heavy gate, help setting post

admin

I am getting ready to build a gate for my own driveway. I am going to build it this week. It is a single swing gate that is going to be about 16 feet wide by 7 feet tall.The main post that the gate is going to hang from is 4x4x.250 that will be set in cement.My question is about setting this main post. We live in the foothills of the sierra nevadas at about 2000 feet. We have heavy clay content in our soil. In the winter, we get real real wet here, and fence posts tend to loosen up in the ground.My plan was to just dig a big *** hole and use a lot of cement to set this post, but am concerned that in the winter it is going to want to move.Do you guys have any suggestions/tricks/tips for setting this post?My driveway and the surrounding area where this post is going to go is all dirt/rock. There is no concrete or asphalt.Thanks for the advice,RussMiller 302GMIller 12RC SuitecaseMIller 30A spoolgunHF-251D-1WP17 Tig torchSmith HD torchHypertherm 45Jet drill pressHF 7X12 wet cut horizontal band sawPlasmacam CNC table
Reply:Well I'm no expert on this, and that is going to be a massive gate (and that post sounds a little small to me), but I know you need to get the concrete well below the frost line if you don't want it to heave in the winter.This is a starting point:http://www.soundfootings.com/pdf/US_Map_Frost_Depth.pdfBut I would suggest consulting your local buildings department.
Reply:Either extreme depth to counter the leverage effect or raw weight to offset pound for pound. You need to calculate the weight of the gate 1st. Clay base, lots of late rain like we have now, little wind ==sagging gate. If it's close to flat the better would be a wheel at the end or a slider. But weight of the gate, caculate the weight of the gate, figure some for wind load."The things that will destroy America are prosperity at any price, peace at any price, safety first instead of duty first, the love of soft living and the get rich quick theory of life." -Theodore Roosevelt
Reply:Weld 2 ft long sections of 3" 14 ga(you could use scrap 4" if you have it left over from the post but its not necesarry to go that heavy) in line with the gate and in the opening direction. We called this crow footing a post. Use shims underneath the crows feet to get it level before you pour. You could extend the crows feet out further if you want to beef it up, or do them in 3 directions instead of two. Also, be sure to dig your hole in a 'bell' shape. Widening out at the bottomA 'Heavy Gate' can mean a lot of things. If its light ga tubing youre prob fine with your post as it is, provided you go deep enough for frost line consideration etc. If it has solid pieces or lots of ornamentation, consider filling the post with concrete and 2 pieces of rebar, then welding the cap on afterwards. Use a piece of conduit to keep the hinge holes free(if youre using thru-bolt hinges, which are handy for taking out gate sag after hanging without shimming/rewelding etc)Dont use a GTO operator. Use a Liftmaster.
Reply:If the ground is level I'd put a dolly wheel on the latch end of the gate. If not I'd set some angle braces on the gate post in the ground w/ concrete. One in line w/ the fence and one opposite the gate when it's open. 16' is a long gate to swing on a post unless it's really light weight.                                  JMHO,                                              MikeOl' Stonebreaker  "Experience is the name everyone gives to their mistakes"Hobart G-213 portableMiller 175 migMiller thunderbolt ac/dc stick Victor O/A setupMakita chop saw
Reply:All of the above, and, cast the concrete pier to extend below the frost line and with a smooth column so that frost doesn't have a "mushroom" head to push up on.
Reply:I'd just design a footing to include rebar with chairs that spreads the support of that main gate pole both vertically(digging down) and horizontal. Also so that the gate doesn't sag or cause to much lateral pull on the post use a nice suspension rig wheel on it. One of our members here posted a nice gate that had a tire/suspension thing that looked very impressive.
Reply:a 6 foot x 6 foot x 6 foot hole will hold eight yards of concrete, couple mats of #4 bar top and bottom and you  should  be good to go...
Reply:Originally Posted by weldbeada 6 foot x 6 foot x 6 foot hole will hold eight yards of concrete, couple mats of #4 bar top and bottom and you  should  be good to go...
Reply:I'm not an expert on this by a country mile.  And I'm not an engineer.  And I've never been to one of those Holiday Inn Expresses.  So take these as suggestions from an idiot.But I'd have a two pronged approach.  One would be to go deep -- twice as deep as your pole is high, if you can get an auger (maybe whatever people use to dig wells) to come in for the day?  And add a horizontal arm to your reinforced concrete piece as well?The other prong would be to have a solution to problems if/once they occur.  Run a diagonal cable from the top of the pole to a good footing an equal distance away from the pole as it is high.  Use a huge turnbuckle so you can fight the force of the gate with a constant stress in the other direction.  Along the same lines, make the hinges from the pillar itself adjustable so that you can correct for sag/droop/leaning over time just by adjusting the lower hinge out or the upper hinge in.These are available for rental, tow behind your truck, and with extensions can go pretty deep.Jack OlsenMy garage website
Reply:What about digging a trench and building the two posts as an assembly with gussets that are below ground.  See pic.  Jay DavisAWS-CWIC-60 Specialty Welding ContractorLoving husband, and father of two boys (
Reply:Originally Posted by highplainsdrifter. It is a single swing gate that is going to be about 16 feet wide by 7 feet tall.The main post that the gate is going to hang from is 4x4x.250 that will be set in cement.
Reply:Originally Posted by jbyrdWhat about digging a trench and building the two posts as an assembly with gussets that are below ground.  See pic.
Reply:Originally Posted by jbyrdWhat about digging a trench and building the two posts as an assembly with gussets that are below ground.  See pic.
Reply:Originally Posted by mla2ofusThat'll work good 'til you swing the gate 90* to open it.                                                   Mike
Reply:I build pipe fence all the time  plus i am an rancher tooo.  How long is the 4x4 post is???  My rule of thumb is a 8ft post will have 3 ft n ground and 6 abouve for normal use.  In your application for such a heavy gate i would recome haven at least 3 n half to 4 ft in ground with 12 in hole with cement but the cement needs to be around 6 inches below soil line. to prevent them from poping out.Of course I don't look busy.....I did it right the first time!
Reply:I agree with all above. If you dont add the cross piece underground, you can still weld angle or rebar to the post which will be set in the concrete underground.
Reply:Originally Posted by oxygen454I agree with all above. If you dont add the cross piece underground, you can still weld angle or rebar to the post which will be set in the concrete underground.
Reply:You could mount it like a light pole with a flange and four studs with adjusting nuts.  Then make a shoe to hide it.  That would allow for adjusting in the future when it sags.My name's not Jim....
Reply:Originally Posted by White Trash My rule of thumb is a 8ft post will have 3 ft n ground and 6 abouve for normal use.
Reply:Check this gate out that one of the members here built. Very nice thread.http://weldingweb.com/vbb/showthread.php?t=51536