Finger joint bit, or ??

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Forum topic by crank49 posted 09-06-2013 01:24 PM 1287 views 0 times favorited 10 replies Add to Favorites Watch
View crank49's profile


4032 posts in 2992 days

09-06-2013 01:24 PM

Topic tags/keywords: glue lam fabricated beam joinery butt end joint question

I’m planning to build a “glue lam” beam of stacked 2×4s.
Can’ get 2×4s as long as the beam needs to be so there will be end to end joints required.
Any suggestions on the best way to splice 2×4s for a 26ft beam.
My first thought was finger joint, but I don’t have the bit for that.
My second thought was pinned lap joint.
Any more suggestions???

10 replies so far

View bondogaposis's profile


4753 posts in 2373 days

#1 posted 09-06-2013 01:32 PM

Scarf joint.

-- Bondo Gaposis

View sandhill's profile


2128 posts in 3945 days

#2 posted 09-06-2013 02:50 PM

Assuming it has to be 2X4 and no bigger I second the Scarf joint If you can do 4X4 just over lap them same thing as a scarf essentially the same thing.

View Bluepine38's profile


3379 posts in 3107 days

#3 posted 09-06-2013 03:05 PM

As bondo said scarf joint, but if you go that way, I have found a compound miter saw was the easiest way
to cut the scarf, and remember to clamp on both sides of the scarf joint before you apply pressure to the
scarf or when you put pressure on the joint it will tend to slide on you, or you could pin it with wooden pegs.

-- As ever, Gus-the 79 yr young apprentice carpenter

View crank49's profile


4032 posts in 2992 days

#4 posted 09-06-2013 03:06 PM

I’m building a beam 3 1/2” wide and 13 1/2” tall by 26 ft long to replace a rotted out timber in an old building downtown.
The original beam was one piece of clear poplar, 2 1/2” x 13” by 26 ft long.
It was installed over 100 years ago.

View Shawn Masterson's profile

Shawn Masterson

1325 posts in 1970 days

#5 posted 09-06-2013 03:32 PM

A manufactured glue lam is normally chambered for settle factor once it is loaded across the span. It is a little more than a stack of 2×4’s glued together. I really don’t see where you are profiting from making it vs buying it. If memory serves me right they aren’t that costly. An LVL would be even stronger and could be assembled in place so less man power to install it. Also by building it you take on the liability it is were to fail and the building were to come down. just my thoughts

View crank49's profile


4032 posts in 2992 days

#6 posted 09-06-2013 03:43 PM

Have to build it in place, and I do plan to build it with a camber.
I would replace the old timber with a steel beam if it was my choice, but the customer is always right you know.
Plus, if he wants to pay for the engineering to build it his way I don’t really care what it costs as long as I get paid for my work and the engineer signs off on it.

View MT_Stringer's profile


3172 posts in 3252 days

#7 posted 09-06-2013 03:52 PM

Good luck. Post some pics of the project before, during and after if you find time.

-- Handcrafted by Mike Henderson - Channelview, Texas

View higtron's profile


237 posts in 2699 days

#8 posted 09-06-2013 04:14 PM

Sorry just read the answer to my question oops I deleted my original post

-- A friend will help you move, a good friend will help you move a body

View sandhill's profile


2128 posts in 3945 days

#9 posted 09-11-2013 03:33 AM

I would check the span tables for beams it should tell you how the joint should be supported and how far apart joints can be without support. If its a public building your ars is on the line if there is a failure engineer or not even if an engineer did the specs. your the Lic. contractor.

View RPhillips's profile


1182 posts in 1858 days

#10 posted 09-25-2013 01:31 AM

I can’t believe that an engineer is recommending this…or that it’s even within code.

a LVL would be much more practical, stronger, and probably cheaper. If I remember right, even codes for residential are beginning to require LVL’s (like over doors and windows, etc). Steel beam would be my choice…

-- Rob - Indianapolis IN - Learning... one mistake at a time...

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