How long do you want it to last? A horse will eat hemlock very quickly. Some only munch on the top rails, others chew the middle of the walls as well.

It is a fairly soft wood, and if you have chewers, they may eat it. Horses that are stabled for a major portion of their day are more likely to chew - horses NEED to chew for a certain number of hours, seemingly, and will chew wood when bored. Some horses either enjoy wood, or have learned a "vice" and do it somewhat obsessively, rather like people who chew their fingernails. Other horses never chew wood.

As far as the tops of the boards go, you can cover the inside edges with metal, bent to a right-angle, or cover the whole of the edge with a right-angled-U shape. Hardware cloth can also be used, but must be carefully cut to eliminate sharp spikes. If you need stabling in a hurry, on a limited budget, you can plan to replace the hemlock with a harder wood as your budget allows. It SHOULD last for several years, and might last for longer, esp. if protected and painted.

Hemlock is actually a harder wood then either spruce or pine according to the barn restorer who worked on my barn. He recommended its usage. I used it in my stalls but did cover the top boards with u channel metal

I agree with bewdley. Hemlock is strong. So strong that a tiny branch on a hemlock tree will support a full sized man who is standing on it (hunting).My stall floors and dividers are made of 3" hemlock planks. My barn is 32 years old and I haven't replaced a floor board yet. My horses do minimal chewing on the tops of the dividers but they can chew any wood. The idea to cover with metal is a good one. Recently I saw a barn where the tops of boards were covered with rubber matting. I thought that was a clever use of extra matting and it didn't look bad either.

Bump!