What is the best way to join two 6X6 post together vertically? I’m building a deck whose decksurface is about 16 feet above the ground that will have a roof over part of it. There will be two posts that will run from the ground to support the deck and the roof beams. The largest 6X6 post I can buy is 20 feet long, but I’m going to need about 24 feet of of length. I’m thinking about using a 16 foot and and 8 foot long post, but am unsure about the best way to connect them together.
Thanks
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Replies
a long half lap scarf joint, glued with PL premium and thru bolted. I have used PT 8x8 at 24'...special order, but we got em. A real bitch to stand up tho'.
Spheramid Enterprises Architectural Woodworks
Repairs, Remodeling, Restorations.
Edited 8/9/2004 3:18 pm ET by SPHERE
Thanks for the quick response! How long is long for the half lap scarf joint? 12", 18"?
Thanks again!!
using yer example...4 FEET minimum.
Spheramid Enterprises Architectural Woodworks
Repairs, Remodeling, Restorations.
Thanks!
does not mean I condone the splice practice
The boat builder in me wants to say that a hook scarf, or, even better a locking hook scarf joint would be better for making a "mast," since that is the direction he's going. Might even look cool with contrasting wedges driven in . . .
I'm remembering that a structural scarf is 18-24 times depth, an lipped either d/8 or 1/4" which ever is larger.
But I'm remembering without reference before me, structural timber practice from 17th century boat & ship building, too.Occupational hazard of my occupation not being around (sorry Bubba)
I agree..I wasn't about to explain a locking scarf..he needs another plan
Spheramid Enterprises Architectural Woodworks
Repairs, Remodeling, Restorations.
Building permit? Engineer's wet stamped drawings? Both would be required to do this here.
-- J.S.
Is the roof going to be attached to the house on one side? If so, then just plaform frame the thing and X-brace the roof. No need for long posts.
I personally wouldn't do it.
Too much stress on that joint... too high up not to hurt someone when (note "when") it breaks... the issues just go on and on.
Either special order the things, use steel and build wrap it for looks, come up with a design that doesn't require that long-a posts... but I would not recommend trying to extend a wooden post vertically.
One more alternative
Perhaps (check with an engineer) block it up and then veneer with cultured stone, brick, etc. Might make a nice look.
Get some Al plate, about 1/4", argon-welded, into a two-foot long, square sleeve for each post to serve as a splint. Bolt it into both 6X6s and get a structural engineer's approval. Even so, you are pushing the limit and taking on great liability. At least with the Al, you will not have the same corrosion problem as with steel. Make sure the bolts are Al too. Far better would be to come up with a completely different solution, such as steel posts with a cedar cladding to look like 1X6s.
A scarf joint is a bad idea. Don't do it. Splice the post where it passes through the floor joists or ceiling joists. Use a simpson BC 6 connecter and block all four sides around the post at the splice. This is standard practice and no engineering is required. The post is still considered continuous if you splice it this way.
You don't need to do it that way. And it'll look top-heavy, too.
Much simpler to build the deck on the 6x6x16-footers, and then add on 4x4 posts to hold up the roof beam. These 4x4's sit right on the decking, toe-nailed to it. Place them directly over the 6x6's--this keeps your roof load transferring straight down--but they do not need to be attached to them. Build a structural handrailing such as a RR trestle form. This is a typical architectural detail up here, called Croix St-André in French. It will hold those 4x4 roof posts up plumb until the whole building falls down, and maybe beyond that....
BTW, I hope you're planning to put intermediate X-bracing on those 6x6's before you get all the way up to 16 feet. Use 4x4's let into the face of each 6x6 1.5" deep, and lag bolt each joint with two 3/8x5 grade 3 or better lags and big flat washers. Squirt some structural adhesive in there too, if you want to have a belt with your suspenders....
Dinosaur
'Y-a-tu de la justice dans ce maudit monde?
Dino-dude, If he were (or anyone else) in WNC {west north carolina}..where I was..it is REQUIRED to use 5/8 all thread or long hex head bolts, for wind bracing. Even if it's let in, lags were a no-no.
I wound up using a hole saw to create a counter bore for the nutz and washers..then a thruhole for the all thread.
Just FYI.
Spheramid Enterprises Architectural Woodworks
Repairs, Remodeling, Restorations.
Thank you, bro. Good to know. I prefer to use through-bolts myself, but I know most DIYers don't usually have beefy enough drills to go through big gnarly 6x6's without toasting the motor....
Trick I use to counterbore the bolt-heads and washers is to drill about ½-¾" deep (or deeper as necessary) with either a spade bit or a Forstner or saw-tooth (depending on size), then drill through the rest with a power auger. As I get near the other side, I slow down until the pilot screw just peeks out, then I back it out and counterbore from the other side using the pilot screw's hole as a target.
Dinosaur
'Y-a-tu de la justice dans ce maudit monde?
yeah man, same here with the pilot on the auger. When I made them log stairs my counterbores were so deep, I had to have a solid pilot made that fit my 1 1/2'' saw tooth type borer...it would then follow a 1/2'' through hole..just screws in place of the threaded pilot. An using allthread couplers for nuts I had to weld a reg. socket to a deep socket to have enough room for the bolt ends..sheesh, too much engineering.
I could just see a DIY using a 1/4'' crapsman drill with a 18'' long 3/4'' auger..lol...no, wouldn't work..need a 3/8'' chuck for that..
I gotta gain some weight, my 1/2'' RT angle keeps lifting me up..mebbe lead bars in the tool belt?
Spheramid Enterprises Architectural Woodworks
Repairs, Remodeling, Restorations.
Sash weights. :}
good plan...I got some somewhere.
Spheramid Enterprises Architectural Woodworks
Repairs, Remodeling, Restorations.
For stuff like that a boring bar is easier once you get the pilot hole drilled. Just run it through, set in the right size cutter, and turn the crank. It'll pull it's way right through dead effin' straight. This is how the 2,3,4, or 10'-long holes for keel bolts are put into boats....Dinosaur
'Y-a-tu de la justice dans ce maudit monde?
I don't like the half lapps and there is no need for it. Build the deck on the base posts, then start off again from the deck up to build the roof.
Check out the thread here parralell to yours about the deck collapse to keep yourself grounded. The deck should be let into the posts or built on top of them.
Think twice about each joint, analysing how can this go wrong, and don't assume anything.
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Talk with a welder to see if he can make a 4ft sleeve to fit around the 6x6posts with a dead stop in the center of it. Then have him make holes for thru bolts, after its bolted together trim out your posts with azek to hide the steel sleeve make sure it has a heavy coat of paint on it tho ( just an option to consider ok!!)
How about using square steel tube? 6 x 6, 5 x 5 or 4 x 4 could be used depending on exactly what size you thought looked nice. Extremely strong.
You can get pt gluelam posts long as you need em. Barn builders use them all the time.
I wouldn't splice a bearing post. Better to use one piece of engineered lumber. If not I agree with the poster who said to use steel columns and case them in wood. Much stronger and safer.