how would people attach corbels to gable end rake roofs? The Corbels would be somewhat structural. The roof has a 30 inch overhange and outlookers set back 24 inches into the roof back to teh first rafter. Most fo teh gables are stick framed with 2 x 12 rafters and on section is framed with trusses. For information, the truss designer was not concerned about the over hang and an engineer causually said the lookouts alone could be fine (or words to the effect).
I want the look of the corbels and think a bit of structural support would not hurt. Therefore how would one attach the corbels. There are at least three different senerios here.
1. At the peaks, directly behind the corbel is a 6 by 6 post and on top of the post a glulam beam. So for the most part through bolting is not an option.
2. At the low ends of the gables, behind the upper portion of the corbel would be rim joist (could thicken with block if necessary). At the lower part of the corbel you have the typcial corner stud configuration which makes for preety messing access for through bolting, but possible.
3 At a point half way down from the peak teh attachment points can easily have blocks added between studs for eitehr through bolting or could one use long screws (oleaugs -spelling) through from behind. At teh truss peak you have similar blocking as part fo teh truss vertial post.
Any thoughts. Thank you so respectfully.
Replies
The Timberlock could be run into the bracket back from behind. One guy driving the screw outwhile another guy holds it in place. That way no hole to patch
Thanks for the vote for Timberlox
I think it would be tough to screw into the back of the brackets at teh corners of the buildign with all the studs built up there for the corners. Might be able to do it.
When you suggest Timberlox (timberlock?) are you thinking that they have enough structural shear and pull out strength to make the brakcets structural supporting, or thinking of the brackets as ascthetics? I think my application is a bit of both given the relatively large overhang.
Just curious as to your thoughts.
Corbel/bracket/corbel ... bracket ...
Yes, Corbel or bracket. I have never figured out what to call them as on person gives you blank stares at the one word and others at the other word. Some have even called them purlins.
So, ok brackets it is as I am with you as to corbels being more for interior support of counters or shelves, although I have seen "corbels" support flat roof projections, etc. So, yes I am attaching triangular brackets which do have a space between teh vertical arm and the diagonal support piece.
What do you mean by "not part of the structual design"?
As for structural support, if there are any structural forces at play, for the most part they are downward due to roof and snow loads, so a bolt or lag would be in shear. However, I suppose there would be some of tha force translated in a way to tend to pull the bracket away from the wall and therefore I was thinking through bolts. A lag could be pulled out. Now at the peak, I have little choice as I have the end of the 18 to 22 inch deep glulams directly behind the top portion of the bracket and a 6 x 6 post down lower. So lag into the glulam, which is end grain which is not the best, but then again at the peak there should be very little load on the bracket.
If I can lag bolt from behind is that better than from teh front? Would several timberlox screws be better than lags? Any thoughts?
I've done just what you mentioned. I mande the corbels from 4" X 4" PT, morttsed and lag bolted together. We lagged them to the truss top cord and webs as we could. We used them to take the sag out of a too deep overhang and they've worked as panned for 10 years now.
Did you lag from teh front or back?
Did you lag from teh front or from teh back?
Thanks Florida.
From the front. We drilled a recess for the bolt head and ran them in to the depth of the trusses.
Star-Drive Lag Screws
Assuming that you have access from the back, here is an excellent choice for your application. These are rated for shear and pull-out, written results are available. You will have no problem penetrating one or two corner studs prior to the corbels, as the screw design and deep recessed head deliver outstanding torque to the fastener, and they are available in a wide variety of lengths.
Attaching brackets
The same company that makes Timberlocks also makes Ledgerlocks. They are thicker, stronger. We've used them for years to attach roof brackets (and anything else where it seemed appropriate). No predrilling needed, usually rattle them in with a small impact driver.
I'm pretty sure I've read on the box they are engineered to have comparable sheer and pull out resistance to 1/2" lags. But they have a very small head...maybe 1/2" diameter round with small (maybe 5/16"?) hex. They come in black or grey. We use them all the time and leave them exposed, or countersunk and plugged like someone else mentioned.
If 2 or 3 of those bad boys won't adequately support your brackets, you have bigger issues than how to attach.
number of t locks or ledger locks
Having read that same box a bit more carefullly, I think that we need to add a few extra of the little guys instead of a one to one exchange. If I recall it is closer to 2-1 or 3-1 for the same loading. Still a lot more economical than usng the lags and all the extra labor involved. The finished appearance is a lot cleaner in my opinion. For a nother option look into Headlock screws, same manufacturer and shaft size, just with a larger more washer like head.
Hey Jim long time no jabs. HOpe things are well with you!
Hah!
Yes, long time indeed. I was grinning ear to ear when I saw your name there. We get GWC, Patrick and Adrian back we'll be well on the way to a reunion slapfest! Maybe Chuck Crawford in Oklahoma.
We're all great out here. Hard to imagine a life better than what I live.
How's everything with you?
Ha Ha
So glad to hear you're doig well!
Still bending nails and stuff. Driving that old white Ford 250, told you it would last. Hoping to get to the happy this year!
I was HAPPY to see your name on here as well, oh the good old days! I hear the good new days are not to far off though!
Thanks to both Jims
Thanks Jim and you too Jim.
I like your confidence in the screw idea (if 2 or 3 can't do teh job you have problems).