Learning how to build with Clay/Straw

Why clay/straw, you ask?   Good question.  Regular cob adobe type buildings like they have in the desert don't work in the subarctic.  1.  the clay walls conduct the cold (which is good in the desert, not so good in the cold) and 2. the freezing of the walls in the winter turns the cob mushy and it can't hold a roof or any structure.  So insulating with clay/straw in a timber frame structure is what works best for Alaska.  There are problems however.  Alaska's short summer means that anything thicker than a 12 inch wall can't get dry before winter.  If it's not dry, mold starts to appear and then rot.

So to make a house with clay/straw you have to start by making clay/straw bricks.  With a form, you can stuff the form with clay/straw and make an 8 inch brick.  The bricks are added to the clay/straw walls on each side.  So as soon as summer's over, or the next spring, the bricks are added and the wall becomes a very warm 28 inches thick.  That works---well, at least below the Alaska Range.

All homes in Alaska are made extremely air tight.  We have fancy air-exchangers to move the air out of the house and back in again to stay healthy.  With clay/straw, the walls breathe.  Moisture is wicked in and out of the house as the humidity inside and outside of the house fluctuates.  It's natural.  There's no off-gassing from the sheet rock, paint, or other man-made building materials.  And when you go into a clay/straw structure, you can just feel the difference.

These are only a few things we learned in the Clay/Straw Workshop taught by Lasse. All of us gathered Saturday morning in the bioshelter for an introduction to building with straw and clay.  We took notes, learned theory and learned about building with clay/straw bricks.   And then we went to work.                                            

The first task was to break up the clay.  We dug the clay out of the mountain in chunks and it needed to be turned into powder----an arduous task!

 Next, Lasse had us doing it the ancient way----mixing clay and water with a hoe in a bucket.  That, too, was arduous.  It's important to understand how much we take electricity for granted.  

Then Lasse got out the drill with a big paddle on the end and started mixing the clay with water in various thicknesses to teach us about different slips for different projects.  

Look at his fingers---they are just coated.
That's a cream consistency, so it's #2 slip---
just want we wanted for our clay/straw.

Look at how thick that is---like a milk-
shake.  That is a #3 slip

Next came the straw..... local straw from Palmer.

Out came the pitchforks and we went to town tossing the straw in the air while another person poured clay like dressing over a salad. We tossed and tossed and added more clay and tossed and tossed. 

More tossing!

Bridget tests the straw to see if it is
completely coated, but not too much.

Auri tests it too!

Finally the time came to start on the wall.  The lathe should have been 1x strips cut from any lumber using a table saw, but since I had no clue---I bought lathe.  Don't do that.  It's way too expensive.

First we had to "water proof" the bottom of the wall.  It would have been much easier to do this BEFORE we built the wall, but again---we didn't know.  So we snaked some EDPM rubberized membrane between the rocks in the trench and the 2x4s.  We needed to make sure that no water came up from the ground into the clay/straw walls.    

The trick is to get any water to go under the rubberized membrane, not on top of it.                                                                                                                                                                                                         We mixed perlite with #1.5 slip until it had the consistency of a rice crispy bar.  We tamped down the clay/perlite between the 2x4s.

OKAY!  We were finally ready for the clay/straw.  One of the other cool reasons to use clay/straw is that mice don't come in.  They don't like the clay.  The other reason is that you can take a lighter to clay/straw and it will not burn.  That is a huge advantage.   

Lasse explains what to do with the clay/straw and how to stuff it.

A very interested class

Avoid the voids---stuff the corners well,
but don't stuff the rest of it---
The more stuffed in it is,
the less it insulates.

Liz starts stuffing/placing

Notice how we put the lathe up the back side of the wall before we starting putting straw in.  The walls have to be ready before               clay/straw can go in.

These are the CHASES.  The rocket stove pipes
will come in and leave the greenhouse
through these holes.  

And now you can watch the wall go up.




Curt's checking the loftiness of it to make sure folks aren't getting carried away in their stuffing.

 The stuffers continued stuffing while the rest of us kept tossing straw or churning clay slip, or breaking up the clay chunks.  We had a great assembly line.

The sun came out that afternoon and we couldn't help but sit down and soak it in.  Most of us still sun-deprived from the dark winter.

Good Conversation.

Tea Time---reflecting on the process.

Poor Liz is tuckered out!

                             

And we finally called it a day!  Everyone was tired and sore and inspired.

What 10 people finished in a weekend.  A great start!  

The walls go up....

Solid timber walls, not 2x4s

We had hoped to place 12" diameter trees or timber in the ground from the mill at Indian.  That didn't happen, since the sawyer got the flu.  We were not planning to build two greenhouses, but that's what needed to happen now:  an inside and an outside wall.  We needed dry lumber fast and the only place we were sure of was Lowe's, since they store their wood indoors.  I tried Spenard, and several other small mills in the valley, but no one could get dry wood to us fast.



 So 2x4 walls 12" apart from Lowe's meant that we could stuff the clay/straw in the middle.

When it was snowing, we took that time to pre-build the walls in the garage, so this side went up fairly quickly.

As we were following the plans, we realized that we needed one more three foot drop.  But I was so sick of digging, I really wanted to quit.  So  we got out the tape measure to measure where the roof would end if we quit with what we had.  That was SUCH a wise thing to do.  It wasn't until then that we realized that I hadn't ordered enough roofing.  I had measured the roofing as if it were going to be flat, but in actuality it was a steep angle, the hypotenuse!  I loved Geometry in school, but it certainly didn't occur to me that I needed a longer piece of roofing because it was an angled roof.  So, my wish came true.  We couldn't go down one more level because there wasn't enough roof!  :-)

Notice that we had to dig trenches for good drainage and fill the trenches with rocks or urbanite. Urbanite is broken up pieces of concrete and is getting more and more popular as a recycled building material.

Luckily a guy in Anchorage took out an old sidewalk at his place and offered the pieces for free on Craig's list.  So I went and loaded them up and brought them home.  We had so many rocks that came up from the ground, I only needed the urbanite on a couple of trenches.

It was about at this point that we realized we might not make the deadline of June 1st.  I had 10 people signed up for the course.  I had Lasse committed to coming.  It was getting stressful.  Luckily Curt had some time off of work and could work with me all day.



I started racking my brains trying to remember who had kids in the neighborhood.  Luckily I found two boy scouts. They worked two days and I didn't even take their pictures!  We couldn't have finished without them!

From the garage roof.

Slowly but surely.

 You can tell I was really tired, because I didn't take any pictures between here and the roof.


But if you look carefully, you will see it's only tacked on.  It's not permanently attached.

Nick came to help with the roof on Thursday and Friday.  

Saturday morning the class started and the roof was up.

The digging begins

Cold, cloudy, not much like spring....we began the process of building the northernmost clay/straw greenhouse in the United States.  I happened to notice that Erica Weisner put out a call for anyone who wanted to be included in her new book on rocket stoves in greenhouses. I jumped.  She would give me her plans for a small fee.  I would follow them and then do research for her so that others could learn.  I was happy to help pave the way for rocket stoves and I was excited to be included in her book.  We started out with the best of intentions.

The first task was to find the corner posts of the new building.  Sounds easy, right?  We had the side of the garage which we presumed was straight.  All we needed to do was to find the other 3 walls.....on an uneven slope....in the cold....   I made a long tape measure with duct tape and twine, so that we could measure longer than our 50' tape measure could reach.

We started with 4 ft out and we knew eventually it would be 3 ft down.  So we placed a post every 4 ft from the garage on both sides.....  

starting at the top and moving down the mountain in what we assumed was a straight line.    We used a plumb bob to make sure each post was vertical.

 Then we tried to find the bottom corners and make sure they were square.  Some of you reading this might see the error in our ways.  We just had no idea about how to come up with square corners.  We did A LOT of math that day.  Listen up, kiddies, you really DO need to pay attention in Math Class.  We had additional troubles since the ground was still frozen where we wanted to pound our stakes in. 

 We tried and tried to get the corners square.  It wasn't working.  We decided that maybe the twine was stretching, so we abandoned the project until we bought a 100' tape at the store the next day.

We did the 3,4,5 triangle method, and still it didn't work.  Then we thought we'd try measuring the diagonals and found that we couldn't make that match either.  We were out of luck.  It was close, just not as close as we wanted it.  Then it snowed!!!  May 15th or so. We couldn't believe it!   That put us back a couple of days.  June 1st was looming and we had to have the roof up.  Too bad there was no way to get a little back hoe over to that spot.

As we continued the more we kept wondering how we would dig out the dirt during the winter?  It wasn't long before I realized we would need to dig the levels now---before we built the walls.   Curt started where we thought the steps were going to go.   It would be a huge amount of work to get ready before June 1.

So I hired my friend Nick.  He and I worked on it for 8 hours the first day.  Curt and I continued working on it.  We started at the top since that was unfrozen and worked our way down the mountain.  Sometimes Curt had to pick ax through the ice.

Finally we were ready for the posts.  I had ordered Alaska Timbers from Indian.  I wanted this to be an all Alaskan, all natural greenhouse.  Sadly the sawyer got the flu and couldn't get out of bed to deliver the wood.  Because time was of the essence, we had to scramble.  On Craig's list we found some old railroad ties.  We borrowed the neighbor's snowmachine trailer and went to get them.  Yes they leach into the ground some, but on the other hand, I support railroads and we need to do something with the old railroad ties rather than throw them in the landfill.  Why not reuse them?  

But then came the problem:  ICE!  Not just the stuff we could expose to the sun and let it melt.  It was more like permafrost.  We needed to call in the big guns!  :0)

11 holes with that thing!  It was crazy!

Curt and I held on to that auger for dear life so it didn't swing around when it hit a rock and kick you in the ribs.  That hurt!  We stopped every so often, got down on our knees and dug all the rocks out of the hole so we could do it again.  We kept it a week and got the outside holes dug.  I had wanted inside posts as well, to hold up the roof, but after we did the outside ones, I was willing to listen to another idea of Curts:  BCI beams.  Manufactured in Oregon, but.....no more drilling?  I went for it.  I was done with drilling.

It took a little bit of effort to get those humongous railroad ties in place too.

Thanks goodness for the dolly!

We brought it to the edge and
flipped it down onto the right
level.

We lined it up on the hole

We had to level it on its broken piece of cement

Curt lifted it in.

Once leveled we tamped in dirt all around it

 We were so happy to get rid of the auger and wanted to rest, but June 1st was coming fast.

The old garden cart needed a rest though.  Curt worked it hard!