Hello:
I’ve got a 6×6 post that divides my 19′ garage door opening that I need to anchor to the concrete below. I was planning on building the post out of 2×6’s with a PT plate, and using a 1/2″ simpson retrofit bolt, as I’ve got some extras from other remodeling work. The top of the post will be tied into a 4×12 beam. While the simpson bolt will hold the post down it will do little to prevent twist.
I’m planning on 2 pairs of carriage doors for the openings, which means large doors will hang on both sides of this post. I’m imagining that if a strong wind ever caught these doors they could very well torque the post.
Any suggestions for how to eliminate the possibility of twist? How about 2 simpson retrofit bolts? There’s not much space though.
Many thanks in advance.
Andrew…
Replies
Do the doors have to hang on the center post? Why not on the other side of the openings?
They will hang on both sides actually--there will be 2 sets of double carriage doors.andrew
How about replacing that post with a square steel tube instead. Wide flanges welded top and bottom to counteract what ever twist you think will be applied by the doors. The bottom flange can be flush mounted in a new footing or simply buried in a pour. Top flanges can be saddle style to prevent twisting of beam.
The concrete is already poured. So I need a way to mechanically attach the post at the bottom.
"Ineed a way to mechanically fasten the post at the bottom..."
Use "Quick Bolts" by Hilti. Use 3/8 or 1/2 inch dia by whatever length you desire..they come in sizes from 3 inches to over 12 inches in length. 4 inch length would work just fine. Drill the appropiate size hole with a hammer drill, then insert the bolt in the hole, and then tighten...that's all there is to it.
I'd go with a steel column...be it square tube or (better yet) an "I" Beam. I would have steel flanges welded to the top and bottom. Use quick bolts in the concrete for the bottom flange and use lag bolts to secure the top to the existing header. Pad the beam out to whatever final dimension you like using lumber, and attach your garage doors into the wood.
If you don't like the quik bolt idea, go to Hilti or to Fastenal and buy some 2 part epoxy (not cheap). Drill your holes, fill with epoxy, set your bolts in place and next day, when epoxy cures...voila!
Just so you know, this epoxy is rated for over 15 ton pull-out...and believe me it works! But for your needs, quick bolts are plenty strong.
Davo
Jack the header just a twitch and get the post under it so that there is some weight on it. Mechanically fasten as appropriate. Then lock the bottom into the floor with a pair (or three) of Simpson HDs pinned into the concrete.
Are there any appreciable advantages of the Titen HDs over epoxied retro-bolts? Or is it that you can fit more of them into a relatively small space?
Thanks.
Andrew...
I think either would work for your application. GRK also makes a similar bolt called a Caliburn screw, similar to a topcon (which I hate) but looks much more rugged. I've seen samples of the GRK bolt on the counter at my lumber yard but haven't actually used it. You don't need malny bolts for your application, escpecially if you can get some weight down on the post. I think three bolts would be work fine, one on either side of the post and one in the middle on the inside face. I'd think that to many bolts holes in one small area might even weaken the concrete in that area.
Your options are pretty broad....many of the off the shelf post bases will securely hold the bottom and prevent from twisting, at least the ones where the metal wraps up around the sides of the post. Many of them using a single bolt to the concrete don't attach to the concrete in a way that keeps the post base locked in place as the post twists, but can be helped along with a few tapcons. The shear on a tapcon is rated quite high.
Another approach could be to simply use a wide piece of 1/4" angle iron bolted to the concrete so the post can sit on and be separated from the concrete by one "leg" and through bolt the post to the side of the metal with a few horizontal bolts. Very solid and pretty cheap if you have a metal supply close by. It's such overkill that I'd bet most inspectors wouldn't question the connection. For oddball things such as this I normally cut a section of the right size from a wide-flanged beam scrap with 7" grinder and cutoff wheel. If the cut is made carefully it looks quite professional with minimal cleanup of the edges.
Along the same lines, the "H" profile of the wide flange beams makes it ideal to cut various shaped attachments, reinforcements, etc. that typically would require a welder. Many carpenters avoid such things thinking it takes too much time, especially looking at a beam a foot or more deep with flanges nearly a half inch thick, but a cutoff wheel in a grinder can make short work of these smaller cuts. Even a sawzall and sharp blade can cut the web surprisingly fast.
The key to making it cost effective is starting out with a good sharp outline of the part on the beam and make the cuts straight and as clean as possible so they fit properly and require minimal sanding of the edges to look professional. Drill any holes before cutting out the part since it's always easier when it's still part of the heavy beam. Drilling holes in heavy steel is quite fast if it's held in place and sharp bits are used.
Best of luck!
Beer was created so carpenters wouldn't rule the world.
Interesting ideas on using the metal. Would you happen to have any pictures?
<!----><!---->The situation that comes to mind and always seems to pop up is a short post that needs to be firmly anchored on a rim joist, such as for the end of a pony wall or stand alone newel post. Of course this fix only works if the base of the post is wrapped or otherwise conceals the bracket.<!---->
<!---->In the bracket below the 7/16" thick flange of an w8x28? steel beam is pretty stiff and the 5/16" web makes a built in angled leg to the bracket so we can simply bolt or screw into the post, rim and floor joist.<!---->
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Beer was created so carpenters wouldn't rule the world.
Edited 9/1/2008 4:21 pm ET by IdahoDon
Thanks for the detailed response. Nice ideas about modifying existing steel beams to create mounting brackets.FYI: I found an off the shelf 6x6 post base from simpson, a u-shaped profile that has 2 holes at the bottom for 2 retro bolts. Downside is that it's a canada-only product. All the US versions have only 1 hole. Go figure.I've decided to redesign the wall by making the center post a bit wider. Now it is 6x9. This actually works better proportionally with the rest of the wall and provides enough extra space to more comfortably fit 2 retro bolts.Thanks again for the good ideas.Best,
Andrew...