Hi folks!

I’m a long time Lurker, been reading these forums almost every day. I’m not a timber framer (really interested in it though), so there’s really not much I can contribute, but I sure have learned a lot!

I’m wondering if any of you have ever supported wide overhanging hips on the outside of the building? I’ve been messing around designing roofs with wide overhangs, in this case 4’.



I’ve run the rafter ties under the beams and out to the common rafters which seems like it’ll give me adequate support, but the hips are left unsupported.



My solution are these double 2x6 knee braces that butt into the posts on the corner, and lap each side of the hip. Seems like it would be pretty easy to cut and install, but the weak point would be the connection (TimberLok lags) where they butt into the posts. Plus, they really don’t look all that nice.







Do any of you have a better solution?? I suppose I could use 4x stock for the hips, but these rafters are curved, and cutting thru 4x on a curve would be pretty difficult.

Not being an expert I will throw in my opinion so the experts may point out the errors in my thoughts.
The key problem is the screws do not offer the strength you probably need (shear off or tear out)
I would infill the 2x6 with a 2x5 or 2x4 with the edge flush on top and receesed an inch or so on the bottom (fancies it up a little) and cut to act as a shoulder on the rafter end and jointed into the post. Epoxied together would stiffen and strengten it considerably, or bolt it in recessed holes and cap with 1 inch dowels.

Bob

Bob, those TimberLok lags are pretty strong with great pull out resistance, and I have thought about what you suggested with using infill material between those two braces, and meeting up with the post, but I'm not really happy with my design idea. I'm hoping someone's addressed this issue before and has a more time tested, traditional soulution for me.

What program are you using to create this drawing?

I think you'll need to research some wind up-lift solutions to make this building safe.....

Jim Rogers

You're right Jim, I still need to get some engneering done. Do you see any obvious issues with uplift I should address?

I'm putting the posts in to the ground for lateral stability.


I use SketchUp for these drawings!

I just created a 3D PDF of this pavilion that you can zoom on and rotate around, so you can poke around in it if you'd like. http://www.woodsshop.com/Misc.htm

sure would like to hear any observations or suggestions!

Using braces like that is certainly within the realm of possibility.

I'd try and put in a more positive connector than a pair of timlocks, however. Uplift can be a big concern; the the framing style should be able to handle it, just so long as everything is connected well.

Depending on where you are at geographically, post anchorage into the soil may be a bigger deal than anything, to keep the thing from pulling out or overturning. If the wind isn't too bad, you might be ok.

The thing that jumps out at me is there is a lot weight / surface area high up in the air, without a lot of bracing. Wind or seismic lateral forces could really get this thing to twist unless those posts are REALLY stiff.

Certainly will be neat looking, and, looks like you can really can make SketchUp work for you.

Joe

J.W. I have run into this on occasion. The braces up to the hips are a good start, but I concur with the opinion that the timlocks are inadequate. The problem with a roof like this is that only 1/4 of the weight is inside the square formed by the posts. (3/4 of the roof weight is outboard of the posts) I have solved this in the past by creating a heavy structural fascia along with heavy braced hips. I also have some concern regarding overall stability. My philosophy on exterior structures is that parts near the ground will need to be replaced someday. It is more work up front, but I recommend not sinking the posts in concrete. Design a post base connection that allows the post to be replaced in the future. Good luck.

Hey Joe, you know, I haven't really considered the posts pulling out .. is this really an issue when they're down 4' or so? You're right though about there being alot of forces high up without much bracing. This real wide 4' overhang is just something I'm exploring right now.

The posts are a little whimpy and undersized considering the racking that could happen. My other structures like these (with 2'10" and less roof overhangs), which are a little bigger in footprint, (10'x10' , 12' x12') all have 6x8 posts instead of the 6x6 I show for this one.

Not Trim Lock, but TimberLok lags. Haven't you heard about these? They seem pretty good to me as a Builder. I thought Timber Framers were using these alot these days?


I put some Technical Info and Specs about them that you can go download and view on this page http://www.woodsshop.com/Misc.htm

Say Joe, I've never run this corner connection by a Structural Engineer before, but could you tell me what you think about this post/beam connection? I'm trying to not use real visable connection hardware.




Chris, can you tell me a little more about those structural facias, and braced hips? Got any pics of either??

Oh, and that TLok pic I posted shows 4" thru 10".