R Scott

Impressive goal. I think you are on the right track, but I have no experience in that climate.

One thing I can comment on is ibc placement. If you sink them about a foot down they make a good base for a work or planter table.  Multipurpose space savings.

Eliot Coleman talks a LOT about winter harvesting. He does not do winter growing, he plants it to grow in the fall and coast through the low light of winter to be harvested fresh even though it doesn’t really grow in the lack of light

Your thatch breathes and insulates and does evaporative cooling  so it is really good in hot environments, be careful to not ruin that part of the roof. If you do a solid material, add plenty of ventilation at the peak.

I would second the latex concrete as probably easiest to source materials. It is heavy going on so be careful but it makes a pretty strong roof when cured.

Greg Martin wrote:There's commercially available closed cell glass foam.  It is a barrier, is insulative, is critter proof, is LONG lasting and is strong such that it can take a compressive load.

And WAY out of my price range for this project. I do want to experiment with some, I think it would be great for under the RMH bench

I had forgotten about pumice, THANK YOU for the reminder. That is probably my first choice for under slab insulation if it isn’t outrageous. It solves multiple issues at once.  On top of that will be a vapor barrier and soil cement or cob floor.

My current thought on the berm is to use aircrete with lime and copper sulfate. Both should be permanent non leaching omri approved deterrents for bugs and mold. I will be careful to keep it out of the topsoil and only under the umbrella.

Aaron Yarbrough wrote:
I don't know if you could find masonry screws with a gasket for attaching the metal panels to the backer board.

I don’t know but I do know you can get 3 inch long screws to go all the way through to the studs if you keep the foam board thinnish

I am leaning toward making aircrete with plenty of lime to kill/repel the bugs and rodents and waterproof it with 6 mil poly top and bottom.

As for the roof, I will use steel wool to plug the ribs in addition to the usual trim

That is great for rodents but I’m not sure it will work with termites. At least not for a long as I want it to.

My specific situation is for an Earthship inspired build. Walls on three sides that are bermed to the top with an insulation umbrella that is continuous from the roof down over the portion of the berm that is the thermal mass. Then more dirt on top to protect the membrane from UV and grow enough roots to hold the berm from washout.  My roof will be metal for rain collection so my water proofing is simpler than a full roof like a wofati, but the transition details are a bit tricky. I don’t want to leave a direct path from foam to wood under the 6mil or edpm but not create any thermal bridges either.

Mice are one thing, but the real insidious problem is termites. They LOVE chewing through foam board.  There are places that won’t insure houses with external insulation, including the required under the slab insulation, because you can’t inspect or repair the damage until it is catastrophic. Or they require a level of chemical prevention that borders on making a superfund site. No thanks.

I am either looking for an affordable non chemical way to waterproof aircrete from rising damp or to termite and rodent proof the whole umbrella.

Mail is actually a big problem some places. I don’t need a building permit for a small off grid cabin, BUT I needed a septic permit to get a mailing address and will need a building permit if I want grid power. Even if only for an ag building or barn with no house on the property. Ag buildings don’t need permit, permits are tailored for houses only. It is a backhanded way to require zoning when the state has exempted agriculture buildings including worker’s housing at the state level

Water really depends on what you have to work with. Do you have a truck or trailer? How hard is it to travel your road? How far to get the water? How often do you go that way anyways?  

My preferred budget method is a food grade IBC tote for home storage. It is by far the cheapest in gallons per dollar I can find. A second one to put in the back of the truck is convenient if you have to make a special trip for water. A transfer pump will move the water easy without buckets.

Can you drive a sand point well?  

I had to look up airlock doors to ensure you weren’t referencing space ship components (ha) and see that it’s another way- from what I understand- to refer to an entry way or vestibule. Am I picturing this right?  

Yup. Sorry I wasn’t clear.

Another reason I want curtains is because my wife can make them and I would have to make the shutters.

I don’t have either in my current house, but have friends with both.

Shutters are more efficient IF you actually use them, but are a complete pain if not designed correctly. They block outlets and you can’t put furniture close if not sized and hinged  properly. They also are all or nothing.

Drapes are much more flexible, but also a pain if you have pets, kids, or heat with wood.  Also are probably more expensive to make look good.

Go with whichever you are more comfortable working with or whichever you can source within your budget.

I am going to do both in my next house, depending on the location.  Mostly drapes because they will fit the design better with shutters and airlock doors where the drapes would be dangerous.