Earth bermed earthbag

I've been thinking about building an Earthbag home, was wondering if building into a hill making an earth bermed house would work with earthbags? I'm in central Texas and have sandy soil.......would doing a rubble trench work for foundation? Right now interested in seeing what would and wouldn't work and figuring cost.

I'm a great fan of pure earthen buildings, but I've always understood that for the underground or earth bermed part, you need to use something that can't turn to mud in case the ground gets wet or damp. Our school is all rammed earth and adobe brick buildings with the north side bermed into the earth, and that bermed north wall is always made of stone in our case. I have seen people write of rammed earth foundations, which I think are stabilised with cement, but I've never actually seen them.

I also have to say that in terms of thermal comfort, the earth bermed walls are okay, but really not perfect. In our region, the ground temperature is in the 50sF, which is nice and cool in summer, but chillier than you really want as your whole north wall in winter. One the other hand, the thick earth walls are just terrific, and I would strongly encourage you to go through with that. Whether it's rammed earth or cob or adobes or earthbags, it's got wonderful properties of insulating and thermal mass, as well as being acoustically pleasant, moderating humidity, and a certain coziness.

[Spellcheck doesn't recognise "bermed" -- phooey! But it prefers -ise to -ize.]

Im interested in earthbags because of being cheap and easy....what about trenching? How deep does it need to be and what size rock or pepples need to use? Also on north wall being in the hill, would it being curved help in strength or would it matter?

A curved retaining wall would definitely be stronger than a straight wall, depending on the curvature in proportion to the wall's thickness. At ordinary house and masonry dimensions, it would be worth doing if you like the curved wall esthetic.

It'd be best post pictures of a water jar soil test at the different levels that you would be building at (are you gonna cut into the hill and be partly below grade as well as bermed--daylight and walk out on the south side?) also a picture of your land, drainage, rainfall...
Berming would be a good strategy in your climate as far as thermal performance. Can you get some road base or clay to cut into your sand for bag fill. What's your drainage like? Maybe consider some French drains and a vapor barrier...
As far as structal retaining worthy design--curving, battering back into compacted backfill, or even interior posts tied into rafters can all be utilitized. You have a rough design? About how sunk and bermed?
Chris

The hill isn't that big, roof line would probly be just above hill.

As for drainage, I'm pretty sure Im gonna have to do a french drain. Still working on design but north wall will be into hill probly about 5 or 6 feet down and south will be open. Could use help with design but budget is tight, still have a lot of things to figure out.....

Rebecca Norman wrote:I'm a great fan of pure earthen buildings, but I've always understood that for the underground or earth bermed part, you need to use something that can't turn to mud in case the ground gets wet or damp. Our school is all rammed earth and adobe brick buildings with the north side bermed into the earth, and that bermed north wall is always made of stone in our case. I have seen people write of rammed earth foundations, which I think are stabilised with cement, but I've never actually seen them.

I also have to say that in terms of thermal comfort, the earth bermed walls are okay, but really not perfect. In our region, the ground temperature is in the 50sF, which is nice and cool in summer, but chillier than you really want as your whole north wall in winter. One the other hand, the thick earth walls are just terrific, and I would strongly encourage you to go through with that. Whether it's rammed earth or cob or adobes or earthbags, it's got wonderful properties of insulating and thermal mass, as well as being acoustically pleasant, moderating humidity, and a certain coziness.

[Spellcheck doesn't recognise "bermed" -- phooey! But it prefers -ise to -ize.]

I've been trying to figure out a way to combine the Earthship concept in with a Cob/Earthbag House! I want to have a Small Greenhouse in the front, like an Earthship uses, to continue growing foods that are "out of season" in the Winter, and cannot grow in Cold Temperatures. However, I had heard that a Greenhouse put onto a Cob House would overheat the house, and a Berm wouldn't be good for the Walls. I never thought to think of using all stone for where the Berm would meet with the house!

Would using stones where the berm meets on a Cob or Earthbag house, allow a Greenhouse to be added? Or would there be other issues of having a Greenhouse in a Cob/Earthbag building?

What is the best earthen mortar to use to seal the stones together, without using Cement, and won't be affected by the berm? Would Lime be ok to use in a mortar like this?

This is what we're building:



I think that building earthships with earthbags is a great combination.

Robert Shear also built an EB earthship. He has a series of videos on youtube:

Rebecca Norman wrote:I'm a great fan of pure earthen buildings, but I've always understood that for the underground or earth bermed part, you need to use something that can't turn to mud in case the ground gets wet or damp. Our school is all rammed earth and adobe brick buildings with the north side bermed into the earth, and that bermed north wall is always made of stone in our case. I have seen people write of rammed earth foundations, which I think are stabilised with cement, but I've never actually seen them.

I also have to say that in terms of thermal comfort, the earth bermed walls are okay, but really not perfect. In our region, the ground temperature is in the 50sF, which is nice and cool in summer, but chillier than you really want as your whole north wall in winter. One the other hand, the thick earth walls are just terrific, and I would strongly encourage you to go through with that. Whether it's rammed earth or cob or adobes or earthbags, it's got wonderful properties of insulating and thermal mass, as well as being acoustically pleasant, moderating humidity, and a certain coziness.

[Spellcheck doesn't recognise "bermed" -- phooey! But it prefers -ise to -ize.][/quote
very old post do you have any examples of a stone berm wall? i was wanting to do the same

mike hillerer wrote:very old post do you have any examples of a stone berm wall? i was wanting to do the same

Hi Mike! Our bermed north walls are just the same as the external retaining walls, but plastered. So they're not really easy to show in photos. When we were building the original buildings of our campus in 1990s, it was all drystone work. If you click through the link in my "signature" you'll see photos of our school's campus but I don't know if you'll be able to pick out the bermed walls or retaining walls.

In any case, here in the Indian Himalayas, stone masonry is popular, and stone masons are an affordable part of any building project. This might not be the case where you are. I'm not a mason myself and wouldn't try to give any advice about stone masonry. Only this: I think the bermed wall should be made of stone or concrete bricks or poured concrete, or anything else that won't turn to slush when it gets damp or wet. If it is bermed into a hillside, the wall may be subject to lateral load, especially during events where the ground is getting soaked, which is when the hillside tends to slide down and your wall may be damp. Of course all the time, the wall may be holding up the roof load, including the maximum snow accumulation you are likely to get. So calculate for both of those issues.