I am going to say they probably won't stay flat without good base preparation. They have to lay level, to stay level, flat, under a horse. Do get the heavy mats, weight tends to keep them down better. Bigger pieces will give less places to come unconnected.
We were given a bunch of the 2ft squares that interlock. However they are not thick, maybe 3/8". Buyer hated them because they could not keep them flat under a horse. We have found a lot of uses for the free squares, but none of them are under horses, way too light to hold themselves down.
We used the HEAVY interlocking stall mats that we ordered thru tractor supply. They work great, but as with any stall mats you do need to start with a level base. We used screenings under our mats. THey are bigger than the 2 foot squares the previous poster mentioned and HEAVY. They make 10 x 10 "kits" and 12 x 12 "kits" Our only real problem is that our stalls are 10 x 12, so we had to use 10 x 10s and add other matting for the last two feet. At the time we got them, 3 yrs ago, we got the best price thru tractor supply and since we ordered 9 stalls worth, we got a 10% discount. BUT they won't deliver to you, so you have to have a flatbed trailer to get them home (they did load them, but unloading was a pain!)
They interlock really easy ----- that means they UN-interlock really easy. I bought 11" 80# test plastic ties and tied them together. The ties are cheap so use them liberally if you go this route.
I tucked the excess of the ties underneath, thru the holes in mats because I could see blisters coming really fast to cut all of them.
I put 4" of limestone crush down first, and let me just say my stalls are not that level. I eyeballed them but being over 60, wear a backbrace and a short female, those stalls are not level - lol
Tying the mats together keeps them in place and keeps the horse from kicking one up over another when they get up.
I've only had them around 5 weeks, but so far things are great. If they hold up for two years they will have paid for themselves in shavings savings, not to mention the time I won't have to spend deep-cleaning stalls every Saturday morning.
I put 2"- 3" shavings on top of the mats The urine filters down thru the holes into the limestone like it should and my senior arthritic horse is a lot more mobile than he was before the mats were down.
They look heavy duty and the price seems reasonableish. How big are the squares/rectangles? Thanks!
Yes those look like them. I got the 10 x 10's and the rectangles are different sizes, not "uniform" I think there are four pieces for each stall, I would have to measure each pice to give you the dimensions. THye do stay in place unless some bedding gets under the edges, then you can get some separation. Since my stalls are 10 x 12 we do have that problem sometimes and have to pull up the mats and clean out the bedding if it does get underneath. My cost was a little cheaper as I got the 10 x 10's plus it was 3 years ago. My old barns had heavy 4 x 6' mats but they did not interlock and had lots of problem with them shifting and getting bedding underneath. These do NOT shift at all and if your mats fit your stalls perfectly you shouldn't have a problem with bedding getting underneath. I really like them alot.