Hey Bulldog
New member
Elsewhere on the forum, there was a discussion about circular yurt walls made from strawbale. The sole problem I can see is: plastered strawbale walls won't flex like lattice. And that's what I'm planning. Have worked with several books over the last couple years; I write assuming a forum reader is unfamiliar with straw bale building, so pls forgive my pointing out some bale concepts. Also- I have very high anxiety/OCD and am a beginning builder.
I get cold easily. But can't build a "permanent" structure (zoning). And a deck won't work for me either (heat loss and pests).
Planned: a 22' diameter (if all goes really well). With ~15" thick walls of straw, a 22' diameter round has a 19'-6" inside diameter, and ~298sf, or about the floorspace of a 20' ger with a lattice. I will lose some floorspace to a cold-protective entryway. I am living in a house right now,but would love to finish before December- it's a toxic house (allergies).
So the plan: stemwall is built of courses of earthbags (stabilized soil), to keep the bale wall, min., 12" off the ground and dry. The nice thing about bales is that I can BEND them easily to form a perfectly circular wall (stomp on them in a trench). Plastered on both sides, they make a stressed-skin panel, which is very strong. Similar to a roundhouse, but the yurt roof is easier.
I found a yurt book in which the author (Lee, 2013) built them with an outer perimeter of narrow rectangular framed sections, connected, rather than a lattice. He claims that they hold up well to Manitoba winters (!) on his homestead- with 110mph winds. How cool is that.
My idea: use a similar framing system, but within the bale wall instead. Bales as infill accommodate framing well). Note- pounding rebar down through bales is now considered a poor idea: leaks= structural fail over time. The wall is ~5'-4" tall, depending on flooring.
Site is a little remote, on a slope, using hand tools only until I get a generator. Remote enough that a driver dumping off gravel would refuse, and drop it below on the lawn. So I have to haul materials up there. But- gentle south-facing slope, so it's worth it!
I'm still undecided on the floor finish- bales, and plywood? earthen??
Stress!!! Detailing and planning to beat back the swarms of carpenter ants here. GRRRR.
--> An innovation: at the top of the alternating-course, plastered bale wall, pour a ~4" thick bond beam of concrete etc., as is done with earthbags (bent horizontal rebar within, to strengthen it). This avoids having to build a super-strong wooden top plate over the bales. It should be able to resist both lateral and compressive forces in a windy place (~60 mph max). Critical: wood framing or posts within bales must then be able to support both bond beam and (fairly light) roof. I'm planning with the help of several books- Myrhman/Bergeron on straw, Hart on earthbags). But am new to carpentry.
Then build yurt roof above bond beam. Anchor all rafters to bond beam with hurricane ties or similar. The wall cover piece, fastened to the roof cover above, covers the exterior of this bale wall. I already have a cover from Groovy, and have heavy sewing machine to alter it, or make other covers.
The structure will include a complex insulation plan to minimize condensation (Lee's book), and create a shallow frost-protected foundation (Roy).
I will need really good ventilation also. That's why the ring-and-skylight is appealing. I'll be off-grid, so a passive system is best until I can power 12V vent fans. But I need to keep enough heat inside too.
So in short: a hybrid, proportions like a Mongolian Ger. I may do something radically different from the typical crown, though (like a commercial light tube and lots of vents). I'm trying to balance the needs of our ~4 very warm months against the ~7 cold ones (zone 5).
I remember Knecht's cool build, and the tragic mold problems which resulted when he didn't vent it very well (?)
For the first winter, those small diesel heaters look like a good bet. But I then can't crank up a stove to "cook off" mold until I install the stove or RMH. And the flue.
-->If anyone knows strawbale renders: What is the minimum plastering, on exterior of wall, necessary to get the insulative benefit of bales? Could I get away with just a clay slip, maybe mesh for support, if I built the 2x4 frames (covered in tarp fabric) around the perimeter, and just pushed the bales up against them? If this is possible, I may not do the cast bond beam. It wouldn't kill me to build a wooden one. But situation is a bit urgent.
-->Cold-weather dwellers (zone 5 & cooler): Having to tie an urgh (hat/cover) over the skylight isn't a deal breaker- but the acrylic dome sounds more convenient. Except that I've seen on here that it can freeze open in winter! Yipes! What is an appropriate skylight or other for off-grid, winter weather? Can it clear out stale moist air better than a suntube and several vents?
--> Does the strawbale wall sound feasible?
I have a Sketchup model if images would help. Thanks in advance!
I get cold easily. But can't build a "permanent" structure (zoning). And a deck won't work for me either (heat loss and pests).
Planned: a 22' diameter (if all goes really well). With ~15" thick walls of straw, a 22' diameter round has a 19'-6" inside diameter, and ~298sf, or about the floorspace of a 20' ger with a lattice. I will lose some floorspace to a cold-protective entryway. I am living in a house right now,but would love to finish before December- it's a toxic house (allergies).
So the plan: stemwall is built of courses of earthbags (stabilized soil), to keep the bale wall, min., 12" off the ground and dry. The nice thing about bales is that I can BEND them easily to form a perfectly circular wall (stomp on them in a trench). Plastered on both sides, they make a stressed-skin panel, which is very strong. Similar to a roundhouse, but the yurt roof is easier.
I found a yurt book in which the author (Lee, 2013) built them with an outer perimeter of narrow rectangular framed sections, connected, rather than a lattice. He claims that they hold up well to Manitoba winters (!) on his homestead- with 110mph winds. How cool is that.
My idea: use a similar framing system, but within the bale wall instead. Bales as infill accommodate framing well). Note- pounding rebar down through bales is now considered a poor idea: leaks= structural fail over time. The wall is ~5'-4" tall, depending on flooring.
Site is a little remote, on a slope, using hand tools only until I get a generator. Remote enough that a driver dumping off gravel would refuse, and drop it below on the lawn. So I have to haul materials up there. But- gentle south-facing slope, so it's worth it!
I'm still undecided on the floor finish- bales, and plywood? earthen??
Stress!!! Detailing and planning to beat back the swarms of carpenter ants here. GRRRR.--> An innovation: at the top of the alternating-course, plastered bale wall, pour a ~4" thick bond beam of concrete etc., as is done with earthbags (bent horizontal rebar within, to strengthen it). This avoids having to build a super-strong wooden top plate over the bales. It should be able to resist both lateral and compressive forces in a windy place (~60 mph max). Critical: wood framing or posts within bales must then be able to support both bond beam and (fairly light) roof. I'm planning with the help of several books- Myrhman/Bergeron on straw, Hart on earthbags). But am new to carpentry.
Then build yurt roof above bond beam. Anchor all rafters to bond beam with hurricane ties or similar. The wall cover piece, fastened to the roof cover above, covers the exterior of this bale wall. I already have a cover from Groovy, and have heavy sewing machine to alter it, or make other covers.
The structure will include a complex insulation plan to minimize condensation (Lee's book), and create a shallow frost-protected foundation (Roy).
I will need really good ventilation also. That's why the ring-and-skylight is appealing. I'll be off-grid, so a passive system is best until I can power 12V vent fans. But I need to keep enough heat inside too.
So in short: a hybrid, proportions like a Mongolian Ger. I may do something radically different from the typical crown, though (like a commercial light tube and lots of vents). I'm trying to balance the needs of our ~4 very warm months against the ~7 cold ones (zone 5).
I remember Knecht's cool build, and the tragic mold problems which resulted when he didn't vent it very well (?)
For the first winter, those small diesel heaters look like a good bet. But I then can't crank up a stove to "cook off" mold until I install the stove or RMH. And the flue.
Questions for the (patient) crowd: opinions?
-->If anyone knows strawbale renders: What is the minimum plastering, on exterior of wall, necessary to get the insulative benefit of bales? Could I get away with just a clay slip, maybe mesh for support, if I built the 2x4 frames (covered in tarp fabric) around the perimeter, and just pushed the bales up against them? If this is possible, I may not do the cast bond beam. It wouldn't kill me to build a wooden one. But situation is a bit urgent.
-->Cold-weather dwellers (zone 5 & cooler): Having to tie an urgh (hat/cover) over the skylight isn't a deal breaker- but the acrylic dome sounds more convenient. Except that I've seen on here that it can freeze open in winter! Yipes! What is an appropriate skylight or other for off-grid, winter weather? Can it clear out stale moist air better than a suntube and several vents?
--> Does the strawbale wall sound feasible?
I have a Sketchup model if images would help. Thanks in advance!
