In the next few years, my husband and I will be building a smallish cabin (600-700sqft
footprint) on some property owned by my family in Cape Breton, Nova Scotia. The climate is pretty humid, wet and cold.
We plan to do a timber frame using timber from the
land, since there are around 160 acres and most of it is forested.
We will only have summers to work on it, since we will most likely still be living in Texas until the young'un graduates. And the distance (40+ hours drive) doesn't really lend itself to short, frequent visits. We have considered cordwood,
cob, and earthbag, but are heavily leaning toward
straw bale for its superior insulative properties. I do like the idea of light clay, but straw bales would completely enclose the structure, where light clay would seem to allow thermal bridging since it is just between the posts. Even though we're not sure we'll ever live there full-time, it's likely that we'll spend some time there most winters.
I am concerned about the longevity of straw bale in that environment. We are thinking we would orient one gable end wall toward the south and primarily fit it with windows. The idea is to maximize the
solar gain coming into the house, onto the packed earth floor, but also to minimize or eliminate the straw bale on the most exposed wall. The north-facing gable end wall would have either a dutch roof or
wood siding for protection from nor'easters.
Since we are hoping to use a packed earth floor and will incorporate a
RMH into the plan, we do not want a pier and beam foundation. I've found several discussions of raised earth foundations, but without much detail as to how to build one, and also rubble trench. Would this be sufficient to ward of moisture and termites? The frost depth there is 30-32". Rainfall even in July and August is 3-4". Prevailing winds are southerly - southwesterly, which means that's where most of the rain will come from. According to the provincial soil survey, most of the earth is "dark reddish brown gravelly clay loam till" with a slight W-E slope and moderate stoniness. There is running
water in the form of a small creek, which also means there is definitely sufficient dropoff to drain a rubble trench.
I
should add that I haven't been there in almost 50 years, since I was a babe. Around that time, my building inspector grandfather poured a trench foundation that presumably still exists, though I sincerely doubt it's in any condition to build on. It must surely be cracked all to hell.
This summer, my 2 kids (18 & 10) and I will be spending 6 weeks doing a sort of survey of the land, set up a suitable toilet and
shower situation, some type of rain collection, and a small
solar array to power the DIY solar generator we will build this spring. Two of those weeks will include my husband, too, but 18 and I will be doing the bulk of the work. If one of their friends comes with, we hope to also manage some type of tiny earthen building.
So, to recap, is a rubble trench foundation sufficient to keep a straw bale home dry? Is there a better option for walls I should be looking at? Is a wall of windows the absolute worst thing I could do?
pics attached:
Stream
Somewhere in the middle (courtesy of my sister's friend that visited last summer)
Google map of central portion with road frontage and existing clearing containing remains of a house and 2 trailers. Can you spot them? lol