Aaron Yarbrough

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since Jan 31, 2013
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Biography
My wife and I live in an off grid cabin on our half acre homestead in Central Texas. I have lots of interests but some of them in the Permies vein are natural building, building science, sustainable design, waste management, food forests and raising quail. I document many of my projects on
offgridburbia.com
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Recent posts by Aaron Yarbrough

Brie Lynn wrote:Hey, how are things going with all this? It looks like this workshop idea never took off. Any plans to pick it back up?



I did a couple that weren't well attended. I'll probably do light clay straw and earthen plaster work parties in the winter/spring. I might also do something with lower cost materials like soap making to see if I can generate more of a following before trying more of the spendy projects.  
1 week ago
Welcome to Permies! I always steer people just getting started towards Gaia's Garden by Toby Hemenway. It's an intro to permaculture focused on people with suburban lots.

Andy Ze wrote:We're having a pretty good year. Lots of okra and figs. Highly recommend those to anybody else in Central TX who has clay-ish soil.

Here's a look at our compost bucket. I don't think it's big enough for worms. What's going on with all these grubs?



They look like black soldier fly larva. I agree with the figs and the okra.
2 weeks ago
Hey David,

Welcome to Permies! Sounds like an adventure. I hope you find some people to take you up on the offer. You might want to post some pictures or make a little intro video. I find that's helpful for getting people's attention.
2 weeks ago
Hello! Welcome to Permies!
3 weeks ago

Raymond Liljeros wrote:
Today I live in a concrete house with hugh windows and bays east west,
the opposite of what you and everyone recommends
However the west wall is shaded by big oak trees and the eat has a veranda so
the sun does not hit the inner walls.



Yes, siting can make a big difference. We have a 100+ year old oak tree on the west side of our house that provides really good shade in the afternoon.


Raymond Liljeros wrote:
The funny thing is that when I read about all these very ecological houses on the net,
during a heat swell, they talk about 79°F.
This is what I have in my home today with 100°F outside this week.
So it seems to me that we cannot do much naturally to improve the temperatures
when the night stays around 70-74°F.



Earth sheltering is the only option I know of that can keep a house naturally cool in warmer climates. Generating air flow has limited effectiveness when outside air is hot and humid.


Raymond Liljeros wrote:
From what I understand, the real heavy beautiful cob is only good for areas
where the night temperatures drop substantially. I also did a rammed earth
workshop but althogh quite easy technically, it is heavy work.


In warm climates cob is really useful inside your building envelope. I agree, it is heavy work, that's why I generally tend toward light clay straw/slip straw

Raymond Liljeros wrote:
I wonder if I should make my futur houses walls of slipclay and woodchips
20 inches thick to give it the best ? or would that not really do anything agains
the summer heat ?


I heard it recommended that light clay straw walls not be thicker than 12 inches because it will begin to rot before fully curing. A 20 inch thick clay and woodchip wall would essentially be cob which if well shaded would work tolerably well. I know some professional natural builders who built a cob house near me with 24 inch thick walls and on hot days interior temperatures will still rise into the mid to high 70s. Most heat gain comes via your roof so I would really focus on that.

Raymond Liljeros wrote:
So you are right from what I also read about your recommendations for est/west,
openings to the south for the winter however, I am not so keen on large overhead
protections because you loose the light into the house during the in between seasons.
I would rather come up with some temporary shading structures for the only 3 months
of the summer here, mid-june to mid-september, and then let all the sun into the house.
The large overhead protections will interfere with sun striking into the house in late
april-may and late september-october.  



Here is a discussion we had on Permies about passive solar design I think you'll find useful
https://permies.com/t/174169/Passive-Solar-Design-Roof-Overhang


Raymond Liljeros wrote:
Another idea I have is to install for best light inside the house during the off season,
big west and east windows and also big roof windows, VELUX and construct during
the hot season some custom made "double insulation"
to put on top of these windows and roof VELUX because the standard outside VELUX
shade is not efficient enough and also very expensive.



I think skylights are problematic because they are difficult to weather seal and like you said expensive. East and West facing windows with awnings would work. In our cabin we have long skinny windows mounted just below ceiling height along the whole north and south sides of the house that bring in a fair amount of light.


Raymond Liljeros wrote:
And you are right, the only natural cooling possibility that we have is the
underground but the land is flat where I will build so I think that this is not an option,
otherwise it must be a great option to put parts of the house underground.  
The canadien or provencial well would be another possibility
but it is rather complicated to maintain, and I wonder about humidity coming up
into the house from such a well as this installation gets older,


It's better for drainage and other logistics if you build the house above ground and build up a berm around it. That's how we built our partially earth sheltered cottage.


Raymond Liljeros wrote:
Thank you so much for your input, this is a great forum.


You're welcome. I agree.
4 weeks ago
I've heard Germany is very big into using mass timber to build large commercial building which is an engineered wood product made from wood particles like chips or sawdust or strands. It's neat because the timbers are extremely stable and can be made very precisely but require lots of processing and binders. There is also no increased insulation value over natural wood.  
4 weeks ago
Hey Raymond,

Welcome to Permies!

In climates without big daily temperature swings I like to use materials with higher insulation values like light clay straw/slip straw or straw bale.

I think the big key is to orient your house so the majority of your windows are on the sunward side (south in the northern hemisphere) with smaller windows,  located higher on the wall on the north side of the house and no or well shaded windows on the east and west sides.

Next, shade your walls and windows with a substantial roof overhangs. In a warm climate in the northern hemisphere I don't won't the sun coming through the windows on the south side of my house until November. In your climate September or October might be better. On the subjects of roofs, venting the roof deck or building a double roof is also a really good passive cooling strategy.

Put a lot of thermal mass inside the house in the form of earthen floors and trombe or cob interior walls. It the winter with sun streaming in the windows the mass will absorb heat and in the summer it will hold on to the cool under the shade of the roof.

Earth sheltered is also a really good option with some caveats that we could discuss if you're interested.

In any case I would make a contingency plan for installing an air conditioning system. With a mini split system that involves planning for a place to put indoor evaporator unit and outdoor compressor unit and running wiring for the unit. If you'd don't need it. Fantastic! If you do it won't require any major remodeling.
4 weeks ago
Hey Raymond,

Sawdust and wood chips won't provide the tensile strength nor the insulation value of straw.

With any earthen construction method clay is the glue but the interwoven strands of straw(or any fiber) is the primary ingredient preventing it from falling apart. The hollow straw stalks trap air in the wall which provides insulation.



4 weeks ago

Vickie Moore wrote:I’ve had a 5 gallon bucket that had fish remains in water to make a slurry to put on my plants. I forgot about being there, I got sick. It has been sealed for two years. I’m afraid to open the bucket. What will I find when I open it?



That sounds terrifying. Good luck!
4 weeks ago