roofs - no plastic

i'm looking to dig a small sleeping house into the side of a hill using 100% materials just laying around.  anyone done this before?  i never have.  my two main concerns are: 1. turning the house into a swimming pool because i don't know how to direct the water properly, and 2. going through all this effort only to have my roof melt away in the first storm.  i don't want to use a plastic liner on my roof.  there's got to be a way to make a roof just last.  i don't have a lot of grasses here, for thatch, but i have almost unlimited scrubby saplings that are pretty straight.  and clay.  lots of clay.  i'm wondering if i can just construct it, and put some grass/plant sod onto it. then when the grass takes hold the water will wick off?  is this a pipe dream?

Its very doable.

You would be best with stone, clay, 4 - 6 inch logs and a good slope.
The trick is rto ensure the walls dont collapse and stones are best for that.
Set on a good stone foundation first with gravel behind to drain water away from the wall and down the slight slope on the floor outside.
Lean the dry stone wall backwards abit for strength.
Use poles to set the roof in place and have it sloping so water will drain off away form the walls.
Then seal the poles with clay that will dry and not crack.
Cover that clay with rubble thats is small and could form a rammed earth style of consistency.
Then cover that with anything to stop erosion,  all the time keeping a good slope so water does not pool.

Mother earth example

In Kentucky, you are likely to get enough rainstorms that I would not expect the wicking/storage effect of sod to be sufficient. On the Great Plains or Southwest, maybe.

Do you have any flat stone available? Applying that over a well-sloped pole base might be adequate for shedding water seepage through a sod covering. I would put a second layer of "shingles" or a gravel drainage layer over the first stone layer, so you don't get water dammed up and backing up through stone joints.

Sod as a topping would help with erosion prevention, but it would also tend to hold the water on the roof to soak in rather than running off to the sides quickly. It all depends on how frequently and heavily it can rain as to which effect is more important. A shingled layer of flat stones on top of a well-sloped roof surface would tend to minimize water getting into the roof in the first place, which might be sufficient with a thick absorption layer to keep water from leaking inside. Grass would likely take hold in the cracks between stones over time and help hold the surface in place.

It would be easier in a dry climate. I doubt a sod or clay roof will be enough to keep you dry in a wet summer. It depends how thick you go, of course, but the weight of water saturated clay/sod is significant.

When you dig into the hillside, do you see thin seams of soft rock like shale? These naturally drain water horizontally. If you could dig under a shelf like that, you would have a natural roof.

We did something like you are thinking as a "guest house", but with our lack of topography and high water table we just built it and covered it with soil and sod/moss. It's held up well for the 5 years since we built it, although it needs occasional patches of sod added.

There's a brick-surrounded woodstove inside that easily heats it up and holds heat for the night, helped out by the styrofoam under the soil/sod. We spent 3 weeks camping in there with our two retrievers while we were moving our yurt (waiting for rains to end).

Michael, that's a pretty cool little shack. It looks like you framed it with wood and than added dirt and sod -- is that correct? I'll bet the steep slope helped a lot with rain. Do you have a sense of how deep the "wet" layer went?

The OP specified "only materials found on site." That's the big challenge here, I think. If (for example) sections of steel from discarded appliances could be used as shingles, or as a secondary water shedding layer, it would be easier to keep the inside dry.

Douglas Alpenstock wrote:Michael, that's a pretty cool little shack. It looks like you framed it with wood and than added dirt and sod -- is that correct? I'll bet the steep slope helped a lot with rain. Do you have a sense of how deep the "wet" layer went?

The OP specified "only materials found on site." That's the big challenge here, I think. If (for example) sections of steel from discarded appliances could be used as shingles, or as a secondary water shedding layer, it would be easier to keep the inside dry.

Thanks Douglas. I framed and sheathed it all with 2x10" rough lumber that was needing utilization. There are several inches of styrofoam over the top and walls which I got free from a hospital roof renovation, and for water repellancy I covered it with an old vinyl-coated transport tarp. I think this violates the "no plastic" criteria.

Michael Helmersson wrote:

Douglas Alpenstock wrote:Michael, that's a pretty cool little shack. It looks like you framed it with wood and than added dirt and sod -- is that correct? I'll bet the steep slope helped a lot with rain. Do you have a sense of how deep the "wet" layer went?

The OP specified "only materials found on site." That's the big challenge here, I think. If (for example) sections of steel from discarded appliances could be used as shingles, or as a secondary water shedding layer, it would be easier to keep the inside dry.

Thanks Douglas. I framed and sheathed it all with 2x10" rough lumber that was needing utilization. There are several inches of styrofoam over the top and walls which I got free from a hospital roof renovation, and for water repellancy I covered it with an old vinyl-coated transport tarp. I think this violates the "no plastic" criteria.

thank you, i'm not completely against foraging scrap here and there.  mostly curious if it's possible with a stick and daub situation.  thanks!! cool shack, i appreciate the pics

thanks for the ideas everyone, i'll have to see about finding some rocks, and see what it looks like when i dig down.  we'll see what happens.  i appreciate everyone's feedback

When excavating the hole, take some of the dirt and use it to raise the level around and above your shelter. Make sure the easiest path for water to take is away from you. I wish I could show you a picture of what I mean. I don't think I'm describing it very well.

You might even want a drainage channel inside the structure. That way if water does get in, it can get back out.

Multiple layers of mud and leaves should form a decent seal. But again, the main thing is to make sure that "downhill" is some direction other than towards your roof.

Ellendra Nauriel wrote: I don't think I'm describing it very well.

But again, the main thing is to make sure that "downhill" is some direction other than towards your roof.

I think that line was well crafted and memorable.