Arena base question

We live in the maritimes (east coast of Canada… very wet climate!) which is making me miserable because I can almost never actually ride my horses! and I have 3 two year olds to start under saddle next year so I’m pushing for a small arena.

We have an outdoor grass ring that is already leveled, with ditches around the sides of it so it drains decently. Our soil is primarily clay. The one groundwork guy that I had out to discuss the arena plans with said we would need to have the sod removed, pack the clay, and put the sand on top of that. I was expecting (having gone through the arena building process with my parents who had put up an arena up back in Alberta and had to pack clay, bring in gravel, pack that down and then finally put sand in on top, and they’re dealing with a pretty dry climate overall) we would need some sort of gravel/crusher dust between the clay and the sand but he didn’t think that was necessary and has done another arena in the area without it and no problems. Your thoughts? I’m happy to not have to spend more money on stone/crusher dust if I don’t have to, but also don’t want to end up losing my sand into the clay because even though this site drains well, we still live in almost constant rain.

I’d do the gravel base because better safe than sorry.

Doesn’t sound right to me, and I’m in the wet SW Washington State area with clay soil as well. We had to pack the clay, then install a base of crushed rock, then footing. I can’t imagine the clay topped with sand would work. Can you go visit the other arena this guy did? Sometimes, I think people think something works because they don’t use it! I’d want to see the same plan in action and actually being used, and how it held up over time.

The one ring here that I’m familiar with that the contractor (not an arena guy) did not install a rock base in between the clay and footing was an indoor with shredded cedar for footing. Looked wonderful, but worked horribly! Horses would fall down because the footing would literally slide across the clay and there was no grip. I can’t imagine how bad that would have been if it were outside.

If you search, PNWJumper has some posts about her arena and the layers she used, which seems to have done really well in a rainy area. Better to do it right the first time than have to go back and fix it.

We took off the top soil, added stone dust and compacted that, and then sand will go on that. Right now we are working on about 3 inches of UN compacted stone dust