End joined Lumber

[KB2016]

Hi folks,

It gave me uncomfortable feeling when we observed end-joined studs is used for entire framing for a 2 story residential building. I have seen using 20-30% of the studs but not 100%.
Moreover most of the cases the studs has 3 to 5 joints for only 12 ft height! I understand per IRC, end-joined lumber is acceptable to use in load bearing walls. But I am having heard time to approve the framing.

Please suggest what to look from the supplier to be me in comfortable side. Thank you in advance.

Regards !

 

[dik]

End grain can embed in endgrain so, you might consider a splice in each second stud and only one per height... and you might consider a 'scab' nailed to each side of the splice. looks like they are trying to use a stud built up from a bunch of little 'sticks'... any lateral loads on the wall due to wind, etc.?

Dik

 

[XR250]

My understanding from the suppliers is that finger-jointed studs and rafters are as strong as their whole counterparts. I have never seen any data back this up, however. I also have never seen more than one joint in a 12 ft. stick.
There must be enough economy in using drops to make it worthwhile.

 

[KB2016]

XR250,

I have the same observation over the past. I never see more than one joint,and joined/spliced studs used not for entire building. may be 10-20% studs for entire building !

 

[dhengr]

KB2016:
Are they finger jointed or just butt jointed? Plain butt jointing, particularly in the field, is suspect as to tight bearing fit-up, continuity through the joint and then on both sides of the joined member, etc. Finger joints should be just fine in terms of strength and continuity. When done properly, finger joints are as strong as the base wood material is. They do allow much more efficient use of the lumber, in that big knots, splits, shakes, sloped grain, etc. can be cut out of the stick which would otherwise make it unusable. When fully mechanized, this is apparently a pretty efficient process, almost like extruding a long stick and cutting it to length. The biggest issue is the glue (glue joint) quality in terms of longevity and moisture resistance, etc. Early in their development the finger joints just came apart after some years, mostly due to moisture issues with the glue, as if there was no glue in the joint. With improved water/moisture resistant (water proof?) glues, the quality/longevity of the joints has improved too. I would ask the lumber supplier/manufacturer for testing reports and literature, ICC-ES reports, etc. on their material. What do they offer in the way of a quality, strength and longevity warranty? There will be different levels of warranty, and probably none for constant moisture contact (unprotected from the weather).

This has kinda been the history of glue usage in the construction industry. Early glues failed pretty quickly due to any moisture, quality workmanship and attention to detail were also issues. This scared the hell out of everyone, and set the use of glue for anything of structural significance back years. Just think of the early GlueLams, early plywood, early chip board, etc. etc., they all went through a few cycles of less than stiller performance before they got the glue right.

 

[oldestguy]

I'd pose the original question to the US Forest Products lab in Madison, WI. Chances re they have run typical wall sections through some stress tests. I'd suspect the external sheathing and interior drywall makes a significance effect on wall strength.