written by Rene K. Mueller, Creative Commons CC BY NC 2014, 2015, last updated Fri, April 14, 2017
Most up-to-date entry at top, first and oldest entry at the bottom respectively last page.
A small side project: earth oven, next to the cabin:
- subsoil (beige colored) collected around the cabin (below the brown humus), soaked in water for 1-2 days
- mixed with a bit sand and straw, stamped with the feet until it was keeping form while still be formable (no photos as my hands were full of earth)
- used some cardboard boxes, cut into shape so a nice bow room achieved, second box for the front, taped together
- apprx. 5-6cm thick layer plastered around the form
- apprx 2-3 hours preparation, 1.5 hours plastering and mixing 3 batches on a piece of tarp
I let it dry for 2 weeks and then fire the interior, and it will burn away the cardboard - update posted later.
Nature changing now quickly: warm weather with a bit of rain.
Nature, here north of Switzerland, seems 1 month ahead of its usual schedule.
An excerpt of 25 photos of a sequence taken 2017/03/05 ~12:45 every 30 secs
Sunny day 2017/03/05
After weeks of sub-zero Celsius all day long, it rather quickly jump to 5-10°C, and today reaching 15°C - usually end of February is the coldest time of the year here at north of Switzerland.
Also most of the trees and bushes have been trimmed, some longer straight branches I put aside for some new smaller constructions:
- bow based tent-like shelter
- small tipi
Asleep garden (February 2017)
New projects . . .
The last days below zero Celsius during the day, some snow fall (~5cm / 2").
Cold dry weather doesn't affect the strawbales, so I don't expect any significant changes during the next weeks and months.
I've have been pondering on invest some more time to improve the cabin the coming spring:
- plaster the interior: reduce interior dust, brighten the interior
- get electricty from the grid (apprx. 150m away)
- heat transfer to store energy (warm water or electricity)
The last days below zero at night (frozen ground) and rain during the days (4-6C).
With the additional floor insulation it feels warmer, temperature droppings and raise aren't so quick, but actual detailed temperature measurements required.
The garden has calmed down, flowers and grass stopped growing; the cut apart left over slowly decomposing.
Two years ago around the same time I just finished the built of the cabin itself, it was mild and dry before it began to rain.
Photo: November 19, 2016 - around 15:30 already in the shadow of the trees / forest in the west, sun not yet set over the ridge farther west.
Last night rain turned briefly into snow, just a bit of snow - a few patches over the grass, which melted during the morning away; 6 weeks earlier than in 2015.
I decided to upgrade the floor insulation for this coming winter 2016/2016 with 35mm thick pressed china grass insulation (198cm x 35cm or 28cm),
it is solid enough to serve as floor without additional wood. I also insulated the door with the same parts.
Additional 35mm thick Floor Insulation
I harvested the rest from the garden (pumpkins, tomatoes) and removed the small tomatoe shelter, 1/2 of the tomato harvest didn't finish to ripe on-site but now in the warm kitchen.
After weeks of warm weather the temperature fell from 25C to 15C rather rapidly within 1-2 days, and regular fog in the morning arrived.
Not much rain yet which otherwise is usual in October and November in this region.
The exposed raw strawbales doing fine after nearly 2 years, another month the 2nd anniversary is reached when I will take detailed photos of the strawbales again.
The garden does well, so far the moisture of the ground is still sufficient for the garden - no additional watering was required so far - posting photo as comparison for previous month.
Until ~14:00 the the sun doesn't reach the front of the cabin, and it's nicely cool inside the cabin, yet, once the sun reaches the front the inside warms up significantly, through the windows (the shades are inside).
Summer has been hot and wet, the surrounding has been blooming, grass has grown significantly compared to summer 2015.
The grass around the cabin slowly reaches the strawbales, and insects might more easily reach the bales - so I likely will cut the grass around.
Also the small garden began to do well, planted vegetables are growing well - assuming the soil has been balancing itself:
- tomatoes: growing well
- potatoes: growing well
- zucchini: late planting (seed into the soil) grows well, others vanished and did not grow well
- rhubarb: growing slow, next year possible to harvest, not this year
Since the soil in front of the cabin is humid I did not have to water the garden at all.
All 4 photos were taken apprx. 1.5m off the ground:
West side (sunny)
North side (shade)
East side (shade)
South side (shade)
There is a slight dark shade on the strawbale, at the close up the "shade" is made up by small dark spots on the straw.
So the change is very minimal, more long term exposure is required to estimate the longevity of the bare strawbale cabin.
Btw, the green tone of the "East side" comes from the grass behind the cabin reflecting green to the strawbale wall.
Looking at photos of last year around May 2015, and one sees how fertile and green nature looks around.
The grass is high and dense.
After a period of 10 days with a lot of rain and lower temperatures of 10-15°C sunny days with up tp 25°C.
I started a small garden in front of the cabin, but the earth with horse manure isn't mature yet for vegetables:
- rhubarb: does well
- squash/pumpkin: too early to tell
- zucchini: doesn't do well, some leaves turned yellow despite sufficient water in the ground, new leaves are green again
- tomatos: too early to tell
each bed has 3 layers
- sand/earth mix layer at the bottom
- horse manure mixed in
- loose straw on top
the base is a moist or wet ground.
I began to prepare some garden beds in front of the cabin as I thought to take advantage of the muddy and humid ground.
Since the cabin is located on the west slope, the sun reaches the roof and garden beds around noon - will see how it does once I planted some veggies.
I also collect some rain from the roof, yet, without dedicate rain channels as for now.
Between March 23 and April 12, just 3 weeks, the change in nature is significant:
- in the background the forest is significantly more green
- the grass in front of the cabin is grown significantly
The last weeks it remained 5-10°C during the day, and a few times below 0°C.
For 1-2 days it snowed ~5cm but melted away right away - the winter skipped, and spring time coming slowly.
Rotting strawbales due leak of the covering tarp
Some of the strawbale I piled up outside covered with a tarp I checked, and some began to rot due a small leak of the tarp - so I had to dispose the bales and scattered the open straw near by to provide some soil soon for gras on the slope behind the cabin (see photo).
One remaining pile of strawbales seems doing fine.
I leaned a small wheelbarrow on a pile of covered strawbales, with apprx. 5-10cm space between bales and the wheelbarrow - it began to rot just at that space; microclimate with lack of proper air circulation seems to affect bare strawbales greatly.
April is a rainy month in central Europe - so once April and part of May passed I photograph the bales of the cabin close-up and compare with previous photos I made.
Mid of February, and the past weeks hardly any snow, rarely below 0C, more humid and rainy wheather. The straw is still doing fine as far I can tell, but will review carefully when spring approaches and temperatures raise over 10C.
About 10 days ago we had a winter storm "Susanna" approaching from south-west, 80-100km gusts over period of ~18 hours on and off, and the cabin maintained itself.
After warm and humid (rainy) weeks finally the temperature fell below 0°C and snow fall started.
The straw on the north side is a bit darker due the humid weeks - will see if it will reverse due the drier and colder days ahead.
The mild fall has continued, hardly any rain; the small upgrade I did a few days ago paid off, less mice on the roof as they used the gap to explore the top of the cabin.
Since the fall has been so warm, so little rain, the strawbales aren't really tested much in regards of mold.
A bit more than a month until lowest sun path (December Solstice), before the daylight extends again.
After a hot summer, with days with over 35°C and hardly going below 20°C at night, fall approached, which until November did not have a lot of rain but quite some foggy days around 5-10°C.
I noticed the northern side of the cabin slightly darker, with some slight mold; the west and southern side still like color as in the summer.
A small "upgrade" I did a few weeks ago: closing the gap at the back (east-side) just at the roof/wall junction, which otherwise was open straw compressed between the ceiling beams, and now a ~6cm line of wood:
The straw did quite well through the winter and spring, humidity did not affect the straw as far I can tell.
The rest of the summer was rather hot, up to 38°C for days, very unusual for this region.
Snow is gone, the dome I had to take down as the snow and storms - so far the cabin did very well through the winter time,
let's see how the rest of spring time will affect the exposed straw bales.
A low pressure system with strong winds and rain went over the region last night, and decimated most of the snow, but left the soil very damp.
The temperature raised up to ~8C° in the sunshine. The snow which slid from the roof remained in front and in the back.
The gas heater I obtained isn't doing the expected: it heats the air quickly, but it won't last due the minimal thermal mass as I realized. The insulation of the cabin isn't as tight as I planned (still needs work), but this is just part of the problem.
A real oven radiates the heat off its thermal mass, and carbin monoxide mostly exits through the pipe, whereas the gas heater leaves carbon monoxide inside the room and needs proper supervision.
So a real oven would have been more suitable, even for just 2-3 months use during winter time, after that it won't be of use for me.
Ideally would be a light stove with sufficient thermal mass, e.g. using water for the thermal mass instead of heavy stones.
- Gas Heater: very light (2kg), inexpensive (EUR 70), no pipes, easy source of propane gas (11kg = EUR 20)
- Ordinary Oven: heavy (80kg mininum), variable price (free - EUR 600), requires pipe system, easy source of wood (1 ster = EUR 50)
- Light Oven: light, inexpensive (DIY), requires pipe system, easy source of wood (1 ster = EUR 50)
1 ster = loose 1 m3 wood
A "Light Oven" I envision a brick based rocket stove, which can be assembled on site and disassembled when taking down the habitat again, and only transport the pipe system.
The thermal mass would increased with heat resistant water canisters positioned close to the oven.
Next Page >>
- Page 1: Plans, Numbers, Material, Reflection
- Page 2: Diary, 2017/04/12: Earth Oven (1), 2017/04/09: Spring, 2017/03/05: Sunny Day, 2017/02/23: Pre-Spring ...
- Page 3: 2015/01/03: Snow Slide Down, 2015/01/01: New Year, 2014/12/31: Week with Snow, 2014/12/27: First Snow ...
- Page 4: 2014/11/18: Sorting Strawbales, 2014/11/14: Planning Procedure, 2014/11/12: Planning the Walls ...