While munching on pizza the other night, conversation drifted to the topic of adobe homes. Living in our hot, dry Texas climate lends itself to homes built from mud. We went over the pros: the bricks can be made on-site with little training, they're "cheap as dirt," they offer natural insulation, and the nature of the building material allows much room for creativity. And that's just what we could think of on the spot.
But when asked for a downside, we were hard-pressed to come up with an immediate answer. So we did some digging.
Late last year, we had a question from a reader here at Re-Nest who lives in an adobe home and has problems with insulation. The reader said her house, "contrary to popular belief, it is not particularly energy efficient."
Well, that definitely seemed contrary to what we'd always heard about adobe homes.
But other than that (something that can be remedied), we found that other cons could include the fact that adobe construction needs dry, temperate weather (wet or freezing conditions are not conducive to putting up a mud-brick house) and that sometimes critters can burrow through the bricks and weaken walls (something that can be prevented or lessened by using plaster).
So to us, it still sounds like the benefits of building an adobe home still far outweigh the downsides. What do you think? Should we build more and more adobe houses in climates where they're appropriate? (We think so!)
For more, turn to The Natural House by Daniel Chiras.
Photo by drouu via sxc.hu.
According to the Encyclopedia of Energy Engineering and Technology By Barney L. Capehart (Thank you, Google Book Search) a thick (10-30 inches) adobe wall has a thermal resistance from R2 to R10. The Department of Energy recommends adding insulationg with an R value of 7.8 on a concrete masonry wall (closest thing to adobe I could get) in Austin, Texas, so I would say adobe wouldn't really cut it for "natural insulation."
On the other hand, adobe has a large thermal load so it would take a while to change temperatures, resulting in the bricks slowly heating up over the course of the day and then re-radiating the heat back during the night. Of course, this only helps you if it gets cool again at night. You'd be in trouble if it didn't.
Some downsides I could come up with just off the top of my head: it would be a pain to wire and plumb the home unless you did some kind of interior walls. Hanging things on walls would also suck with the same exception. A pipe leak could cause more structural damage in adobe than in a standard wood frame home. Because of the thick walls required (plus any interior framing you decided to do), the home would need a bigger footprint than a standard wood framed home in order to have the same amount of usable square footage.
I'd say a careful analysis of pros and cons would be in order before deciding to build an adobe home. Besides, the greenest thing is to live in high density housing, isn't it? And you definitely can't build high density with adobe, it just doesn't have the right structural properties.
view Tiamat_the_Red's profile
Interesting fact: In Santa Fe, you are *required* to build adobe structures, and you only have a certain number of colour choices for the exterior.
view anaximander's profile
How about the lack of flex in adobe structure? Here in CA, all of our historic Spanish Missions have been substantially "restored" (read; rebuilt) after they collapsed in our many earthquakes.
view wrenx's profile
Adobe is/was a product of its environment. That doesn't mean it's a good thing. But the biggest problem with adobe is that the true adobe craftsmen are dying off, and there are not enough people willing to starve to death while learning the trade.
view SunnyBlue's profile
First for hanging items on a wall you place what is often called a "deadman" in the wall. These are blocks of wood placed where you would want to have something to drill into. They are placed in slightly from the inner plaster. Secondly, you might want to explore something called "cob" which has passed some amazing shake table tests. These are what engineers and code types use to determine whether or not a building material or design would "hold up" in an earthquake.
As for wiring and plumbing you can run conduit through walls during building as empty conduit and pull wire later, or you can design a groove/shelf/whatever into the wall (assuming you are building cob) during building and use that run as your place of wire and cover it with a shelf, decorative board for hanging pictures, a chair rail (no, they've never been used to hide wiring ;)
Lastly, you need to understand some physics. There is a difference between thermal resistance and thermal mass. Thermal resistance means that the material or insulation will slow the temperature being transmitted across a differential gradient. Or... in simple terms it keeps the cold out and the warm in or the other way around if you live in a different climate. Thermal mass means that there is a time lag in that temperature change. This is why cities, which have huge thermal mass, are quite warm at night after the sun has gone down as the thermal mass, here concrete, is re-radiating the heat of the day.
This thermal mass traditionally made adobe homes extraordinarily comfortable in a hot, dry, clime. Read... before airconditioning.
All in all the low embodied energy of these methods of building that are suited to the comfort of their occupants in hot, dry climes means they are the type of building we need to see more of, especially as we don't need to use that chinese drywall in adobe or cob buildings!
view chokecherry's profile