steel swing gate question

"RHGrafix" wrote: I am drawing up a steel wrought-iron style gate, can anyone point me to a website that shows strengths needed for the components? (clip) I googled this but did not find answers. ^^^^^^^^^^^^^^^^^ I think one reason you didn't find a gate design website is that no one does stress analysis on something like a gate. First, the analysis would be sophisticated, and would depend on so many design choices that it would be difficult.

Build it so it looks like other gates, and you should be fine.

I am a retired steel erection contractor. I did a lot of wrought iron gates. I am not sure what you are asking re: the 3" pipe. Will that be a support pipe into the ground? Will this gate be hung from a pilaster? What do you intend to attach it to?

Fergeddabout home made hinges. Go to your local steel supplier and get the real deal. The hinges are the linchpin, and if they mess up, the whole thing can kill somebody.

More info gets you more info.

STeve

Yes, the 3" pipe will be in the ground about 12" and also embedded in a cement slab, 12" brick pillar around the pipe with 1/4" plate welded gussets bracing 3 hinges. Then I plan to get a mighty mule electric screw-gear for an opener/closer. I plan on using mild steel sq tubing and priming/painting it black. I am open to any ideas and/or websites showing the whole process. Thanks much! R. Hamm

You will need to anchor ANYTHING more than 12" into the ground. If you want something that will not flex at all, you will have to go up to about

4x4x.250 or greater. If there is any way to add a top brace and connect it to an existing structure, that will help rigidize it. You need to go at least 24" into the ground, and weld rebar onto the pole to tie it into the pour. I would go 36", and 18" square. Ten feet of gate creates a lot of flex and that occurs from the concrete line up.

I am sure there is an engineer to say what the minimum pole dimensions would be, but just do a three times overkill, and have the thing three times stronger than it needs to be. Plus, you will always have the kid that wants to hang off the end and swing like a monkey. That is a factor in the 3X R&D.

Steve

I installed a 9'-6" X 6' gate in Las Vegas last year, used 3"X3" .250 square tubing 2' deep into the ground. Actually it was a double opening gate in a

20' driveway. the posts flexed enough that the gates touched at the top where they meet and I had to go back and place rollers on the gate to keep them from flexing; next time I build a gate that big I will go with 6" square and/or anchor them from the top also. I honestly didn't think that they would flex that much, Live and learn!

Mike

I found one way to limit the flex if you find it difficult to go deep is to weld feet on the bottom of your hinge post. I had a 14 foot wide driveway and used three inch pipe for a three foot high gate. I had one chunk of scrap pipe running 18 inches underground across the driveway and one at 90 degrees running along the fence line. Each was about six feet long. These two pieces stopped the flexing in the ground. Randy

20' driveway. the posts flexed enough that the gates touched at the top where they meet and I had to go back and place rollers on the gate to keep them from flexing; next time I build a gate that big I will go with 6" square and/or anchor them from the top also. I honestly didn't think that they would flex that much, Live and learn!

Mike

If you look in the archives, there was a thread on gates and anchoring them last year, maybe 2 years ago. I recommended then and now you do NOT sink the supporting post into concrete. Dig a deep hole for a footing, fill it with reinforced concrete and place 4, 3/4"X18" long anchor bolts in the 'crete. Weld a heavy base plate to the bottom of the post with gussets to stiffen it and holes to match the bolt pattern. Install the baseplate post assembly with nuts and washers on top and below the plate.Then when, not if, the gates don't line up like you want them to, you can crank on the nuts to tweak the posts and gates into perfect alignment. You can't build it perfect so make it adjustable. Tom

You'd better download the installation insructions for the Mighty Mule opener and study them carefully. You'll find that the opener won't work with a 12" masonry wrap around your post. It requires 4 1/2" offset (approx) which will place the mounting inside the masonry. I've struggled with the same situation with a gate that I want on opener and a masonry wrap on.

Good point, I did download the installation manual a few weeks ago but did not notice that problem, maybe a different manufacturer of opener would work, Mighty Mule is most affordable though. Another way might be to leave a gap in the bricks for the opener hardware if it does not get too ugly! R.L. Hamm