Vertesol Eustache

Daniel Andy wrote:I'd like to be able to grow some tropical trees in south-central canada. In a greenhouse.  I've seen it done with styrafoam, but I want to do that in a natural building context.

I want to build a greenhouse to do that and use strawbale around timber structure for it straw's insulation properties.

I am concerned about high humidity (a result of warm temperatures and frequent top-watering on wet soil in sun) and its effects on a strawbale wall system.

As it's canada and cold/dry...a significant amount of condensation on the windows is to be expected, even if they are doubled.

I could do a lot of drip-sill installation under each window to ensure condensation coming off it doesn't go onto the walls below, but is that even approaching enough? There will be plenty of moisture in the air, and watering, wet leaves, and air flow is sure to throw additional liquid onto the walls as well.

I am concerned that a high humidity greenhouse with lots of condensation seems like it might be a poor fit for strawbale, and I should look for less water-sensitive wall compositions. Is that right?

I'd like to stick within natural building but I'm not sure i have the years required or the team of people I would need to build a cob wall of sufficient thickness for a greenhouse. I'm not sure what other natural building approaches I can take that combine insulation with water resistance.

Actually, I do think your worried. A damp greenhouse situation is really hard on strawbale in the long term unless the moisture details are extremely well thought out.
It may be to your benefit to use a more moisture resistant building material for the greenhouse itself and use strawbale for adjacent, dry building elements.

Thorsten Bux wrote:Hi there,

we have a tree line of about 6-8 quite mature and high cypress trees. During the wintertime, they shade the lawn and house area quite noticeably.
We are wondering if we could cut them down to about 2/3m height and use the remaining trunk as posts for building. We came across something called a snag to start planting and using the area again.
Does anyone have any experience and suggestions on what to do and how to best approach the project?

Many thanks in advance.

Sure, you can but cypress trunks which should stand like a post will probably rot gradually f you don't take care of them.
Many people pull them all up or leave a few for wildlife snags, planting around the orders.
If you want to use the trunks for structure, make sure they are around dry and well sealed.

C. Letellier wrote:Combining a recent you tube video discussing vibration compaction talk about it staying compacted long term with how our first cistern growing up was built.

The compaction video basically said ground compacted properly under buildings was basically the same as piles.  It didn't become uncompacted over time even with ground moisture.  Now I am sure freeze thaw would break it up but what about just water?

Top half of the first cistern in my life was a monolithic pour of the lid and about 4 feet of walls as the top half.  The lower half was a thin layer of concrete plastered over  the dirt.  Bottom half water held fine and worked but it was forever cracking at the joint between the 2 layers.  My parents never did get it sealed for any length of time so we only used the bottom half for the most part.

But what if the thin concrete went clear to the lid so it was a consistent material and the dirt behind it was vibrated or rammed earth thus heavily compacted?  Maybe cob with fiber glass or basalt fibers instead of straw?

The compaction of the earth will still remain, however, it is not a 'pile' and still expands and contracts with changes in moisture content. The failure of your cistern at the joint due to expansion/contraction differential plus shrink/crack of the eath itself, not compaction. A thin plastering over the compacted earth will never hold water for long, you require continuosly reinforced concrete or suitable liner.

M Ljin wrote:The last load of firewood came, astonishingly, with quite a large amount of flame birch, a kind of curly grained, shimmery yellow birch wood. I’ve been saving whatever pieces I see, either big ones for a woodturner friend or smaller ones for my own purposes. Something tricky about figured woods seems to be that they can’t be carved with ordinary knives, planes, and so on, as far as I can tell—do this and the grain starts to split. I have had success with files and saws so far, but maybe there’s something I don’t know.

How do you work with these difficult but beautiful woods?

Figured wood like that is tricky. Use very sharp tools, take light cuts, and cut “with the grain” constantly changing direction, or switch to scrapers/sanding to avoid tear-out.