A horse wash area is a wonderful amenity at a barn. It provides a place to clean your horse without a lot of setup work or making a mess. And a clean horse is a healthy horse. You can create a wash area inside an empty stall in the barn or in an outside space beside your barn. This article will describe how to build an inexpensive outdoor wash area, but the suggestions are simple enough that you can also incorporate them into a wash stall within your barn.
Select a Location
Start by selecting a suitable location for your wash area. Most people choose a space near their outside faucet so water will be handy, but that shouldn't be the first selection criterion. Think about drainage and runoff.
Soil, in and of itself, is not a good base for your wash area. Even on a grassy area, it won't take many baths with the weight of a moving horse for the grassy area to get churned up and turn to mud. A much better idea is to put down a solid footing that will last. You'll want an area of at least 8 feet x 8 feet-but 10 x 10 or 12 x 12 would be even better. You want enough space that you can move around your horse while both of you stay on the base.
Second, this location must be evaluated from a runoff perspective. Your wastewater will contain detergents, remnants of fly spray, grooming products, wound salves, and more. You don't want that runoff to flow into ponds, brooks, streams, and/or wetlands where it can harm other wildlife. You don't want the surface runoff to wash across your driveway and sidewalks, where it could form a slick surface that's dangerous to walk or drive on. And you also don't want it to wash down through your manure pile, paddocks, or gardens.
A good location for a wash rack is an area with good soil drainage surrounded by an area of grass or weeds that will catch over-spray and any runoff that doesn't drain into the soil without harming wildlife or creating a slipping hazard.
Build a Solid Footing
With the location selected, now turn your attention to the base.
Concrete. The most obvious material to use to build a base is concrete. Begin by digging a shallow footing area about 4 to 6 inches deep, building a form, and pouring a concrete pad. Pay particular attention to the two aspects of the concrete's surface: slope and texture. You don't want to finish the concrete pad level; rather, you want it to slope in the direction that you want the runoff to go. But just a slight slope is needed, perhaps 2 to 3 degrees (one-quarter inch per foot).
As for texture, you don't want a smooth surface like a basement or garage floor produced with a metal trowel. Rather, use a wooden trowel to create the kind of rough surface you would want on a sidewalk. Place rubber mats or stall mats on the concrete. The concrete's rough surface will provide friction and keep the mats from sliding. The mats will provide a cushion and also allow you and your horse to remain stable, reducing the chances of slipping. Without mats, the concrete surface is not only hard on the feet, but steel horseshoes can also easily slip and slide.
Pavers. Another approach that's easier and faster to install is pavers. But before putting them down, you need to assess the soil drainage. A soil percolation test ("perc test") is a good idea, but not absolutely necessary if your wash area will be used only infrequently. If the soil drains well, you could place the pavers directly into that soil, forming a square grid with each paver about one-half to three-quarters of an inch apart.
An even better idea is to dig out the area as you would for concrete, line the perimeter with railroad ties or 6 inch x 6 inch pressure-treated lumber, line the bottom with filter fabric, and fill the area with a half inch or so of crushed stone. (The filter fabric is not absolutely necessary, but it will reduce the degree to which the crushed stone is pushed into the ground from the weight of the horses.) Finally, place the pavers into the crushed stone while maintaining the one-half to three-quarters of an inch separation mentioned above. This approach provides a "catch area" for the runoff to be captured and to drain through the soil. It works well in areas where drainage isn't as good and provides more time for the wastewater to flow into the ground.