Greetings.
First post.
Just completed a 12’x12′ pergola.
Precast tuscan hollow columns with 6″x6 structural posts inside. Structural column us anchored to concrete slab and to header with Simpson column anchors for application.
12″x8.5′ height.
6″X10″ headers with 4″X6″ rafters.
Structure wobbles.
Its not going anywhere. Client is concerned however and we desire to make them happy.
Is is possible to secure by filling interior of precast column with 12-18 inches of cement. My thoughts are that this will stabilize the base of the columns and reduce racking/movement.
Any advice out there?
Thanks in advance.
Charles
Replies
Welcome. Here's an old thread where they are filled with concrete.
http://forums.taunton.com/tp-breaktime/messages?msg=102646.147
Welcome to Breaktime. Could you add knee braces where the headers join the tops of the columns? That shouldn't look bad and it should help prevent racking. Other solution would be to add something at bottom of columns to prevent racking and that would show.
Others will be along shortly to post additional answers.
If you look at the link from JAlden there was rebar sticking up into the post before the concrete was poured in.
Without the rebar in the post you will just add weight to the bottom of the post. I don't think it will do anything.
Would they mind knee braces? You could make the braces fancy for them.
Will Rogers
how much wobble are we talking about? Anytime you have such weight atop of non-rigged flexible columns, you will have wobble.
I would guess that with 6x6 columns at 8.5 ft high, you should be reasonably stable.
Suggestion would be, to add stability if you haven't done this already, is to bolt through the beams at the top of the columns. I mean that there should be at least one bolt top and one bolt bottom at each connection location, through the whole assembly with a nut and washer on the other end and tightened well. You may be currently losing some stability at those connection points and this will work to resolve that.
on edit: I just realized that you may have connected the beams with anchors/ties and not have a physical overlap connection. if that is the case, you've made a critical mistake, in my opinion.
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I refuse to accept that there are limitations to what we can accomplish. Pete Draganic
Take life as a test and shoot for a better score each day. Matt Garcia
Edited 6/26/2009 12:51 pm ET by PeteDraganic
I see he says the headers are installed with Simpson ties. It would be much better if the headers were let in to the 6x6 and bolted as you say.
I agree with the others that the only way to fix now without taking the roof off and letting in the headers is to fashion braces at the top of each post connection. Probably going to have to mock up a fancy scroll cut to show them what you intend to do. I would laminate pieces to match header width and then scroll cut, glue and lag bolt into header and post. Its going to mean careful slicing on the column or sloppy cutting followed up by quarter round moulding. Going the extra mile you could plug the lag holes but then they can't be tightened so thats a trade off.
Good luck!
Thanks for the advice. We will investigate all options. Several lessons learned.Charles
Hey - actually the column anchoring thread was a stand-alone - here.
http://forums.taunton.com/tp-breaktime/messages?msg=105500.1
Forrest
Guys,Thanks for all the advice. Here is a shot of the finished project.Local cypress timbers.
Pacific Columns Edura Stone.
Cabot stain to match exterior doors on the home.Pictures below.Charles
Very nice looking work...
Whadja end up doing to stop the wobble? No knee braces, so assuming some kind of anchorage into conc below/ filled columns?
Curious, passed on an outdoor kitchen roof recently that I had similar concerns about, but with a homeowner that had the "just put it up on the 4 columns, it won't go anywhere" attitude. Didn't want to hear realistic/correct alternatives...Ahhh....no thanks.
Bing
We added additional concealed fasteners from rafters to header. Owners also specified a polycarbon roof covering (Polygal) that also stiffened structure. Owners did not want to us to retrofit anchors (read pay more money).Charles
Resized from previous post:
Edited 8/8/2009 11:18 am ET by rez
thanks for the resize - nice looking project!View Image bakersfieldremodel.com
Me too Rez, thanks for the resize. I can see it all at once now.
Nice job CG. Certainly one for the portfolio.
Runnerguy
I have studied the and studied this; the earlier link is the only way to go if you want this to be a work of art -- McDesign gives step by step -- takes time but it works - here is the link again http://forums.taunton.com/tp-breaktime/messages?msg=102646.147