The rafters should properly sized for the load, taking into account
That no collar ties will be used. What would a Simpson tie or the like do in the event of a sagging ridge? The walls would kick out first.

I've used steel, steel/wood hybrid ect , scissor trusses, a lot of options depending on details.

Xtrememtnbiker · Jul 7, 2017

griz said:
I've seen a shaped plywood gusset and a bolt thru shaped steel plate to connect opposing rafters above a ridge.

Also seen a solid shaped plate to on top of the ridge to fill the space between the eafters and beam to provide nailing.

Pretty chitty answer from the architect to leave you hanging like that.

Submit a formal RFI describing the problem and state there is no detail for a connection and please advise how to proceed. Include the owners in the RFI....

They paid the SOB for plans he should provide them....

Yeah but you live in California so I can't take answers from you. :laughing:

All jokes aside, I'm assuming the code is worse for you guys out there because of seismic issues right?

Architect is a mutual friend of mine and the client. I was surprised at the answer I got but it sounded outside his scope to provide that info I guess. We don't have much experience working with architects and engineers.

griz · Jul 7, 2017

Xtrememtnbiker said:
Yeah but you live in California so I can't take answers from you. :laughing:

All jokes aside, I'm assuming the code is worse for you guys out there because of seismic issues right?

Architect is a mutual friend of mine and the client. I was surprised at the answer I got but it sounded outside his scope to provide that info I guess. We don't have much experience working with architects and engineers.

You could actually do nothing and be ok.

A little chewing gum would help.

Short Simpson strap to opposing rafters also works.

IT IS UP TO THE DESIGN PROFESSIONAL TO CALL OUT THE CONNECTION!!!!!!!!

Why did you need him in the first place??????

In California an architect can do his own engineering.....

They all go to the same kind of school where they mostly take classes in "I'm never wrong and everyone else is".....

Jaws · Jul 7, 2017

I'm actually certain most inspectors would want to see some kind of connectors in this case thinking about it. Part of the reason for collar ties is to keep the roof from seperating in the event of a very strong storm.

Every circumstance is different. As far as structure the nailing works fine. Has forever and ever

Jaws · Jul 7, 2017

PM Warren, 402, SBE or someone like that and I'm sure they'll throw you some advice as I'm sure they've run into it with inspectors.

If not PM me and email me the plan

Xtrememtnbiker · Jul 7, 2017

griz said:
You could actually do nothing and be ok.

A little chewing gum would help.

Short Simpson strap to opposing rafters also works.

IT IS UP TO THE DESIGN PROFESSIONAL TO CALL OUT THE CONNECTION!!!!!!!!

Why did you need him in the first place??????

In California an architect can do his own engineering.....

They all go to the same kind of school where they mostly take classes in "I'm never wrong and everyone else is".....

That's why I called him, cause he's the pro... :laughing:

Why we need him... I don't know. So we didn't have to draw the plans...? Like I said mutual friend. By the time we got called, the client already had the drawings from the architect.

Calidecks · Jul 7, 2017

We almost always have to put a strap across the top through the sheating over both rafters. Sometimes only every 4'.

Mike.
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[emoji631][emoji631]

Dirtywhiteboy · Jul 7, 2017

Out here they usually call for the hangers for rafters.

Calidecks · Jul 7, 2017

Dirtywhiteboy said:
Out here they usually call for the hangers for rafters.

I think his are exposed. Those are great for holding but don't look very clean.

Mike.
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[emoji631][emoji631]

Rio · Jul 7, 2017

Maybe some nice clean blocks and pressure block between the rafters on each side and also like Cali said strap across the top with ST18's or something like that, love pressure blocking.

Dirtywhiteboy · Jul 7, 2017

Californiadecks said:
I think his are exposed. Those are great for holding but don't look very clean.

Mike.
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[emoji631][emoji631]

He used the term vaulted. That makes me think drywall on them. A LVL nailed together is not very finished for exposed:blink: I like to call a exposed ceiling a Open Beam in that case I'd do it this way with the strips you showed on top.

Rafter to Ridge Beam Connection

Xtrememtnbiker

Tinstaafl

Jaws

Xtrememtnbiker

Calidecks

griz

Xtrememtnbiker

Calidecks

griz

Jaws

Xtrememtnbiker

griz

Jaws

Jaws

Xtrememtnbiker

Calidecks

Dirtywhiteboy

Calidecks

Rio

Dirtywhiteboy

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