Earthen Floor Start to Finish
The process of this floor has long been in the works. I first tamped the earth beneath the building. Then added a layer of cut polypropylene bags. Then 6 inches of red pumice ( otherwise known as scoria ). The scoria has insulating properties and also acts as a capillary break from moisture of the earth.
Through the scoria layer I added a 4 inch perforated drain pipe, in case one day a radon gas evacuating system could be attached. Then a couple layers of 4 mil plastic as air / moisture barrier. On top of that is 1 inch of of sand, leveled and tamped. Then tons and tons of mud. The mud base is at least 4 inches thick. A mixture of clay, crusher fines and straw. Crusher fines are usually cheaper than sand; it’s the step before plaster or concrete sand, so there is less processing involved. It has sand and rock all the way up to .25 inch. The diversity of the aggregate lends to a stronger substrate. This would have been a good time to add pex tubing for future radiant floor heating!
A few leveling layers of mud with finer sifted materials brought the floor ‘close’ to level.
Then 4 coats of alis (clay paint ) with fine sand and clay. I still had some left over red clay from a cut off the road near Albuquerque, so I soaked it and whipped it with the paddle mixer for a few days. The alis had 20% wheat paste mixed in for added durability. Then sponged it on, rubbing out any small divots in the floor. Hitting it with the pool trowel to work it in smooth. As it dried I buffed the floor out with a piece of cloth to remove any excess sand or debris. Swept and let it to fully dry before applying the oil.
In the interest of future estimation I’ve found that .5 gallon of linseed oil will cover about 100 square feet. That is, straight, with out mineral spirits. This is on a relatively smooth floor. The next coats were cut 20 -45 % with mineral spirits. In total I’ve placed 4 coats of linseed oil increasing the spirit content as I went along. The oil container was left to sit out in the sun for the day, so the oil was warm but not hot. The oil was applied with a paint brush with great success, sometimes dumping oil on the floor and working it around. The earthen floor really soaks it up. Especially to first two coats. Before I was done with the first coat of oil it was ready for the next. The linseed container says 12 – 18 hours before ‘dry’. The next day I added more. It didn’t soak in as much, but it added a shiny coat. Windows open and waiting… god that stinks.
I’m interested in alternatives to boiled linseed oil. The stink seams to stick around for awhile. There’s organic raw linseed oil with out the noxious ‘drying’ chemicals. Perhaps in the future I’ll try that. Linseed, Walnut, Tung, Hemp and Perilla oils are all hardening or ‘drying’ oils. They create a chemical reaction with oxygen, leaving a tough, elastic film. Citrus oil instead of mineral spirits may cut down on the stink factor as well. Remember! Rags and tools covered with oil can and WILL spontaneously combust.
After the oil has had time to cure, I’ll give it a coat of wax. I hear tell of a linseed oil, carnuba wax, beeswax, paste wax mix. Also a 50/50 linseed oil and carnauba wax mix. Straight linseed and beeswax. I’d like to experiment more with the super fine shiny finish. This time I’m going to use the Howard Feed-n-wax citrus oil and beeswax product for the final touch.