joining two beams on a post

bengreco · 10-10-2011, 06:39 PM

In building my patio cover with three posts and two beams, how do I join two 4" x 10" beams at the center post? Also, the two beams will be meeting at an obtuse angle (about 140 degrees).

woodworkbykirk · 10-10-2011, 07:00 PM

i would do it as a 3 ply 2x10 beam instead of 4x10. this way you can offset each joint so you can through nail while alternating how each ply lays.. it will make is stronger. also you can get skewed connectors. a simpson strong tie LA-90 should do it.. its almost the same as a L-90 except you can set angle it to whatever angle you need. this is use in conjunction with regular fastening

if you still are going to use 4x10 use lag bolts

**kwikfishron** · 10-10-2011, 07:02 PM

I’d have a post to beam cap fabricated and send it to the galvanizer.

wombosi · 10-10-2011, 07:35 PM

maybe a half lap joint with diagonal braces. how big are the posts?

**kwikfishron** · 10-10-2011, 07:45 PM

Quote:

Originally Posted by wooworkbykirk

i would do it as a 3 ply 2x10 beam instead of 4x10. this way you can offset each joint so you can through nail while alternating how each ply lays.. it will make is stronger. also you can get skewed connectors. a simpson strong tie LA-90 should do it.. its almost the same as a L-90 except you can set angle it to whatever angle you need. this is use in conjunction with regular fastening

if you still are going to use 4x10 use lag bolts

That’s all fine but how are you connecting the beam to the post?

Daniel Holzman · 10-10-2011, 07:51 PM

Without a diagram, it is difficult to visualize exactly what you are doing. However, it is unusual in residential framing to connect two beams over a post, generally each beam rests on the post via a notch, and the beams are not connected, i.e. they are independently supported. By independently supporting the beams, you have a simple beam connection. If you actually connect the beams together over the post, you have an indeterminate connection, which leads to complex loads on the beams.

Beams that are simply connected have zero bending moment at the post, while beams that are continuous over the post experience negative moment over the post, which is not usually accounted for in standard design tables. I suggest you consider the previous suggestion of using a Simpson type connector, which will allow each beam to be independently supported. Of course, I am assuming you got the beams designed, hopefully you are not guessing at the required size of the beams. There are unlikely to be any standard tables for your design, so this leads to wonder, if you got the beams designed, why did the designer leave out the crucial detail of how to support them?

10-10-2011, 06:39 PM	#1
bengreco Newbie Join Date: Oct 2011 Posts: 1	joining two beams on a post In building my patio cover with three posts and two beams, how do I join two 4" x 10" beams at the center post? Also, the two beams will be meeting at an obtuse angle (about 140 degrees).

10-10-2011, 07:00 PM	#2
woodworkbykirk journeyman carpenter Join Date: Sep 2011 Location: nova scotia canada Posts: 2,239	joining two beams on a post i would do it as a 3 ply 2x10 beam instead of 4x10. this way you can offset each joint so you can through nail while alternating how each ply lays.. it will make is stronger. also you can get skewed connectors. a simpson strong tie LA-90 should do it.. its almost the same as a L-90 except you can set angle it to whatever angle you need. this is use in conjunction with regular fastening if you still are going to use 4x10 use lag bolts

10-10-2011, 07:02 PM	#3
kwikfishron Mod Join Date: Mar 2010 Location: Kansas/Oregon Coast Posts: 4,749	joining two beams on a post I’d have a post to beam cap fabricated and send it to the galvanizer. __________________ A Picture Is Worth A Thousand Words Especially In The DIY Chatroom -NEW MEMBERS- Please include your basic location in your profile. Some of the answers given are specific to a Region or State.

10-10-2011, 07:35 PM	#4
wombosi Member Join Date: Apr 2008 Location: Western Masschusetts Posts: 574	joining two beams on a post maybe a half lap joint with diagonal braces. how big are the posts?

10-10-2011, 07:51 PM	#6
Daniel Holzman Civil Engineer Join Date: Mar 2009 Location: Boston Posts: 3,583	joining two beams on a post Without a diagram, it is difficult to visualize exactly what you are doing. However, it is unusual in residential framing to connect two beams over a post, generally each beam rests on the post via a notch, and the beams are not connected, i.e. they are independently supported. By independently supporting the beams, you have a simple beam connection. If you actually connect the beams together over the post, you have an indeterminate connection, which leads to complex loads on the beams. Beams that are simply connected have zero bending moment at the post, while beams that are continuous over the post experience negative moment over the post, which is not usually accounted for in standard design tables. I suggest you consider the previous suggestion of using a Simpson type connector, which will allow each beam to be independently supported. Of course, I am assuming you got the beams designed, hopefully you are not guessing at the required size of the beams. There are unlikely to be any standard tables for your design, so this leads to wonder, if you got the beams designed, why did the designer leave out the crucial detail of how to support them?

joining two beams on a post