Recipes for earthen plaster abound. Some recipes use straw, some use manure, some cattail fuzz, and others add lime. Read a ton and learn, but remember the earthen plaster mix or recipe you end using is your individual choice. You’ll end up doing a lot of experimenting because the clay soils differ from area to area. So don’t get frustrated. Just remember to write it down after you figure it out.
I’ve collected some earthen plaster recipe options. Most of them provide some instructions on their specific procedures.
Recipe 1
3 (five gallon) buckets of sifted sand (sand sifted through a 1/8″ screen to remove pebbles)
1 bucket of mixed wet clay
3/4 bucket fresh cow manure
cattail fluff (see fibers in every handful of material)
8 cups of wheat paste
Recipe 2
4 Parts Clay (presoaked overnight in water)
4 Parts Sand
1 Part Flour Paste
2.5 Parts chopped Straw or Cattail Fuzz (straw cut into one inch lengths)
Recipe 3
This one is for rough coat:
1 part creamy clay slip (from site or mixed water and clay)
2 parts medium sand
½ part fiber (chopped straw)
Recipe 4
One part clay soil
Three to four parts sand
One-half part fine fiber
Enough water to make the plaster into a consistency slightly wetter than peanut butter.
This is just a small sampling of what’s out there. Clearly the recipes for earthen plaster differ, so experiment, experiment, experiment. For mixing the mud, save yourself some pain and get a mixing paddle that you attach to a drill. Professional mud guys wouldn’t be without this tool.
Smear mud all over the walls of your house. Really. It’s an idea whose time has come. Actually it’s an idea that’s been around for eons of time, but has been mostly lost to contemporary American culture. I know that the dry wall guys claim to be using “mud,” but I’m talking about real earth, real mud. I have to say I became a little more eager to entertain this possibility to do some eco-decorating when I started reading articles about how earth plaster can be used in ways that are similar to some of the current wall finishes and treatments; such as Venetian plaster.
“Many colors are possible, mostly in muted hues. Earthen plasters, with their slight–or major if you choose–variations in surface texture, reflectivity, and color bring a sense of life to a room or a whole house. They lend a handmade feel, often in a classic Old World sense. Some finishes look almost like leather or marble, but there is a lot of room for creativity. You can smooth and round corners and transform boring flat sheetrock by adding a bit of sensuous undulation or trowel or hand marks. Most people feel more comfortable in rooms that have some variation in wall surface, shape, texture, and color, perhaps because we humans have been housed for millennia in caves, and houses of wood, stone, mud and thatch–not in flat-planed boxes!”
Sounded pretty good to me; definitely worth some research. All plasters have to have three ingredients: a binder, an aggregate and some fiber. In the case of earthen plaster, clay (good old fashion dirt) is the binder, sand serves as aggregate, and the binder, well…it needs to be from some kind of straw and manure. The odor leaves when the “mud” dries. People experiment with all sorts of additives to make the mud easier to apply and more durable; things like wheat paste, whey and milk products, even cactus juice. Having grown up in Arizona, that last item seems like a stretch.
Now there are companies like American Clay that make a commercial product that is pretty simple to purchase and use. Somehow I feel like using this type of a product is missing the point. Even though this product states that they are an “environmentally friendly alternative to cement, gypsum, acrylic, and lime plasters,” the processing, packaging and marketing renders it not that eco-friendly.
So if I don’t go the prefab route and hire a professional to apply it, just how hard is this? More in my next post.
