Monday, June 1, 2015

Building a Better Gate, Part 2...

When you write a blog you sometimes wonder if there is anyone out there reading what you write. Once in a while you get a great comment on a post that just needs to be shared, expanded on, and appreciated. In an earlier post titled “Building a Better Gate...” I made a blanket assertion that the angle of a brace is more important than the direction.



When all other factors are equal, this is the case. But what other factors are there? An anonymous responder pointed out that the direction of the brace is often determined by the material and construction method chosen for the gate. Here is the text of the response:

On a metal gate, the diagonal should go from the hinge side high, to the latch side low. This is called being in "tension" vs. the alternative which is called being in "compression". Assuming that the welds hold, (which is an assumption that should be made), the question is whether the brace is more likely to stretch or compress, and compress includes bending. It will always take more force to stretch a metal brace, than it will take to bend one. That is why a truss rod works in one direction and not in the other.

On a wood gate, your braces need to be set the other direction, or in "compression". You cannot weld the ends of the wood together, and there are not great fastening systems for that. In tension the fasteners that are normally used will pull apart; in compression normal nails or screws will normally do the trick.”

I am going to agree, except for one very small point. Where the comment refers to “metal”, it is more correct to say “steel”. Aluminum can be a trickier material. It is prone to not only compression or bending, but it can also be stretched. So while an aluminum gate should have braces from the high hinge side to low latch side, a heavier aluminum gate may also need additional gusseting to combat the longitudinal stretching that can occur with aluminum.

The commenter goes on to make excellent points about the challenges of wood gate building and the need to use compression and gravity to help your fasteners hold the gate together.  All in all a great conversation about gate building.


Thank you to all who read these posts, and a special thanks to those taking time to set me straight!

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