Best way to splice a structural ridge beam?

[Ernest T. Bass]

Hey guys,

Framing an open loft, and I'm gonna need a doubled 14''-deep lvl ridge beam with bearing posts every 12'. In order to do the job safely with muscle-power, I'm thinking we should splice over the posts, instead of full-length 36' beams. What's the best way to do this? Could we simply offset the seams of the paired lvls by a foot or so over the post, or should all the seams be directly over the bearing? In which case, I'm thinking metal gussets or a 2x4 cap to tie the seams together.

Thanks!
Andrew

[rwanders]

If you have road access-----I have found that suppliers of large beams usually deliver them with a crane truck and, if you have the supporting framing in place, they have always been willing to set them for me without any extra charge. They will use their crane to unload them---setting them in place does not cause them any significant delay if you are prepared (and there). My last one was 6x16x36'

[MountainDon]

I'd ask the folks doing the engineering to produce the ridge beam before assuming that splicing would work. Things change when spices are made to beams and girders.

[SouthernTier]

I'm in the same boat with the design for my eventual cabin.  My design is a 25' long cabin, with spans of 11' and 14'.  No road access, so I'd be looking at 3 11-inch LVLs that could be lifted up by muscle power and scaffolding.

I'm an engineer and am doing the calculations myself (not a structural engineer - I'll have someone else stamp it - but I did my research on how to calculate this).  My understanding is that bearing calculation applies only to the span.  So as long as the beams rest on the posts, then splicing doesn't matter.  If you spliced in the middle of the span, then all bets are off.

If you want offset splices, then perhaps you could do 2 24' and 2 12' beams (12 + 24 paired with 24 + 12).  But maybe that is too much muscle power needed.

There may be minimum lengths of the beam that bear on the posts, however, which influences the size of the posts.

That all said, I'd be interested in hearing what Don_P has to say.

[Ernest T. Bass]

Yes, definitely putting the splices on posts like I said, so your basically treating the ridge load as multiple shorter spans..

Living where we do, I am doubtful that we will have a crane with our delivery. Last time we got 20' lvls they came on a flatbed, but I'll find out soon. Just wondering what my other options were.

[davidj]

Our 30' 800lb ridge beam came on a flatbed.  It was on rollers and we just pushed it off the back once the driver had reversed hard and hit the brakes to get it roughly in position.  We had to rent the crane separately.

[SouthernTier]

According to this:

http://www.diamondhillplywood.com/LVL%20Guide_07-0816c.pdf

a 14" LVL is 6.6 lbs/ft.  So for a 12-foot section, that is 79 lb.  Not too bad.  That's for a 1 3/4" width.

Lot's more data at http://www.gp.com/BUILD/DocumentViewer.aspx?repository=BP&elementid=9563 including bearing widths.

For my design, I would be using 9.25" (tripled).  So even going to a 24' length is only 211 lb.

[Don_P]

Our trusses and beams typically come on a roll off delivery. Boom trucks can usually get in but we have been out of easy options before.

Two of us lifted a pair of ~28' long x 24" deep LVL's a few months ago... and one of us was a girl  . Outsmarting large inanimate objects is the biggest part of construction (we took the sashes out of some honker windows in order to install them today).

If you have access to scaffolding a pair of towers with a beam between them works.

We dangled a chain from the beam above and used 2 come-alongs. We would hitch up one come along and lift till it was stroked out then hitch the next one higher and repeat, leapfrogging them until we had it above our posts then held it in place as we slowly lowered. Come-alongs are not made for vertical lifting so this is non OSHA bigtime. I get cortisone when the reminder of a lift gone wrong reminds me of how fast a come along can drop a load. Make certain the catch pawl is fully engaged with each and every stroke. The scaffold feet should be supported on heavy 2x's spreading the load over several joists, you don't want to punch a leg through the subfloor.

I've also built wooden towers out of framing to do basically the same thing, brace them off well.

I've set up pump jacks with braced poles and slung the beam underneath. With planks on the pump jacks you can walk from one to the next and lift impressive stuff solo just a few pumps at a time. The pump jacks are lowered below the ridge here after setting it. We have a jib in place with a block and tackle attached to lift the timber rafters into place.


Windlass, that's over a ton on the ground getting ready to be tipped up, notice the brake on the top handle, we could drop it into place and take a rest at any time;


These are all more dangerous than a crane, but, not more dangerous than two guys carrying a large beam up ladders.

If you try for a lapped splice the free ends are going to be scissoring in opposite directions, tearing the lap apart. If it has to be spliced I'd use a saddle and butt the two sections making two simple spans. MD is right, let the vendor supply the connection detail.

[Ernest T. Bass]

Some impressive but simple physics at work there! I'm not sure if I grasp why the scissoring action would happen, but it sounds like making the whole 36' might be easier than I thought, one way or the other...