Eino Kenttä

Hey everyone, thank you so much for all the awesome input (and for being awesome in general, of course!) To answer your questions:

John C Daley wrote:There are a number of questions I need to ask first?
- what thickness of earth do you wish to support?
- How will you prevent the soil sliding off?
- have you looked at wofti homes?  

-We're thinking 10 or 15 cm on the main (less steep) roof, thicker on the sides and back where the turf will support more of its own weight.
-The turf will go all the way down to the ground on three of the sides, and on the sides and back we plan to lay the turf sheets horizontally and "staple" them together by pushing sticks through each layer into the one below, to stabilize it until the grass roots have had time to do their thing. So the idea is that the lower turf cover stops the upper turf cover from sliding, much like on a natural hill.
-I'm a little bit unclear on what distinguishes a wofati from other types of green-roof buildings. If I've got it right, the layer of soil would be quite a bit thicker than on traditional turf roofs? Given how much it sometimes rains in our area, I don't think I fancy trying to build a wooden structure sturdy enough to hold up a meter of soil...

thomas rubino wrote:
I have questions also...
Where will the RMH sit?
Will it be a simple J-tube or a longer-burning batch box?
Do you have bricks?
Did you know that once you heat with bricks, you will never go back?

-It'll be in the back right-hand/middle part of the "main roof" area as seen from the front, the chimney will exit just to the left of the peak of the roof.
-Right now we're planning for a first-generation batchbox, but still open on this.
-We do have bricks, not quite enough yet, but we'll get more. We also have clay on the property, so planning a double-skin bell with an outer skin of cob.
-So I've heard, and really looking forward to proving it right

Jay Angler wrote:
I am no expert either, but the fact that you have vertical supports within the structure, improves my confidence.

There are other ways to make sure you're safe from a night time collapse - like a traditional medieval bed that is like a cupboard with a roof on it!

It would be a lot of work, but if you added extra posts in between to reduce that gap from 100 cm to about 50 cm, that would make a big difference.  I don't know how rot resistance spruce is, but with 50 cm centers, there'd be more redundancy if one of the posts went bad.

We're planning to put the bed in the back, where the roof is way steeper. The back row of posts is also a bit thicker than the rest, so we feel reasonably safe. Also, we won't sleep there the first time it's subjected to heavy rain or wet snow. We'll observe it carefully for a while after finishing and see how it holds up.

We are considering extra posts along the sides just to make sure, but like you say it's a lot of work. We also have a few other methods for increasing stability in mind. We'll see how it turns out in the end.

Josh Hoffman wrote:
Unfortunately, the standard that covers log construction/connection, ICC 400, does not have any reference tables and would require an engineer run the calcs and stamp the design.

The IRC has tables on sawn members but the spacing is 24" max and I don't think the dead load table for areas with lots of snow would be something you could compare.

I think the ICC has a section covering green roofs but again, they want you to engage a design professional.

I would trust it if someone with experience in log construction/connection and green roofs looked at it and said it was okay. This person does not need to be a design professional, just someone with experience, maybe someone on here has that skillset/experience.  

We're in contact with the municipality people to get it approved. It seems like there won't be a big issue, they're giving us some very good suggestions. Also, we do know some people with experience in this, and we'll definitely ask them as soon as we can get them to come out here. That might be a little while, since our place is a tad remote, but hopefully before it's time to lay the turf.

Anne Miller wrote:That roof does not look very load bearing to me.  It looks like it is missing some support beams.

I have read that turf roof weighs a lot.

To support our drywall ceiling we used 4 x 4 support beams.

Yeah, these pictures are not entirely up-to-date. We've added some beams, started the second-layer structure now, but I don't have the pictures of that available at the moment.

Rico Loma wrote:What method are you using for connections
Dowels, lag bolts, a mixture of methods?

The connections between the posts, main beams and knee bracings are mortise and tenon. Everything else is done with wooden dowels. The construction feels solid, doesn't move at all when we climb around on it, but you don't really need that much turf to weigh the same as a person...

Hey knowledgeable people! Me and my partner are building a small roundwood post-and-beam cabin in our forest. Up until now we've been mainly playing around because it's fun, but now we've reached the point where we want to make it official. The plan is to put a turf roof on it, which will go all the way down to the ground on three sides. The fourth side (facing south) will be a cordwood wall with windows and door. My question right now is about what kind of load-bearing capacity we can expect from the roof? Will it be enough to carry the weight of the turf?

The sides and back (which are steeper, see pictures) don't really worry me, since more of the weight will be supported by the turf itself. The main roof, however, is less steep (the angle is about 31.5 degrees). I don't know nearly enough about these things to say for certain if it'll be okay. My gut feeling is that it'll work out, but I'm not an engineer and neither are my guts.

The material used is Norway spruce. There will be horizontal beams (which aren't there yet) running perpendicular to the roof beams to distribute the weight, which in turn will be covered by spruce poles and/or split planks. The span between the posts is about 100 cm in the east/west direction. In the north-south direction the span is about 150 cm, but reduced by knee bracings, so longest unsupported span is about half that. The span between the first-layer roof beams is about 70 cm. Span between second-layer horizontal beams yet to be determined.

So, what do you all think? Any input would be very welcome.

Thom Bri wrote:I often lay stones on top of pots of seeds. The sprouts come up between the stones, and the squirrels can't get at the seeds.

Okay, now that's brilliant! Simple and elegant. Thank you!

M Ljin wrote:This brings up an interesting point.

I remember reading some Vermont history about how the Abenakis—and most indigenous groups—intentionally kept their populations at around one fourth of the land’s carrying capacity so that if they faced hardship they wouldn’t have to starve. And mostly it worked!

But there is also the element of caring for the land and not exploiting the land in horribly devastating ways. We have tested this earth to the breaking point and if things are extremely difficult then it’ll be no surprise.

That's super interesting, and makes so much sense! I assume that was one-quarter of the carrying capacity of the land when eating their preferred foods, rather than things considered "famine food"?

One almond tree in the ground, looking happy so far, we'll see if it manages winter at 64 degrees north... The other plant and all the sprouting seeds were found and devoured by a squirrel soon after putting the pot outside. It also bit the top off the surviving plant. Oh well. Next time I'll try to sprout them longer in advance, so there's no tasty nut left to attract rodents once they go outside.

From what I've understood, invasives are often most problematic in the early stages (relatively speaking) of their introduction into a new place. After a while, they tend to start accumulating predator and disease pressure, and lose some of that competitive edge that make them a problem in the first place.

I remember reading a study about garlic mustard somewhere in North America, where they found that in several locations it had increased exponentially after introduction... and then declined. Another example of the same thing, though anecdotal, I've heard from my grandmother. In her younger years, she watched lupines (highly invasive here) more or less entirely take over many roadsides and meadows, and then die back. This is in southern Sweden. In the north, where I grew up, they are still in their expansive phase. I suppose they were probably introduced a bit later farther north. We'll see if they follow the same pattern here.

Given this, keeping them down a bit and giving native species a chance in the meantime sounds like a good strategy. After all, if you somehow managed to totally eradicate an invasive species from an area, you'd also set back any local accumulation of pests and diseases that might have taken place to square one, and give the invasive a fresh start once it came back. So, well done Laurie, keep up the good work! (And enjoy all that free biomass...)

Good points, all. For me, the big game changer was learning about the trench method. Before then, I tried a few times with various methods of the "make a fire and then deprive it of oxygen" variety. It invariably ended up producing a little bit of char, a lot of half-charred wood, and massive amounts of extremely foul-smelling smoke. I had started believing that making "proper" char was either very hard, or very labour-intensive, or else required a lot more equipment than I was prepared to get. Then, I saw Skillcult's video on the trench method, and since it looked very doable and required no equipment beyond a shovel and a bunch of water, I tried it. I've kept doing it ever since.

Edit to say that the climate around here is wet enough that a big, open fire is no issue. We mainly make char on lightly rainy days, to make sure it won't spread. In a dry climate, some form of retort might seem like a more attractive option.

How about horseradish? Some animals might nibble very young shoots (our plants were eaten down this spring, I suspect the deer) but they are vigorous enough to keep growing anyway. If they like your place, they might expand and possibly compete with the "weeds", although the American goldenrod species do seem to be very tough...