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+-- Thread: Lap Joints on Beams (/showthread.php?tid=7183059)
Lap Joints on Beams - photog - 01-02-2016
Greetings folks. I'd appreciate some opinions. I'm building an outdoor kitchen covered by a pavilion, which is a free standing open sided structure with a solid gabled roof.
I've built a small scale model.
The four 4x12 tie beams (apron), supporting the roof, sit atop 6x6 posts. My question is one of beam joinery where the 4x12s meet on the same plane at right angles at the corners. The beams will be let into the tops of the posts and sit on shoulders. The 6x6 posts allow for tenons to rise up on their inside corners to which the beams can be secured.
Additional fasteners and strapping will fully secure the beams to the posts.
This drawing should give you the full picture.
The drawing shows the beams half lapped at the corners and that is how I had intended to join them.
But there are options. I could go with a mitered half lap as shown in this example.
Keep in mind that I'm working with 4x12s, but the same concept as shown still applies.
Or possibly a vertical half lap similar to this one.
Model scale is 1 inch = 1 foot. Six inch WWF figures party in the model.
Can anyone site an advantage of one joint over another? Or possibly a better joint for this application?
Re: Lap Joints on Beams - Axehandle - 01-03-2016
Our ancestors used joints like the ones in the first CAD picture to build much of the town I currently live in. Those buildings are still standing today unless the were destroyed by fire.
Re: Lap Joints on Beams - cwarner - 01-03-2016
I think your initial thought will be plenty strong. I'd be inclined to drill from the top down through the joint and pin it with a large spike or rebar in addition to your timberlok lags. Overkill, probably, but I would feel better about it.
If you are just looking for other options, with timbers that size, check out timber framing techniques.
Re: Lap Joints on Beams - Roger A - 01-03-2016
Not much there to resist wracking. Will posts be sunk and set in concrete?
Re: Lap Joints on Beams - photog - 01-03-2016
Thanks. Yes, I'll lag down through the joint into the end grain of the post. The tenon will be screwed to the beam faces. Also, the 6x6 posts will be wrapped with 2x material with the outside boards extending up across the joint to the top plate, trapping the joint. I figure that joint will meet seismic standards.
Re: Lap Joints on Beams - mike4244 - 01-03-2016
I have built a number of post and beam structures.What you drew is exactly what I would build. Miters are lousy for post and beam,lumber moves too much to be able to have a nice miter joint stay that way.
Go with what you originally drew up.
mike
Re: Lap Joints on Beams - photog - 01-03-2016
The posts are through bolted to Simpson Wet set post anchors embedded in 2 foot deep footings below the slab. To resist wracking, if you look at the model, note the two diagonal knee braces on each post.
Here is how I aligned the post anchors before the slab was poured.
I built a frame and staked it around the sunken concrete tube. I bolted a 2x6 through the anchor and suspended it at my calculated depth and x/y location from the other anchors. Attached cleats allowed me to lift out the assembly and fill the tube and then drop and set the anchor in it's precise location. It worked great! The anchors are only 1/8" out of square over the 14' x 14' span.
Re: Lap Joints on Beams - cputnam - 01-03-2016
I guess I misunderstood - thought the roof was solid.
I'm guessing that you did not get a permit, otherwise you would be using the earthquake code required Strong Ties. At least that is the way it is down her in south end of the state.
Re: Lap Joints on Beams - Axehandle - 01-03-2016
BTW
That model is a thing of beauty.
Re: Lap Joints on Beams - photog - 01-03-2016
Thanks Axehandle, and to all who replied. Building the model helped me work out design unknowns. I've stood a few walls, but I'm far from being an experienced carpenter. Woodworking and carpentry should dovetail, but their are differences and it's not just tighter tolerances. I admire those who can build houses efficiently and well.