How to keep a gate from sagging
The problem with using wood as your support system is it will expand and contract everytime it gets wet and dries back out. Instead go ahead and build your gate to match the rest of the fence and then use a metal frame. I have an adjustable metal frame that can keep your gate from sagging or twisting. I am telling you that this is an item I sell on my website. This is an item we use on our own fences that we install so I know it works. The name of the product is Gate Sag Eliminator. The link is below along with a link to a good pair of hinges and a latch.
Gate Sag Eliminator
8 inch Strap Hinges
Post Latch
The problem with using wood as your support system is it will expand and contract everytime it gets wet and dries back out. Instead go ahead and build your gate to match the rest of the fence and then use a metal frame. I have an adjustable metal frame that can keep your gate from sagging or twisting. I am telling you that this is an item I sell on my website. This is an item we use on our own fences that we install so I know it works. The name of the product is Gate Sag Eliminator. The link is below along with a link to a good pair of hinges and a latch.
Gate Sag Eliminator
8 inch Strap Hinges
Post Latch