Adobe?

Over the last few months we’ve occasionally had contractors to the house in Tucson as we look for someone to help us with our upcoming remodel. Once or twice I thought I might have heard a contractor referring to our house as “adobe.” It struck me as slightly odd, but I didn’t think too much about it. People who are new to the southwest will occasionally refer to anything with a stucco exterior as “adobe”, but we don’t even have a stucco exterior. And this was a knowledgable contractor calling our house adobe? Did I hear him right?

Recently we were looking at the brick wall in our kitchen/dining area. We believe it was once an exterior wall before the house was expanded. When examining it, John realized it was a solid, 8″ thick brick wall. We had assumed it was an exterior layer of brick with wood framing behind it. But that’s not the case. The brick is the wall – the wall is simply one layer of very thick brick.

The vast majority of US homes are stick (wood) framed, and then stucco or brick or other kinds of siding are used for the exterior finishing. On the inside is drywall (taped, spackled and painted). Layers: drywall, stick frame, siding. So in a typical house, when you hang a picture you’re nailing into drywall, unless you hunt around and find a stud – one of the two-by-fours or two-by-sixes used as framing inside the walls.

An adobe house doesn’t have wood framing inside. Adobe walls are solid adobe and thick, often 8″ thick. Turns out our exterior walls – and our interior walls that used to be exterior walls – are built from a single layer of 8″ thick slabs of brick. That’s it. Just brick. Just solid walls – no layers. That sounds like adobe construction – having no wood framing on the inside.

But wait. Are our bricks adobe? What are these soft bricks anyway? They are enormous; 8 inches wide and 16 inches long.

I got onto the internet to figure it out. What are our large, relatively soft bricks called? Adobe means mud in Spanish. Are they mud bricks? No. Mud bricks aren’t fired, they’re just dried. These bricks are definitely fired, they’re just not as hard as the smaller bricks found in the majority of the US.

Or are they slump block, like a friend of mine once called them? No…our brick is softer, lighter in weight and larger than slump block. But I discovered why she guessed that. The internet says, “Slump Block is a concrete block unit that is removed from the mold before it has a chance to completely set. This causes the concrete block to keep a slumped appearance like adobe brick…” Like adobe brick? Could that be what we have? And, “…slump block is a concrete block made to look like adobe or burnt adobe…”

Burnt adobe! That’s it! That’s the word I was looking for. “Burnt”, meaning that the adobe bricks were fired. Now that I knew the name for what we have, I was able to find out lot more information.

Guess what? According to the internet, “Tucson, in Pima County Arizona, has about 15% of all the burnt adobe homes built in the US from the 1960s through the 80s.
Basically, burnt adobe homes are bricks made out of mud that are much thicker and larger than typical bricks. The concept behind building with adobe is that adobe walls have enough thermal mass to absorb heat during the day and release it at night thus keeping the home at a fairly stable temperature year round.”

Elsewhere it says, “Older adobe homes are typically reddish in color while the ones made in the 80s are more of a yellow/tan-ish color. Some people confuse slump block and/or red brick homes for adobe but neither material is nearly as thick as adobe.”

Yep, apparently burnt-adobe brick homes are real adobe homes. In fact, I learned that adobe homes are made with adobe bricks, not heaps of mud like I had ignorantly imagined, lol. That explains the exposed mud-brick interiors common in New Mexico. I just thought I was looking at a decorative element on the interior. I didn’t realize it’s the same one wall! Duh!

The adobe homes in New Mexico are made with adobe brick like mine – but then a surface layer of adobe mud is added on top of the adobe brick, hiding the bricks. These adobe homes in Tucson just don’t have the outer layer of adobe coating. Instead, the adobe bricks are left exposed.

Another website, based in California which specializes in repairing a different type of brick says, “If your home was built with “Burnt Adobe” an orange-pinkish brick common in Tucson, AZ, Sonora, and Baja Mexico, your best resources for repairs would be in the Tucson area.”

Yep, that’s us! Definitely pinkish-orange and common in Tucson. These are apparently 100% clay mud, with no concrete.

Not only is my house a genuine adobe home, the type of adobe is specific to Tucson and the Sonora region. I love regional character and am very pleased to have a house that is distinctly Tucsonian.

Well, there you go. I never thought I’d have a real adobe house. I can’t believe I didn’t realize I was buying an adobe house! I thought it was a brick exterior over stick frame construction, just like a million other houses in the US. It took me a year and a half to figure it out! But sure enough, I see now, it’s right there in the real estate listing, “Construction materials: Burnt Adobe”

So if our walls are solid adobe brick, how are the electric lines run? With a typical wood frame construction, they’re run in the hollow spaces between the two-by-four wooden planks. Luckily most of our interior walls are wood frame construction with drywall, which makes it easier. It’s just the exterior walls (and the interior walls that were once exterior walls) that are completely solid brick. But we do have some electrical outlets on our brick walls. How? It turns out these bricks are soft enough that you can dig little tunnels through them for electric lines! But it’s not easy. Also you can hide them under wood trim.

And where does the insulation go? Haha, there isn’t any. And there’s no way to add it, because there’s no hollow space to put it. We can’t even blow it in. The walls are solid. That interior brick is the exterior brick. No layers.

Now that I know we have 8″ thick, burnt adobe walls rather than stick frame construction with drywall, I’m realizing that we could remove the interior plaster that’s in most of the rooms and expose more brick if we wanted to. But even an accent wall or two sounds like it would be a ton of work. Youtube shows how to remove plaster from regular brick, but our burnt-adobe bricks are softer than standard brick and I’m not sure we could get the plaster off without damaging them.

It also occurs to me that we could do the faux Italian-villa look, removing patches of plaster to reveal the brick in random places, as if the plaster was slowly denigrating with age. LOL! We could create a faux historic Italy interior with our adobe brick in the living room, on two walls of the master bedroom, two walls of the office, one wall of the guest bedroom, one wall of all three bathrooms…OMG we could do faux Italian villa everywhere! The interior side of all of our exterior walls is plaster on brick. But don’t worry, we’re not going to do that. Creating a crumbling-plaster look always seemed so fake to me.

Oh – even worse – they make wallpaper to mimic the look!! OMG, LOL, this is wallpaper for sale:

We could do that, but for reals! Uh no thanks.

Meanwhile we have more immediate issues to worry about. I noticed during my research phrases like, “if cared for properly”, and, “if well-maintained” and “except for the maintenance involved”…uh-oh.

Yep. Apparently we’re supposed to be resealing the brick regularly because otherwise it absorbs water. We’re not supposed to plant anything up against it. And we’re not supposed to irrigate anywhere near it. Because it can sop up the water and develop black mold! Once I’d heard of it, I realized I’ve seen the black mold on houses in my neighborhood.