Thread: gates for panel fences - what steel size to use?

I had to "fix" up aset of gates for a woman I know. They were made of 25 X 25 RHS and were nearly as big as yours. The bloke who built them wasn't much of a welder but the biggest problem with the construction was that the 25 X 25 RHS when covered with the cladding could flex and flop around as you moved them. I think I would use 50 X 50 at least just to get some stiffness in each gate. 2mm would be thick enough, because I think the bulkier frame material is the answer.
I think you would need to fasten the closed gate both top and bottom for security

For the gate post 2mm thick walled RHS would be okay, but it depends on how or if its to be connected into the rest of the fence. Given the size of the gate/s they will want to droop and if the post is not strong enough it will bend. Myself I'd be using a 4 or 5mm thick walled RHS. And as you're in Perth with sand soil I'd be burrying the post/s at least 600mm deep x 400 x 400.

50x50 x1.6 or 2mm in gal finish will be ok,its not the size of the tube but the desighn which counts.make sure you put a diagonal brace from top outside to bottom middle in each panel(even 10mm rod will do) to stop sag,use goliath or similar hinges and 90(or 89)mm x90 RHS x3mm or better 3.5mm gal for you post.THE MOST IMPORTANT THING FOR YOU TO DO IS PUT YOUR POST IN THE GROUND 600 mm,do not skimp depth and use proper concrete if you can get it,not quickset if possible.

Thanks All
I'll start ringing later today for some pricing on larger sized tubing, and suitable brace material. The brace would go from the top hinged side to the lower swinging side - correct?
I'd never heard of goliath hinges, but that style of hinge is what I was planning to use (the one with the 1/2" rod, captured bearing ball, and sleeves)

The post will be sunk a full metre into the ground (depth of my posthole digger) and set in standard concrete

I've read about people angling the post away from the gate by 1-2 degrees - should I bother with that? (so the weight pulls the post to vertical)

Regarding gate catches...
I was planning on installing a bolt into a pipe sunk in concrete for the center ground, and a main gate latch patterned on a cyclone gate which has a rod running from waist hieght to 300mm below the top of the gate - on this rod, two (or three) offset pins engage sleeves on the other gate creating lock points at 2 (or 3) locations. One of the lock points is where the padlock is fitted.

I'm planning on getting it done over the next fortnight, and will post pictures once completed.

Thanks,
Des

For what it's worth, 50x50 sounds a bit chunky to me (I guess it depends which side of the gate you see) something like 65x35 (assuming that exists) would look better. If it's too floppy, I'd add the same section as the diagonal.

As Daniel has stated, it's not so much the size of the material, but how it's designed with diagonal bracing. My two rear access gates, which each measure 1.5M wide X 1.6M high and are clad with 1.8M pickets and a 25mm x 150mm T/Pine plinth at the bottom are only made from 25x25x2.0mm Duragal, and the gates themselves have not sagged in 7 years. They're attached to 125mm x 125mm Cypress post in the ground.

gate.JPG

If your gate frames are clad with colourbond sheet, then this will help keep the gate itself square, and it's the posts they're attached to that will be the critical thing to get right. If the posts are stand-alone, they need to be quite big to stop them bowing under weight of the gates. If you can also diagonal brace the posts, then the post material can be much smaller. Also, if they are stand alone, angling them away from the gates will help, but how much depends on the weight of the gates, and the size and thickness of the post material.