Rammed Earth Flooring Guide

Rammed Earth Flooring Basics

Perhaps the original eco-friendly flooring option, rammed earth floors— or "dirt," as it's sometimes more commonly known — have recently undergone a bit of renaissance as they've begun to re-enter mainstream consciousness. Though their specific ingredients and construction vary by location, the idea is the same everywhere: Take some dirt (with some clay content), add water, some stabilizing agents like sand and straw, and squish it until it's hard. Once dry, seal it with an oxidizing oil like linseed or hemp oil, and enjoy.

Pros of Rammed Earth Flooring

Perhaps rammed earth's greatest advantage is the material used to make it; the dirt used to create is available everywhere and inexpensive, and so there is very little construction waste involved. Because most of the production is local, rammed earth has 90 percent less embodied energy than concrete, while being just about as durable. It's also easy to maintain and repair — just add a bit of clay — and can be swept and even mopped (and, contrary to what some might think, rammed earth floors aren't dusty). Rammed earth also has great value as thermal mass— so much so that some entire homes made of it need no supplemental heating or cooling.

Cons of Rammed Earth Flooring

Installation of rammed earth flooring is quite labor intensive, and, because it's still coming into its own as a material, not all local contractors have experience working with it. Very high traffic areas will wear more quickly, and so might require some supplemental support, like flagstone, to keep it from wearing down too quickly. It's softer and more vulnerable to scratching and gouging than cement or tile, though it can be repaired (unlike other softer materials like linoleum). Like concrete, it's often impractical to use it for multiple floor dwellings unless the whole structure is made of it. Lastly, it often requires a bit of experimentation to get it right, as there is no foolproof formula for constructing the floors that works in every climate or locale.

How Green is it?

Rammed earth might be the greenest flooring material out there. It uses local materials, creates very little or zero construction waste and pollution, and uses very little energy during its construction. It's finished with safe, non-toxic materials, is very durable, and is a great source of thermal mass.

Where do I get it?

Walk out your back door with a shovel, and you'll have most of what you need. Seriously, most rammed earth flooring at least starts with dirt found near its eventual home as a floor; you'll need more help with labor than you will with materials.

Where do I use it?

Rammed earth flooring is suitable for most any situation, with a few considerations. It's probably easiest to integrate it with new construction, when it can be used for entire structures, or pretty serious renovation, when you're going back somewhere near square one. If used in very high-traffic areas, some reinforcement might be necessary, and if used somewhere with very high moisture, like the bathroom, it might need more frequent resealing.

What does it cost?

It's tough to express this cost in dollars, since you'll be using a variety of materials that will differ by the job. Rammed earth flooring is generally inexpensive for the materials, and more expensive for the labor, if you have to pay for it.

Can I install it myself?

Yep, but prepare yourself for a project. Installing the floor involves the same sorts of things you'd need to consider when creating a foundation— determining what sort of barrier you need, laying subfloor— plus creating the flooring mix and sealing it. And since you're less likely to be installing it in just one room than, say, the whole first floor, it's going to be a big job, but it's doable for those with some DIY chops and the interest in learning a cool new way to build. Check out a good tutorial from Natural Home Magazine to see what you're getting yourself in to.

More on rammed earth flooring
The Dirt on Rammed Earth
Green Glossary: Rammed Earth
Renovation Nation Episode: Dixon, NM: Rammed Earth Home
Rammed Earth Goes to the Chickens