Code for built up girder is no more than 4 lams , nailed
with 20d at 32 inches W pattern, two over each other at
ends and splices.
Question is can I use bolts and washers instead of nails
or use lag type specialty bolts such as TimberLoks?
What size bolts if used?
Replies
Depends on whether or not you have to meet code. If it will be inspected, then you need to find out what code book they use and go by that, or ask the inspector. Regardless of how strong it is, if it doesn't meet the inspectors criteria, you'll do it again.
I'm sorry, I thought you wanted it done the right way.
I sort of figured that was going to be the case. No, it
isnt going to be inspected. I understand the routine
and why there is a routine, but.....
I've seen lams go in that are bolted, and this
on inspected jobs, I was curious if I could
do a little better than code.
Just what is your objection to nailing, anyway?
Firstly, remember tnat when u drill holes you weaken the beam. The # of bolts to achieve the desired distribution could impact the effectiveness. Then, if you are going to wrap the beam you'll have to make provision for the heads - either deep holes in the d/w or, worse, the beam.
2ndly, yes, I've actually used bolts, 2 - 5/8" bolts @ 4' o/c. DON'T TAKE MY WORD ON THIS. It was a one-off - with the BI's recommendations and appro
cheers
***I'm a contractor - but I'm trying to go straight!***
I've never heard of a code that limits how many plies a beam can be. What code are you referring to?
The only reason I've seen bolts used to if the beam is loaded from one side only. The bolts are used to transfer load to the other plies.
I've never seen lag bolts used, and I don't think they'd fly. But that's just speculation.
Boss, code here says[and this is from memory]any member having more than 4 plys is to be lagged or bolted.Depends on the load,too, how many bolts to be used.
Say for some reason, you need 4 top plates, they will be lagged,etc.
First, I'm tossing out the question and appreciate all
remarks. I have no objection to nailing, simply looking
for something better IF IT EXISTS.
Interestingly the girder is loaded on one side only,
this is the way they built the house. I am only
following what exists. This is a repair.
As a side note, a guy gave me some 2x4's he
laminated into 4x4s for pump jacks. They
were gun nailed together with nails that are
ringed on the lower half. Mother of God! They
have the holding power that is astonishing.
Try pulling them out even with a 2 foot bar.
By the way, the load on the girder is one sided but
it is in the vertical plane. If you hang a deck off
your house and you attach to the rim joist , they
wnat bolts not lags. I imagine this is because
the load could become lateral.
Following up my original post is this answer from the folksat FastenMaster who make the Trusslok and Timberloklag screws.Note he asked about a code cite for the nailing scheduleon built-up lumber. I saw this posted on the web:NAILING SCHEDULE - 1994 UBC TABLE 23-I-Q International Conference of Building Officials" 24. Built-up girder and beams 20d @ 32" (813 mm)o.c. at top and bottom and staggered, 2-20d at ends and at each splice. "I do not have the entire publication in front of me, this isan excerpt, so I do not know about allowed number of plywith nails, use of bolts and washers or lags.Here is the reps reply:The TimberLok, applied to an application in shear, where the last ply has full thread engagement, can be replaced one to one versus a 20d nail. However, two issues. First, the TimberLok does not come in a 4.5" length (yet) so getting full thread engagement in the last piece cannot be accomplished. Second, the nailing pattern you've described, one 20d nail every 32" (from one side?) is the lowest I've heard. For 3-ply LVL beams for instance, they require two 1/2" bolts every 24" as a minimum. Good news is that we will have a new product on the market shortly that will measure 4.5" and have a greater capacity than the TimberLok. Unfortunately, it will be 2-3 months before you see it on the shelves.One question for you, could you point me to any code (IRC or IBC) that shows the fastening pattern you described. I'm always looking to add to my files new applications and patterns.