Cabinet Nailers

In conventional construction, there are plenty of ways to attach cabinetry and other necessary fixtures to walls. Those ways are called two-by-fours which are used to build the frame of the house. In our straw bale house, there are no two-by-fours. So how do you connect cabinets to walls when the only material available is straw covered with plaster? The answer is “nailers.”

Before plastering the kitchen wall, Scott inserted nailers along the south wall at the height required by our cabinet maker.

Scott began by using the chain saw to cut notches in the bale wall at the specified height.

He then made large (8-inch by 5-inch) triangular spikes out of plywood and screwed short lengths of two-by-fours to each spike. This is the “nailer" which Scott forced into its chain saw notch.

In order to secure each nailer in place, Scott screwed it into the nearest bamboo pole.

Before plastering over the nailers, we made a photo record of their location and height. We now have a very sturdy support system for our soon-to-be-completed (fingers crossed) cabinets.

Design Feature Number Two

When deciding how to design the kitchen counters and entryway, we realized the entryway window had been positioned two feet too far to the west. Because the cement floor for the kitchen had already been poured two years earlier, it was impossible to move the kitchen cabinets because the cement would show. This misplacement also meant the counter back would impinge on the window. Our question was how could we turn this porblem into a "Oh, that's a cool design" instead of an "Oops! that sure was a mistake."

As we looked for a material to use as a facade for the side of the cabinets that would show in the living room and entryway, we found the answer to our problem.

Here you can see that the cement kitchen floor (eventually to be covered with cork) lines up directly with the frame of the window. The kitchen cabinets line up with the cement floor and, thus, the window. If the window were two feet to the right, the cabinets would have met with the wall with plenty of space to spare for the window.

We built a pony wall to contain the kitchen peninsula wiring and to frame the back side of the counter.

Eventually we will cover and trim the entryway side of this wall and living room side of the kitchen counter with corregated roofing metal that has an aged metallic finish. This metal is actually painted instead of rusted and can be purchased from paintedrustedroofing.com. Antique porcelain doorknobs will serve as coat hangers.

Our hope is that these things, along with a cushion on the stone windowseat will make this a comfortable place to welcome visitors.

Lime and Lime Again

I asked Scott why we decided to use lime plaster on the walls inside of the south bumpout since we were using earthen plaster everywhere else in the house. He said, “Because we want to practice for the exterior lime plaster and because we want to put it in the most conspicuous place possible. Ha. Ha. Ha.”

Doug said this would give us the proper motivation to do it well.

And, as I wrote this post, Scott said, “We did it VERY well.”

Yes, there was a spot of plaster failure (easily corrected), but we were successful in practicing the lime plaster application technique as well as beginning to learn how to apply lime wash to color it.

First we mixed up a load of lime plaster. It consists of Type S lime, pumice, sand, soda ash, kaolin clay, water and poly fibers.

You can see the poly fibers. They are meant to hold the plaster together. In earthen plaster, straw plays this role.

West side of the south bumpout: we planned to plaster the lath and straw portion on the right side of this wall and the OSB (oriented strand board) above the door and below the right-hand window. Because the surface is so smooth, plaster won't stick to OSB easily. To help with this challenge, we stapled expanded metal lath to the OSB.

First Scott sprays water on the surfaces to be plastered. The tape and plastic are meant to keep the lime plaster off of the wood. Otherwise, the lime will change the color of the wood.

Scott begins the first coat of plaster on the wall.

Scott begins the second coat of plaster on the wall.

Scott finishes the second coat of plaster. The texture in the first coat is the scratch pattern that we added to the first layer. This provides the tooth (something for the plaster to grab on to) for the second layer.

The finished lime plaster looks just like sidewalk cement.

Now we will add color to the wall with a lime wash. I begin by measuring a given quantity of Type S Lime. (Note the dust mask and rubber gloves. Lime is not a benign material.)

After several experiments on our practice board, we chose yellow ochre.

It doesn't take much pigment to make a lot of color.

We mixed the wash to the consistency of skim milk. This was very important. On our practice wall, even though the directions clearly stated "consistency of skim milk," it didn't seem like "paint." We made the wash thicker. When it dried, there were hundreds of little cracks and it flaked off. This is called "crazing." When we followed the directions, it worked perfectly. Imagine that!

Before applying the wash, Scott used a sponge to remove loose sand grains from the surface.

Lime wash is semi-transparent when applied.

The wash becomes opaque as it dries. You can see the beginning of this in the upper left-hand corner of the picture.

We decided the color needed to be more robust so we add six more coats of wash. The lower right-hand corner took the longest time to dry. We still don't know why.

After six coats, the color was beautiful but it seemed a little too uniform and flat. We hoped to give the wall a little depth by sponging on one more layer of yellow ochre containing a little more pigment.

We didn't like the result.

So Scott added two more thin coats, one applied horizontally and the applied vertically. Now we love it! The only thing we need to do to complete the walls in the south bumpout is put on the last bit of window trim.

It A Matter of Lime

Water and straw do not go well together...at least not when that water is precipitation and the straw is your wall. Therefore, it is extremely important to design a straw bale house with features that keep rain and snow away from the straw walls.

Our house, with its eight-foot porch, demonstrates one way to do this. However, on two sections of the house, the north kitchen bumpout and the south sunroom bumpout, there is no porch. There is only an eighteen-inch eave overhang. This is perfect for passive solar design but not so good for shedding weather.

In order to protect these two vulnerable walls, we will use lime plaster rather than the earthen plaster used under the porch. Earthen plaster will erode when precipitation hits it. In contrast, lime plaster chemically sets up in such a way that the plaster becomes hard enough to shed water without eroding.

We actually have two such scenarios to deal with. On the south sunroom bumpout, where we have three, nine-foot by five-foot windows, we decided against using any straw at all. You might ask why. Of course, straw bales have excellent insulative value, but, as mentioned above, you must protect the bales from moisture. There is only room for one bale of straw beneath these huge windows. To us, it seemed that one bale would provide minimal insulation and, as an extra bonus, would present all of the challenges of moisture exposure. So, no bales there.

Instead, we framed this section with 2X6s and our timber frame. We covered the exterior and interior with oriented strand board (OSB) then insulated the air space between the OSB walls and the ceiling with icynene foam (see June 23, 2011 - More Insulation post). We stapled expanded metal lath to the OSB to provide a tooth for the plaster. Now we have great insulation, no moisture issues and an opportunity to use lime plaster on the inside and the outside of the south sunroom bumpout.

Scott made our exterior plaster with Type S lime purchased in bags from our local building supplier, Loa Builders. He added water, sand, polypropylene fibers, pumice (purchased  from Hess Pumice in Malad, Idaho), kaolin clay and soda ash.

There are two main challenges to using lime. One, it is extremely caustic so we needed to wear  rubber gloves, dust masks and eye protection. Two, lime plaster does not like wind or direct sun, so we needed to wait for a calm day. When two such days were in the forecast we set to work. The 18-inch eave overhang was enough to shadow the wall for nearly the entire day, so the wall was shaded as we worked. Once we finished the first lime plaster coat, we protected the lime from sun and wind by leaning boards against the lower part of the wall. The upper part was shaded by the eaves. For the next two days, Scott misted the lime periodically to prevent it from drying out too quickly. The result was perfect...no cracks and the first of two lime coats finished!

Scott applying plaster under the eaves

A section of wall with the first lime coat

Pete helping

The entire wall with the first lime coat finished

Adobe Wall

As I write this post, I am reminded that our initial building plan was to complete this house in just three years. I am also reminded of the construction adage: building will always take more money and more time than you think. This is indeed true for yet another pair of home builders - us.

Scott and I have been back in Torrey for one week now. However Scott completed a big project here while I was wrapping up loose ends in Logan. He built the adobe wall behind our masonry stove. Our thinking is that our masonry stove will heat our big main room and, at the same time, heat the adobe wall. The warm wall will then heat the air in Scott's office on the other side.

So, in early May, Scott contemplated this stack of 151 adobe bricks, which we made last summer with the help of my brother John's family: Wesley, Casey, Kelli, Jessica, Barbara and John.



 

First Scott framed an 8-foot X 8-foot wall.

He then set up a story pole on the edges of the studs. The purpose of a story pole (also called preacher board or jury stick) is to keep the wall level and plumb as well as to keep the courses at the correct height. He stretched a string aligned with the marks on the story pole and stacked the wall.

One concern we hoped to address was the stability of such a narrow, tall wall - 5 1/2 inches wide by 8 feet tall. To tie the entire wall together, Scott placed a masonry ladder (a welded-metal lattice) within the mortar every other course. The ends of the ladder were attached to the frame on each side of the wall.

The mortar recipe was essentially the same mix used in the plaster on the exterior of the house - high-clay-content dirt from our property, a little added masonry sand, finely chopped straw and water. 

One month later, the mortar has dried and the wall seems perfect. The only thing we have left to do is plaster both sides. That should happen this summer.

A Mouse in the House

When discussing straw bale construction with folks who are new to the concept, we hear some pretty predictable questions.

One of the first things people want to know about is fire danger. While loose straw will burn, baled straw less easily supports flame. That’s because the straw in bales is densely packed. This inhibits oxygen flow needed for fuel combustion. And baled straw covered on all sides with thick plaster is nearly fireproof.

What about bugs? Straw is not like hay, so there is not much nutritional value in it. And once the bales are plastered, there is no avenue for bugs to enter the walls.

Mice? Well, there is grain left in the straw when it is harvested and baled. This does attract mice, especially when they discover what a warm, comfy place it is. That is why it is important to get a coat of plaster on the walls as soon as possible. We were able to get plaster on the exterior of the house last year, but the interior had to wait until this summer. When we visited Torrey last winter, we worried that we would find a lot of mouse damage but we were lucky. This was really the only spot we found evidence of uninvited guests.

We set some traps to capture the little critters, caught a dozen and didn't have any in the house after that. Now our cats are with us. One of them has slain at least 20 mice in the yard around the house.
 He's not called Peter Panther for nothing!

Sometimes, with a little chuckle, people make reference to “the big bad wolf.” Keep in mind that wolves are on the endangered species list, so there are not many of them around anymore. And we’ve yet to hear of huffing and puffing as a cause for the collapse of a straw bale house.

Built-ins

While we have been researching cabinets and shelving, we’ve often come across the term “built-ins.” They probably aren’t referring to built-in table saws though.

Last summer, before we put even the first bale of straw in place, we set our very heavy, cast-iron table saw inside the house with the help of our tractor. This saved us time when we needed to cut the many, many, many pieces of wood required to make window bucks, door trim, lath and more. All summer long that table saw sat in Scott’s office doing the work it was created to do. As the days passed by, bales were stacked, plaster was applied, and doors and window installed—the house rose up around it.

Now we are ready to plaster the inside of the house, but we had to get the table saw out. The size of the saw was slightly smaller than the width of the door (we actually did measure to make sure this was true before finishing the walls). But once the walls were up and the doors on, the saw seemed huge. One part of the saw did need to be removed and then a 32-inch-wide, 400 pound mass had to be ever so carefully eased through a 36 inch door without bashing the wood trim. Scott moved it himself, working very slowly and carefully using basic tools—inclined planes and levers—and got it out the door and down to the porch where the tractor could pick it up and move it to the garage. The door trim still looks good.

Table Saw in situ

Table Saw "out situ"