Questions about using Earthbags for an earthship type build.

If you get your drainage correct, use vapor barriers, and cover it in concrete, is this type of construction possible and moisture-resistant?  My climate is humid sub-tropical, and I am aware that humidity will need active controlling during the humid months, but I don't want to go down this rabbit hole if the result is damp and moldy.   I am nowhere near ready to begin designing as I want to get clarification if the fickle weather in SE Kentucky would allow for such a structure.

The main draw of EB construction is the lower cost for many of the materials used.  I specifically mention using concrete because of our climate.  I know it is not a favorite of many on the site, but for us it would be a better suited wall covering material (provided it was done correctly of course).

I love many of the self-sustaining integrations of an Earthship, but the tire construction is a sticking point.  Physically for my family, it can't be done in a reasonable amount of time. If we were 20 years younger, it might have been possible, but as it is, we are in our late 40s  early 50s, and that amount of physical labor just to get the back wall of a house up would result in a tire wall that would go nowhere for a long time.  

Specifically, I am interested in these aspects:
* Thermal Mass/Bearmed back
* Rainwater catchment (We receive on average 50 inches per year where we are which would provide us with plenty of free water)
* Greywater system (Given our rainfall would it be better to avoid this one aspect?)
* Indoor greenhouse for both edible and non-edible plants.
* The incorporation of recycled materials where applicable

Having said all of this, if the concrete-coated EB would not work, would cinderblocks be the next best thing?  We are getting ready to inquire about an adjacent parcel of land that connects to ours, providing a beautiful spot for such a home.  My husband also has experience with partially underground home construction as he helped his sister and her husband build one, and he is aware of many of the issues that come along with them, but like me, he loves the idea and the energy savings that can be realized if done properly.

Hi Patience,

If you are considering concrete then I would just go with concrete blocks:
-you don't have to make your building material (a lot of time saved that can be used for other tasks)
-they are widely available
-they will make a normal looking house
-all accompanying materials and techniques are easily available and tested
-and last but not least - your husband's experience

Concrete blocks can be beautifully and easily plastered with pure lime plaster. Any architectural features can be easily incorporated. Installation of doors, windows, hanging objects is easy.
I would recommend getting any special info regarding masonry house construction from European sites - it's a standard there to built from masonry in various climates.

Cristobal Cristo wrote:Hi Patience,

If you are considering concrete then I would just go with concrete blocks:
-you don't have to make your building material (a lot of time saved that can be used for other tasks)
-they are widely available
-they will make a normal looking house
-all accompanying materials and techniques are easily available and tested
-and last but not least - your husband's experience

Concrete blocks can be beautifully and easily plastered with pure lime plaster. Any architectural features can be easily incorporated. Installation of doors, windows, hanging objects is easy.
I would recommend getting any special info regarding masonry house construction from European sites - it's a standard there to built from masonry in various climates.

Thank you Cristobal.  You have helped more than you realize.  :)

These non-biodegradable materials won’t be a food source for mold so that’s good.

One issue with thermal-mass is if it’s cold for a few days and then suddenly the air gets warm and humid. This can make an unheated space feel colder or cooler since a thermal mass will soak up heat if there’s no insulation on the inner wall and if there’s no furnace/stove heat source inside.  Worst case humidity could condense on an uninsulated thermal mass. It could feel a bit dank or musty at times, but mold-wise I’d guess probably wouldn’t be a health issue for the average person.

For a passive (energy saving) system, condensation on the thermal mass could in theory dehumidify the air and make it more comfortable.
On a water-repellent surface maybe the condensation could be drained away, however, I’d guess on a water absorbent surface having that liquid water in the structure would be unwanted.

If electricity is available, I wonder, maybe there’s a way to run an air conditioner to avoid condensation (by keeping the dew point below the thermal mass’ temperature).  To save energy maybe the heat from the back of the air conditioner could be pumped either outside or into the thermal mass whichever was cooler.

Mike Philips wrote:These non-biodegradable materials won’t be a food source for mold so that’s good.

One issue with thermal-mass is if it’s cold for a few days and then suddenly the air gets warm and humid. This can make an unheated space feel colder or cooler since a thermal mass will soak up heat if there’s no insulation on the inner wall and if there’s no furnace/stove heat source inside.  Worst case humidity could condense on an uninsulated thermal mass. It could feel a bit dank or musty at times, but mold-wise I’d guess probably wouldn’t be a health issue for the average person.

For a passive (energy saving) system, condensation on the thermal mass could in theory dehumidify the air and make it more comfortable.
On a water-repellent surface maybe the condensation could be drained away, however, I’d guess on a water absorbent surface having that liquid water in the structure would be unwanted.

If electricity is available, I wonder, maybe there’s a way to run an air conditioner to avoid condensation (by keeping the dew point below the thermal mass’ temperature).  To save energy maybe the heat from the back of the air conditioner could be pumped either outside or into the thermal mass whichever was cooler.

We will be using a wood stove for heat on really cold nights.  I had planned to insulate as much as I am able.  I had thought about getting a mini split unit to help with humidity.  As I said in the initial post, I am not even in the design phases yet because I want to address my concerns before I begin.

The thermal mass will be great for the summer, the temp doesn't even need to be lowered, but you might need to lower the humidity (by lowering the fan speed of your AC unit, or using a dehumidifier, venting the shower/bathroom/stove/oven, and using an ERV for makeup air (it will use the outgoing air to absorb some of the humidity of the incoming air).

Insulation: Insulation is great for the winter
Thermal Mass: The thermal mass means that you will not really need to lower the temp in the summer
Heating: PEX piping for radiant floor heating, coupled with a fireplace/RMH/boiler/mini-split.
Ventilation: I like a good Energy Recovery Ventilator it will temper the temp and humidity of the incoming makeup air
AC/Humidity: With the thermal mass there isn't a big need to lower the temp, but lowering the humidty (slow fan speed) will help alot

I woner if you could use the greenhouse effect to warm the house in the winter? And with pex piping in the floor that heat by the windows could be transfered throughout the house. There must be some software to model this. Maybe all the plastic insulation isn't needed.