Towards a better gate design

Bill Lantry

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Hey, folks,

Every gate I've ever made, well, sags... :(

Over the years, I've tried various designs. I always make the "frames" out of treated 2x4 lumber, so of course they're heavy. Then I've attached various kinds of slats to them.

I started with butt joints on the frame. Of course, those lead to nearly instant failure. I've tried lap joints with screws, and then with screws and glue. More failure. I've let diagonals in at an angle... that helps, but makes the gate even heavier. The last one I made, I even used a through mortise and tenon. With glue. Still sagged. :doh: I really do suck at this... :rofl:

So I'm looking for a different design idea. I thought of welding some square tube, and attaching wood to that, but of course I still don't have a welder.

I'm looking for a design that looks good, isn't too hard to build, will take heavy use (dogs and kids, including teenagers who tend to close the gate with a swift kick) but is still light, and is not too expensive to build.

This should be easier! ;) All ideas and examples are welcomed! ;)

Thanks,

Bill
 
Bill, the easiest way to keep a gate from sagging is to reverse the diagonal member so that it runs from the top hinge to the bottom outside corner. Doing this will cause any sag to be resisted by the in-ability to compress the gate slats attached to the structural members. The conventional way of doing it (as far as most drawings I've ever seen) has the diagonal member going from the bottom hinge to the top of the outside edge. This causes the gate to sag as there's nothing to limit the diagonal's effective rotation around the bottom hinge.

That, or weld it up out of tube!:D

Or you could build it like one of Tod's doors, that should do it too. I think he posted a description a year or so ago.
 
I have gates built 10 years ago that haven't sagged and which use a diagonal going from the bottom hinge side corner to the diagonal opposite corner. Nothing else fancy. Half lap joints with screws/dowels to hold them in place with the diagonals just being laid into the frame as a tight fit across the diagonal.

Think triangles. basically a square or oblong is geometrically unstable. You can change the angles of a square without changing the length of its component sides. so before you know it your square has changed itself into a parallelogram. Putting the brace in gives you a triangle. You cannot change the angles in a triangle without changing the lengths of at least two of its sides. With a diagonal brace you have created a triangle between the hinge post and the top rail. By making that diagonal go from the bottom hinge side to the top opposite corner you make it so that the only way that the length of the side can be changed is by compressing the length of the diagonal. Wood doesn't compress that easily. The force of gravity acts to constantly close the joint rather than pull it apart. All you have to worry about then is decay!!

Man - who know that all that nonsense in trigonomics lessons would one day actually be of some use!!
 
I have built a number of gates that didn't sag but following the opposite advice given by John.

The gate can be built in one section, or larger gates with a horizontal mid-support can be built in two sections. The plan is the same, but for discussion, assume two hinges, and two horizontal members.

The bottom hinge is attached to the bottom horizontal member. A diagonal is started at the bottom hinge, with a point in the diagonal set into a notch in the horizontal member near the hinge (so the notch, not just nails, prevents movement). That diagonal goes to the upper horizontal member at the end away from the hinge... again in a notch. Now we have an upper triangle than cannot sag (even if the nails sag a bit). The upper horizontal is held fixed by the upper hinge and the diagonal to the lower hinge. Slap some slats on to hold all the boards on the same plane and you are done - you don't need to have many slats, or even touching slats for this to work.

If you use three hinges, and want to build the gate with upper and lower sections (three horizontal members), use the same pattern... the diagonal from the bottom hinge to far end of the middle horizontal. Then another diagonal from the middle hinge to the upper horizontal. All notched.

I have never found nails, screws, or bolts to be sufficient to keep a gate from sagging. A 2x4 in compression, held in place in a notch, holds a gate as well as it holds a wall from collapsing.
 
People have been building gates for thousands of years and the design that has won out is the diagonal from the hinge bottom to the top. This put the diagonal in compression which works better than having a diagonal in tension. You need joints which keep the diagonal in place and do not allow it to slip downward at the bottom. There's a number of ways of doing that - I, and others, can provide you with some joint examples if you need them.

Mike
 
This very thing was discussed in the past few days over on the Canadian WW'ing forum in a thread on fence building. Here is a link to page three where they start talking about sagging gates.

Basically, everyone there agrees with Charlie's most excellent advice. However there are also a pair of photos of two 15 year old gates that have not sagged, which would serve as a good visual aid to go with Charlie's comments.

best,
...art
 
On top of what has been said, there is also the old trick (that has nothing to with sagging) of puting the hinges on and inclined axis instead of vertical (as in old western saloon doors) this sistem makes the gate close by itself without the aid of any spring or whatever just using the gravity.

It is a simple and effective system that seems to have been forgotten, to make people buy spring hinges and other more complex devices to close gates.
 
I don't know how Ian has escaped. But one of the immutable facts of life is that the better you build a gate, the sooner children will swing from it and make it sag. :(
BTW, 16 foot farm gates are the mostest funnest for the kids to swing on. And even the heavy duty ones will eventually sag from that abuse.
 
A better gate design

I built a simple four foot wide gate utilizing two by two framing with a
two by four brace placed inside the frame running from the bottom of the
frame on the hinge side to the upper opposite corner of the frame on the
latch side. The idea being to transfer the weight of the gate to the bottom
of the hinge post. I then ran a long lag screw through the top of the hinge
post into the house frame itself to prevent the hinge post from beginning to
lean toward the latch post as time went on. I might add that I tightly fitted
the brace into the opposite corners of the frame. All components were
screwed together rather than nailed. I would guess that I built this gate
about 8 yrs. ago, maybe longer, and it has held up very well.
 
On top of what has been said, there is also the old trick (that has nothing to with sagging) of puting the hinges on and inclined axis instead of vertical (as in old western saloon doors) this sistem makes the gate close by itself without the aid of any spring or whatever just using the gravity.

It is a simple and effective system that seems to have been forgotten, to make people buy spring hinges and other more complex devices to close gates.
********************************************************
It hasn't been forgotten here in oil field country. Very common using 1" pipe or sucker rod. And if you want it to stay open just swing it open past the 90° point.
 
I also make mine of 2X4s. I lay the vertical members on edge and notch the tops and bottoms of these so that the horizontal and diagonal pieces will be flat and flush (diagonals are fom lower hinge side). Screw all together with 3" screws. I attach the pickets (or wire) to the horizontals and the diagonal(s) to keep all from loosening. Even 6' solid wood gates that I made many years ago are still straight.
 
I'm with Mike, the diagonal brace from the bottom hinge to the outbound top corner.
On the opposite side of the gate you can also install decorative gussets in the corners, but for a 4' gate the diagonal bracing should work.
 
Here's an aproximately 5 foot side door that I made for my wifes garden shed about 3 years ago. It is mortise and tenon joinery. To this day it has stayed the same as when it was hung.
Here are some of the shed details
http://www.superwoodworks.com/Projects/Shed.htm
BigShedDoopOpened.JPG
 
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