John Lint

I live half way up a rather large hill the frost heaves affect our entire usable yard most of spring making it a bad place to plant new fruit trees especially sensitive ones like asian pears. Where the yard meets the hill a thicket of mostly hemlock with a few pine and birches mixed in. These trees are vary densely packed about 1-2 per 2 square foot. Since I can't grow fruit in the yard (for fear of frost killing flower buds) why not cut down the trees and plant something edible? The plan is to plant 2 or 3 different kinds (for pollination) of each apple, asian pear, peach, and mulberry. Hopefully all this wood can be used to heat a greenhouse if not it will be put to good use elsewhere.

It's doubtful removing half an acre of trees or more importantly tree stumps could be done by hand by myself without the help of some sort of machinery. What would be the most cost/time effective way to accomplish this task? Also any advise on fruit trees for zone 5 would be appreciated.

Suki Leith wrote:You might consider stone slabs with cement grout. Stone has a higher thermal mass than soil. In Korea, prior to hoops houses ( and arguably better, in my opinion) they made their greenhouses with underfloor ondol heating, the flues being made of stone. Rocket mass greenhouses use the same idea. Here's a photo of one as they are still being used in North Korea. This one is earth bermed as well.





As for soil cement. I am anxiously awaiting geopolymer cement to get approved and have its mass production worked out. It chemically hardens earth to harder than cement and will be a much greener solution. There's a company in Oakland, Ca. which has major financial backing and it looks very promising!

Really cool pictures Suki would totally love to have a greenhouse that big. Out of curiosity what is the climate in North Korea? The only thing about stone is I'd have to buy em' that or dig the entire yard up. Last year we dug a 10x50' garden area the yard is full of small and medium size rocks about as large as your hands folded together into a ball shape. It does sound like a good idea if a free source of largish rocks can be found. Do you happen to know the name of the company? Here's an awesome product for people in Aussi land
http://www.youtube.com/watch?v=eNO88AcJ60o

Edit: Embedded video

R Scott wrote:Well, that is my non-green plan, at least for the earth contact parts. I will do limewash on the interior and above the splash line so it can still breathe, though.

Is a lime wash water proof?

Another non green idea... Could one make adobe or cob then coat the outer walls and/or parts in contact with the soil with liquid rubber? $40-50 at home depot gets a 5 gallon bucket of rubberized roof coating. One or two bucket normally does a entire trailer roof top so there would be enough to do a few coats all the way around a cob/adobe house depending how much surface area is being covered. One or two buckets max for the common one room cob featured on youtube most often. It's the stuff they use for the top of mobile homes to seal up any leaks in the roof. My only concern is sometimes on really hot days that stuff can stink pretty bad (if in direct sunlight) or at least the cheap stuff does. No one really likes the smell of burnt rubber lol but it just might work. Oh man so much thinking today my brain hurts.

R Scott wrote:I hate earthquakes. Zero warning. Even tornadoes have some warning--enough to put you on alert, anyway.

The footwell pit for the oven also will act as the cold well (per Oehler's design) so I would probably do it if I could.

Cob ovens are AWESOME!!! If I build another house, I am really tempted to use one as the "fireplace." RMH and cookstoves are more practical, but the way the fire dances in a cob oven is particularly mesmerizing--it dances in slow motion in the dome.

Here is a thread with more on insulating slabs: https://permies.com/t/10424/earthen-floor/Cold-climate-foundation-choices

The goal is to isolate the mass of your floor from the outside freeze line. You can put the insulation down or out (umbrella) to keep the floor and mass closer to the earth core temp.

Thanks for the thread haven't had achance to read it yet from the title though sound like it should be a major help.
All this is so confusing. Really I don't understand most of it other than the slab need to be protected from the frost heaves... Even worse is I tried talking to contractor friend to get a better understanding he couldn't even fathom houses being made from soil cement or cob.
I had been wanting to build a small test hut on the edge of the property next summer if there were a surefire way of weather proofing it. Snow is heavy and moisture sure would be an issue.
The greenhouse is the main concern though everything else is back burner for the moment.

Which would you say is more sturdy cob or soil cement? Do the two even compare? Is lime plaster even waterproof? I have actually done some googling on this stuff so it's not like I'm blindly asking beginner questions. (not insinuating anyone thought that either) From the literal hundreds of video's I've seen on cob and other natural building materials 99% if not 100% have been in a desert so trying to adapt things to a climate like we have is a bit different. For example cob alone wont cut it maybe a mixture of cob with cement added to the mix might.

Back to cob ovens for a moment. Have you seen this video? double chamber cob oven it has a chimney and an air intake why couldn't it be used as a fireplace with a ton thermal mass stacked around it? Maybe not as efficient as rocket stoves yet if you get a nice glass door for it then you've got a pretty damn stylish fireplace. Sure the exhaust is straight up instead of weaving through a bunch of cob like in the benches everyone makes. This would have the added benefit of doubling as an oven or rather doubling as a fireplace whichever way you look at it.

Any thoughts or considerations are greatly appreciated.

John Polk wrote:If you click on your "My Profile", it will open it.

Below the name/password info, there should be 3 headings.
Click the + sign on the left of "Preferences", and it should open up the menu where notification options are.

Awesome found it. Thanks a bunch!

R Scott wrote:Basic blue or pink foamboard. No, it is not "green" but in the scheme of things it will do more good than harm as it will save you and the environment a lot in heating and emmissions from your stove. You could use lava rock, perlite, or any other recycled insulation--but you will get water conduction that a solid slab will prevent.

here is a link for the cob oven in a greenhouse: http://www.small-scale.net/yearofmud/2011/11/03/killer-wood-fired-pizza-oven-design/

A good cob oven is great for holding and releasing heat SLOWLY. You could fire it up at night and it will heat all night and be nice and warm in the morning still.

Not everything in this build had to be 100% green so I'm totally ok with that. Dude that cob oven is freakin awesome! Although it probably would have been better to build some sort of rock/brick/something platform for it to sit on to avoid having to dig a hole to stand in but hey if it works it work right. OK so let me get this straight rough steps would be dig down under the frost level, fill the space with foam polystyrene ect, poor the soil cement slab on top, build the greenhouse, and finally build the cob oven. Sound about right? Might have to look into concrete posts instead probably would be cheaper since foam cost a lot if bought new... Heck this sparks some new ideas for sure.

Weird thing today Maine of all places had a 4.5 earthquake I'm located about 20 miles away from the heart of where it erupted from (not sure if that is the correct term or not) the house was shaking tv's nearly falling off the stands all I could think was I'm having a heart attack, the house is going to implode, or the hill is disintegrating and forming some kind of rock slide it was both my vary first earthquake and quite the fucked up experience...

Most forums have a settings or control panel where you can turn off and on certain features. Dunno if I'm blind or not but I just can't find the option on these forums. Anyways I'd like to switch off the function that emails me every time someone replies to a thread.

R Scott wrote:I have messed with soil cement. It is a good way to mud-proof a walking path. It doesn't change the mass over plain dirt.

I would rent a trencher and dig a trench around the perimeter and put down blue foam as deep as you can get. That will isolate the mass inside from the frozen ground.

I have seen youtubes with rocket heaters, barrel stoves, and cob ovens all used to warm a greenhouse. I would use the RMH or cob oven based on what you can get for wood to feed it.

What is blue foam? Yes I have seen quite a few youtube videos about RMH's, Rocket stoves in general, and only one or two on cob ovens which are of interest as well. As far as fuel goes I've contacted a local lumber company to see if they will give away saw dust and wood chips which can then be compressed into logs/bricks for burning. Hopefully they say yes because the place is only a 5 min drive from home. Also have family members that can get free pallets from work. This is vary much a low budget building endeavor except the greenhouse itself that will be expensive it has to be to last the winters we have lol.

leila hamaya wrote:i have worked with soil cement, but not necessarily looking to it for thermal mass for a greenhouse. what i have found is you need a lot more cement to soil than many recipes call for. of course it depends on what the "soil" part is.....urbanite, broken smashed concrete, is also a good addition to this kind of mix and you can get it for free, though it requires some looking around and a lot of sweat to gather it.

i think your plan is sound, in my (unexpert but studied) opinion =)
sounds good.

an idea that i have had about heating in a cold climate is to do a bowl shaped design. basically digging out a large bowl in the ground and placing the hearth in the center of the area that would be underground. and there would be levels that rose up from there...

if the door was raised from ground level by some steps inside and out there would be less heat loss through it.
well just some thoughts, not sure if thats of help to you...doing something partially underground.

How far down would you dig? The frost level here is 4 1/2 feet down so can't really dig that far.