Our House

First 10" of EPS-crete wall

I’ve got the EPS-crete wall started.  The forms come off today and they get moved up ready for the next layer.  So far, I’m liking both the process and the result.  It’s dead easy to mix, light to shovel, doesn’t require herculean forms and is easy to press into place.

The reinforcing wire isn’t necessary for EPS-crete used as post-and-beam infill, but the lower part of this wall will be backfilled for the first foot plus a bit, so the wire’s insurance.  When the foundation was poured I included old bolts, drill bits and big bent nails sticking up down the centerline to which the reinforcing wire has been fastened.  This is light duty construction.  The posts do all the “hold the building up” work.

Before I give you the mix recipe, here’s how I prepared the EPS for mixing.  You’ve already seen my foam shredder/grinder.  I transferred the ground EPS from the shredder box into tall kitchen garbage bags.  Into each bag I added between 2 and 3 pints of warm water to which I’ve added a squirt of dish soap.  The dish soap is a surfactant to break the surface tension on the EPS.  Mix the soap to water ratio as if you were planning to wash dishes with it.  Tie the top of the bag closed.  The bags I use have four “ears”.  I tie them diagonally in half-bows I can undo.  The goal is to keep the EPS and water/soap mix inside when I start rolling the bag around to distribute the soapy water.

The longer you can leave the mix in the bag (and even in the sun to help reduce the soapy water’s viscosity and allow it to spread) and the more times you can rotate it to get the liquid evenly distributed, the better the result.  Otherwise the water drains to the bottom without evenly coating the ground EPS.

The beauty of this method is, when it comes to the point where you’re mixing the EPS-crete, the ground foam is quite controllable.  It doesn’t float around, blow around or stick to anything via static electricity.  You can measure and mix it without getting it everywhere.  In other words, it ends up in the mix instead of all over you, the ground, the equipment, your other ingredients and your helpers.

Here’s the mix part.  Bear in mind this is subject to change based on how this wall  performs.

• 2 parts cement
• 2 parts sand
• 1 part water
• 1 part recycled latex paint
• 16 parts ground EPS  (This is the most flexible part.  More or less depending on what you’re doing.)

I made my first batch in a cement mixer but it’s more work any way you look at it.  See my note at the end regarding using the mixer.  Lucky for me, our cement mixer stopped working after the first batch.  <wince>  The cement mixer came to us used with a history of being poorly maintained.    In addition to a new cord, the intermediate drive shaft needs rebushed and the central pinion (shaft fastening the barrel to the frame) needs replaced.    I’ll fix it but it’s going to be a major job I don’t want to make time for right now.

After losing the use of the cement mixer, Wadly mixed the remainder of the batches by hand.  It’s really easy to do using a short handled shovel.

For measuring, I’m using a plaster straight-sided plastic pitcher.  The shape, material and fact that it came pre-equipped with an integrated handle means the plastic pitcher works awesomely well.  It would be nice to have one for each type of ingredient.  Hmm.  It might be worth hitting the dollar store to see what I can find.

Because this recipe is by parts, it’s an easy recipe to duplicate.

1. Give the bag of EPS a couple of flips to distribute any water that’s settled out.  Measure the ground EPS into the wheelbarrow, leveling it out.
2. Sprinkle the sand over the top.
3. Sprinkle the cement (be careful not to create dust and yes, you should be wearing a mask) over the top of that.
4. Mix the latex paint and water together.  I use an old paint can to mix this in.  Stir thoroughly.  I should use a 5 gallon bucket and premix a whole bunch at once.  Next time.
5. Drizzle the paint and water mix over the top.
6. Shovel mix until everything is completely combined.  Watch for and break up any paint balls.  I would like to have a drill mounted stirrer for combining the paint and water to help avoid this problem.
7. Shovel the mix into the form.  It’s fluffy so you’ll need to pack it in you will have voids in the project.  If one person shovels and one person packs, the work goes quickly.

I’ve combined ingredients in a different order but the steps above produce the best result.

This mix isn’t runny like regular cement.  It’s wet enough stay in place when you pack it into the form and not so wet as to have any of the parts separate out.  If you make it too wet, you’re doing two negatives things; you’re weakening the concrete and making it wet enough to allow the EPS to separate out.  You’re after a mix that’s wet enough to stick together when you pack it and dry enough to have zero slump.  If you try to pack it and it crumbles, it’s too dry.  If you pack it and moisture comes out ANYWHERE, it’s WAY too wet.  If your mix is too wet, reduce the amount of water you’re adding to the bags of eps.  If you reduce the amount you add when you’re mixing, you’ll get more paint balls.

From experience I’m going to say you will have to scrape the sides of the concrete mixer if that’s what you use to mix.  This stuff, because it’s so light, will stick to the sides and not mix thoroughly.  There’s not enough weight to the mix for it to scrape the sides of the mixer for you.  Be prepared to stop the mixer, scrape the sides and restart.  Success depends on thorough mixing.

Once the mix has set, spray it twice a day with water to help keep the cement hydrated so it will cure strong.

The piece of foam I shredded was 5″ thick by 4′ long by 10″ wide.  It took about 4 minutes, much of that time spent flipping the piece over as it was thicker than the available shredding surface of my roller.  The width was not an issue, it was perfect.  I’ll either have to split the foam into thinner pieces or suffer through flipping them over numerous times to get them shredded.

The piece above nearly filled the receptacle to the top.  Hopefully Wadly and I can use it up this afternoon.

Set up and tested 1 1/2" pvc to fill the gap where the edges of the nail laden pvc don't meet. Motor installed, top deflector installed, ready to go.

I’ve got the foam shredder prototype working. The roller center is a solid stainless conveyor roller from a fresh produce processing plant.  My brother was going to add short spikes to it for my shredder drum but he ran out of time about five spikes into the project.  The pulley is from a box of stuff we collected somewhere and the key to hold the pulley on came out of a drawer.  The motor goes on the cement mixer and the belt was hanging on the shop wall.  The gray is aged black pvc pipe left over from some other project. I’ve drilled a grid of holes 1/2″ apart and stuffed the holes with 3/4″ roofing nails that were a box that went from my dad’s estate to Dan and then to us.

I started with just the pvc filled with roofing nails.  I was going to add a central shaft and pour it full of concrete but Dan sent the roller with bearings attached.  It seemed smarter to split the pvc and slide it over the roller rather than try and come up with a shaft and bearings.  There’s a trick to holding all the nails in place as you work.  If you need to know, ask me.

I probably don’t need the pvc filler in the blank spot, but I’d rather do what I can to ensure consistency in the particle size.  When I tested it without the pvc and while rotating the wheel by hand I ended up with occasional bigger chunks when the foam was caught by the blank space.

The last picture is the shredder ready to go.  The base/box is one of a pair built to act as supports for Dan’s lathe.  The bungy cords hold the door on to keep the shredded foam in.  The deflector is a cut down plastic waste basket that had multiple splits at the top.  I used a box knife on it to reshape it for this task.  It’s held down by gravity.  If that doesn’t work, I’ll figure out how to stabilize it.

To dispense the foam I’m going to flop the box onto its left side, undo the bungies and shovel the shredded foam into the mixer or storage container.

So far I have exactly zero dollars and a couple hours in this project. I think that’s pretty good for the result.

I’ve got two big pieces of  foam ready to grind.  Once it cools a little off a little bit outside I’ll shred them.  I’ll measure the size of the pieces and time how long it takes to shred them.  If I can get some foam shredded today Wadly and I can mix up a batch of eps-crete tomorrow.

Result with concrete lath mounted over original wood chipper screen.

I finally got to rescreening the wood chipper to use it as an EPS grinder.  It looks like it will work okay.  The foam pieces have to be small enough to fit in the hopper, but once introduced to the blades, the foam gets ground fine enough to do the job.

We’ll load the chipper into the back of a stable vehicle so we have a drop for mounting a collection bag.  I will be making it out of sun shade cloth if I can’t find a collection bag locally that will work.

I think we’re getting closer to spring.  I’ve got daffs up and my elephant garlic is poking through the dirt.  I’ve got quite a bit of pre-spring gardening to get done as weather permits.

Dan (brother) is still working on a foam grinder for me.  He’s not working so it might catch his attention a little more often and I might actually have something to play with by late spring.  As soon as I can grind some foam I’ll get the eps-crete infill installed in the north wall of the sun porch.  Once that’s done I can pour the last bit of footer and get the east wall glass put in.  Once that’s done I can get my fish tank moved in and my aquaponic grow wall (lettuce, tomatoes, peppers, et al grown in hydroton) put in place and start growing for our table.  Right now the fish tank is outside half sunk into the ground.  I can’t grow anything attached to it until the weather warms fairly dramatically unless I install a heater in the tank.  I can’t do that until I get the new electric service in (coming up soon!).  Getting the tank into the enclosed sun porch will greatly lengthen the growing season without increasing the electric bill.

It’s been so warm I haven’t been able to talk Wadly into installing the sawdust stove.  I keep hearing “next winter” when I mention it.  I know better than to push.  He pays the electric bill and collects the sawdust we’ll burn once the burner’s installed, so it’s best for me to just go with the flow.  When he’s ready, we’ll get it installed.  I’ll start pushing him mid to late summer so it’s done when the cold weather hits.

Judy of the woods do-it-yourself desk chair.

I occasionally do mad spates of research.  This morning I was trying to find a comfortable and supportive desk chair solution.  I spend hours at a time sitting at my desk and finding a chair that supports me properly is proving to be difficult.   That’s not the reason for this post.

In looking at desk chair images, I ran across the lovely image to the left.  This sort of thing makes me smile.  It’s an excellent example of someone thinking outside the box!

Judy’s chair struck a chord.  My current desk chair is being held in a relatively comfortable position by a length of cord, a cargo strap and a length of mountain tape (1″ wide flat nylon tube).  I’m not perfectly comfortable, the chair is still tipped a bit too far back, but I am *more* comfortable than I was before the cord, cargo strap and length of mountain tape.

The moral of this tale is, when we can get beyond vanity to cost effective function, we truly have come to the point where we can be thrifty and self-sufficient.  Judy of the woods looks to be a sister of my heart.  Check out her blog.  There’s a lot of interesting stuff there.

The day before yesterday Wadly and I test fired the sawdust stove out in the yard.  It really does work exactly as acclaimed.  We used fairly damp cedar sawdust (it’s what we had).  I had a little trouble getting it lighted (learning curve) but it burned just fine once it was lit.

Wadly’s planning to burn the paint off so it’s safe to light indoors.

You might want to check this out.  A person commenting on a previous post turned me onto a forum thread about a sawdust stove being used in a wood shop.  Thanks Nancy.

In future I hope to have dry hardwood sawdust to burn.  Keeping us supplied is going to be Wadly’s job.  Right now we have two stove loads of cedar sawdust.  That will do to get us started, but it won’t last beyond a day or two.

Note to self; learn how to braze and find your your anvil.

Raw sheet metal parts.

I took my concept for the bottom workings of the sawdust stove to our local sheet metal shop and they did a brilliant job of turning my concept into solid objects.  All this perfection (not the vent adapter which I got at Goodwill for $5) cost $89.  That’s a heck of a deal, in my mind.  I just don’t have the tools to easily cut and bend metal.

Yesterday I cut the hole for the sleeve/drawer in the 55 gallon drum.  The hole looks great.  It’s a tiny bit smaller than the final, but I’ll leave it as is until I talk to Lorr.  I’m dealing with a barrel that has a fairly good arch in the bottom, so want to have flexibility for which way I jump when putting this all together.

The hole in the sleeve (piece standing on end) has had its edges bent upward to facilitate centering and supporting the burn chamber.

All these bits (not the vent adapter) are to be tack welded Saturday at Lorr’s.  I’ll try and get good pics of the assembly process.

I haven’t cut the exhaust hole yet.  I don’t want to do that until I talk to Lorr.  He may not be okay with using the vent adapter.  Cutting the hole to match the vent adapter reduces my ability to step back and punt.

Since the RMH workshop I’ve been tossing around ideas for my installation.  With rocket mass heaters, the devil really is in the details.  They’re super inexpensive to build if you can scrounge the parts and innovation is rampant and lauded IF it works.

The mock-up of my stove encourages me to find a larger diameter riser.  The 6″ well casing I have will work, but bigger in my case may be the difference between marginally functional and awesomely functional.  Ernie’s suggesting an 8″ core and I’m agreeing . . . bigger in this case is better as long as I don’t go above 8″.

I put a “want” out for 8″ well casing on our local freecycle and our County’s 2Good2Toss.  I’m not really expecting any results but I have to try.  I probably shouldn’t be fussing about this as the installation isn’t going to be a long term one.  I could use 8″ stove pipe.  It’s certainly more readily available, would easily last the couple years I need it to and I know where the scrap pile is for our local stove store.  But you know me, I’ve always got to say “what if”.

Logging is big in our area.  Short lengths of log truck reach (3/16″ thick 8″x6″ tubing) are pretty readily available.  With Wadly’s connections I could probably score 50+ inches of that fairly easily.  So the question is, can I use 8″x6″ steel tubing for the riser?  What effect will the rectangular shape have on the draw/draft?  I’ve posted queries on the RMH Experimenter’s Corner and and on the Permies Alternative Energy forum.  I won’t hold my breath waiting for answers.

Riser in place and base for barrel in the works Working through the exhaust port detail Mocked up exhaust port Making sure the barrel is properly supported With barrel added and fire started Nice clean burn, good draft Without an insulated riser, once the barrel warmed up, draft was lost and smoke-back was unfixable Knocked apart when the test was over

Last weekend I attended a rocket mass heater workshop put on by Ernie Wisner and Erica Ritter.  I learned SO much!  You cannot imagine!  I’m going to try and cover a very small portion of what I learned.

I learned I will not be able to use all the lovely free stainless steel ducting in the construction of my rocket mass heater.  Some I will re-purpose to improve air circulation between rooms.  Whatever I have left won’t go to waste.  You know me, I’ll find a use for it.

I spent the night at Ernie and Erica’s on the RMH bench in their living room.  My hips loved the heat.

My RMH requirements are a bit out of the norm, so I took my parts with me to do a bit of testing to see where I would have issues.  The whole process was extremely educational.  The pics on the left are thumbnails.  You’ll need to click the thumbnail to see the detail.

In addition to the four paying attendees was an awesome and ever changing group of young people known collectively as “the legs”.  You will see bits of them in the photos of my rocket mass heater test.

I’ll post more later.