My contractor has started framing in the kickboards for my indoor arena. Right now the compacted base of limestone screenings is in. I am told that the next step is to put in the kickboards and then the final step is putting in the sand. My builder is building the kickboards so that they hover 4 inches above the compacted base. I am only putting in two inches of sand, so that means that the kickboards are going to be hovering two inches above the footing. This seems really dangerous to me. It seems like a foot could definitely get caught in there. Also, it seems like a lot of sand would migrate underneath the kickboards. Should the bottom edge of the kickboards be flush with the packed base? Or flush with the top of the sand? Ideas?
I have always seen kick boards that make contact with the footing -- no gaps at all. Sometimes there is a pressure treated 2x4 or 2x6 at the very bottom, but there is never a gap. This 'no gap' arrangement has been true in everything from Very, Very High End arenas to One Step Above Homemade arenas.
"Avoid loud and aggressive persons, they are vexations to the spirit."
- Desiderata, (c) Max Ehrman, 1926
Indoor arena, I would think no gap. Can not fathom why they would think it needs a gap? Outdoor arena, we do have a gap so water can flow out, otherwise we'd basically have a pond as water wouldn't escape. But even then the gap is pretty small, maybe a couple inches.
No gap. I had my contractor put a 1" x 6" pressure-treated board at the very bottom and then 3/4" plywood on top. I've seen a couple of older indoors (~20 yrs old) that had rotted out kickboards where it came in contact with the footing due to the moisture in the footing. My indoor is now 23 yrs old and no rot.
Back in my day, we didn't have as many warning labels because people weren't so dang stupid!
Yes, there is a 2x6 pressure treated board at the bottom, but its hovering about 4 inches above the base. I can see that you might want a little space in case the ground heaves with the frost, but 4 inches seems like a lot. I will definitely talk to contracter about this today before he gets too much farther.
The finishing touches are being put on my indoor arena as we speak. I am having a lot of discussions with my excavation/footing guy about how many inches of sand should go on top of the base. The base is 8 inches or so of limestone screened, watered and packed with a big vibrating roller. Under than is larger, coarser gravel which was also watered and packed. I want to start with 2 inches of sand as I figure we can always add more later, but taking it out is a pain. He is telling me that he usually puts in 4 inches, which seems likes so much to me! He is concerned that with only 2 inches of sand the horses will injure themselves when they hit the base and the base will get churned up and mixed in with the sand. Thoughts? I am a dressage rider if that makes any difference.
You can get ground contact 2x's, but it may depend on location, and you do have to ask for it.
Around here, it's no problem because so many bulkheads are built on the lake that suppliers near the lake don't even stock anything else. You can even get 2x6 T&G in stock because that's what the majority of the bulkhead walls are made from. They drive them in the ground vertically behind the rest of the structure.
Depending on the type of sand, 2" is the bare minimum. Upper level dressage or lower to mid level? At the lower levels 2 would probably be fine, but I don't know if it would work as well at the upper levels. Straight sand is fairly high maintenance as far as watering and dragging to keep an optimal surface. Much better with sand and an additive like rubber or fiber.
At home I have 2" of coarse river sand in my (outdoor)round pen over a compacted base. After a while I did notice that the top inch or so has been dug in to by my overly excitable mare. The round pen doesn't get very much traffic at all, just working the kinks out of a fresh horse that I don't trust to stay put if I come off. It is also HARD! Beach sand might give more cushioning though.
At the barn that I ride at (mostly dressage with a few hunter/jumpers), they have 3" of construction sand mixed with 2" of wood fiber footing. It is a little on the deep side, but not strain muscles and tendons deep. It also is cushion-y in case you have an unplanned dismount. The wood fiber keeps the sand from compacting or drying out too much.