My horses are popping the boards out of our flimsy vinyl board fence more regularly now and getting out. I've been looking into installing a strand of electric at chest height, but am not quite sure how to accomplish it with the weird shape of the paddock (lots of interior corners and gates). I'm also concerned about being able to ground it properly because the paddock is set on very dry soil and I'm in Maine so I'd need to think about freeze in the winter. I'd probably have to go with horseguard bi-polar fencing if I were to go the electrical route. To be honest, setting up an electric fence intimidates me a little bit too...I've never done it before and have no one to help me!
Has anyone had luck with other types of fence reinforcement on vinyl fencing, like no-climb fencing or PVC garden fencing? My horses aren't purposely trying to tear down the fences, they're just knocking out boards while reaching through for grass, itching, etc.
Electric fencing is the safest fence for horses. The whole point of an electric fence is to train your horses to avoid it. They soon learn "don't touch" ... Electric fence wire/tape/braid can easily conform to any shape of existing fence. If you can mount an insulator on it, you're good to go.
A strand of wire placed on the fence will keep the horses from the fence. Your area's biggest issues is grounding. Freezing weather isn't a problem. Driving ground rods 8 feet deep before hitting solid rock may be the issue. I would suggest at least 3 rods 10 feet apart connected with solid #8 bare copper wire be your fencer ground. If you can't drive them straight down, a deep trench for each is a passable solution.