How much you paying for bales?

Hi Permies,

I just check a local strawbale distributor here in Kansas, USA to compare. http://www.honeydewhay.com/

He wants $5 for a 14" x 18" X 36" bale. If I did my math right to covert the 14" x 36" or ~500/144 sq-in or 3.5 sq-ft. That's $5/3.5 or ~ $1.50 sq-ft. That's 3X fibergass ($.50 sq-ft) or mineral wool (roxul) $.70 sq-ft both @ R-15.

What is the r-value of this stuff for codes and certification (energystar, LEED, etc) ?

Hay was stupid expensive, but has come down to just crazy expensive. Very few actually do straw bales, so they can charge pretty much what they want. I know I had $.40 into making a square bale just in fuel and wire (wire is 20 cents per bale!, twine is 6) and that is for an extremely fuel efficient tractor, not including labor or machinery depreciation/upkeep or transport. Figure those in and $5 a bale is not losing money, but not gouging either.

You are not doing a true cost comparison, as the bales also act as the studs and sheathing in most timber frames. You need to go all the way to finished cost before you can get relative comparisons.

Bales cost as much as $9 apiece here. The cheapest are 4 and that's if you buy a bunch and you know the guy.

A few places here are either out of straw all together or they are charging 11 dollars and change for a bale. It's a pretty loose bale too. Not something I would consider building with.

I think I can get my bale cost down to $3-4. Looks like some of you can design to cost using other local abundant sources. I’m also having a hard time finding green wood, local trees, and a saw miller. R-Scott you know where to get them in KS? Are you following IBC/IRC 2006? I did a search and cannot find bale code. I talked to our AHJ here and we have a couple homes for prescriptive path but no bale code at all. I told him I could bring my plans, code from other jurisdictions, and since I am an Engineer I can explain my load paths and r-values. He said I may not need a PE stamp which I don’t have. Hope it works, and with the raters I am trying to get third party certification from (Energystar, IAQ, LEED. Then there are the appraisers, banks, and insurance underwriter hurdles since I am a builder.

Yes I see the bale can take and sustain structural loads if designed correctly. I just put this together this morning based on research, I have not built one yet but am seriously considering it for production building’s, pro’s, con’s, things to consider to accumulate cost. Some of the cost replacements bales provide are hard to put a value on or people fail to.
Please feel free to let me know if I missed something,

Load Bearing “Nebraska Style” Bale – Natural Builder’s answer to SIP construction…

Pro’s
• Potentially no vertical wood so less wood cost, no double structural/insulation duty bales.
• Average 75% reduction in utility cost compared to lite wood construction and 3X r-value.
• Monolithic for better load transfer.
• Buckling is reduced with an increase aspect ratio (width to height, 14” x 18”, closer to double stud ratio) vs 2x4 or 2x6 stud walls.
• Better sustainability.
• Bale low modulus of elasticity and elastic deflection are good for lateral live loads(seismic, snow, and wind).
• large pore size of tubular stalks reduced capillary action (wicking potential) while still providing good thermal resistance. Less likely to wick into walls. I read r-values of 3x standard construction but am not sure where to get them. I think it depends on density and packing the installation, staggering.
• Stiff(cement based) skins can be designed to react vertical compression (dead and live, weight) loads to the foundation.
• Ductile bales aid in distributing compression loads to shear at the bale-skin bond lines. If a ductile plaster (vs cement binder) with less lap shear strength is used (such as clay) to carry this load, less tensile cracking will occur but, the skin will not carry high loads. The bales will have to carry the compression loads.
• Lots of empirical data and history, walls still standing after centuries, for descriptive code. compliance.
• Bale wrap energy retrofit would eliminate insulation support structure (other than a raised heel footer(EG: double stud shelf, or gravel base to isolate ground moisture), Larsen truss or insulation cavities attached to sheathing not required)
• Cement skins need a rain plane or WRB since they are less permeable than clay breathes moisture/temp swings.
• Debris and storm damage resistant(wind, hail, tornado, hurricane, seismic).
• Sound proof
• Pest tolerant

Con’s or considerations
• Lack of manufactures steady state r-values for code compliance and certification raters that depend on density and quality of bales.
• Good for dry climates since bales can get wet during construction unless tented(giant tarp or circus tent)
• Cement skins if required structurally to transmit shear loads to the foundation (IE: two story loading, high wind). Corrosion stress cracking from tensile stresses can occur if the skins allow moisture/wind infiltration (use a WRB rain plane, siding, etc adds cost).
• Clay-lime wash stucco is better as a base coat due to its low elasticity, plasticity, interface to bales. Finish with structural cement as required.
• Water deflection and drainage is critical especially at base to fight erosion. Good idea to set bales on framing (that also provides an electrical chase). Protect walls against splash back from wind driven rain.
• Solid roof and foundation joints are critical for load transfer to minimize point loads.
• Large span timbers can be added to take loads at an increased cost, more along eves where loads are highest. Let in, out, or infill. Prefer let in to keep insulation continuous, enhanced air sealing.
• Fish netting can improve ductile tensile strength of skins and ties to roof and foundation sills.
• Straws biology and cellulosic cousin, wood, is plagued with a host of variables that affect its structural performance (mainly moisture).
• Lack of knowledge with code, banks, appraisals, RE agents, insurance. (not sure how many need to know what is inside the finish wall?)

Construction Notes:
• Bales must be kept dry during transport. Build the roof first, why most builders prefer added cost of post and beam wet climates. Hybrid wood and plaster design enhance aesthetics.

Terry Lee wrote: I’m also having a hard time finding green wood, local trees, and a saw miller. R-Scott you know where to get them in KS?

Those I have helped have had their own on-site timber. I have an Amish saw mill down the road from me and they can't get enough logs. Most of their logs come from Missouri.

R Scott wrote:

Terry Lee wrote: I’m also having a hard time finding green wood, local trees, and a saw miller. R-Scott you know where to get them in KS?

Those I have helped have had their own on-site timber. I have an Amish saw mill down the road from me and they can't get enough logs. Most of their logs come from Missouri.

I'll look into a little more but I'm thinking sourcing green lumber is not going to yield cost effective design in our neck of the no woods I thought KS is Z4-5, where is it in Z6? I'm in 4.

I was watching a video this morning from a book I am reading called "The natural Builder Companion" (great book) on load bearing bales in wet climates like ours. The biggest issue being keeping them dry and timing the construction to rain we get allot of in spring and winter snow. They have allot of wood in the NE where the authors are from and build the roof first then drop tarps from it. Circus tenting the whole envelope is another option until the roof and plaster is in but, sounds like a pain especially wind driven rain we get. So I'm leaning towards rammed earth columns despite being labor intensive to support the roof, infill with bales. In 4 I could probably run the bales on end(vertically) with a 14" thick r-value infill wall, 24" RE columns. I think the formed square columns look great with curved bales, perhaps some 6x6 interior wood supports.

Anyone know of a good roof system that has mass and would be tornado/debri proof? I know the ICF builders are starting to pore pitched concrete(http://www.liteform.com/Lite_Deck/information.html) in wind storm alleys, is it possible to form an earth wall other than berm or earthship?

I am in SE KS, near Ft. Scott. Most of Kansas is zone 6, with the very north being 5b. Although, waking up to frost this morning (May 16) makes me think we are in 4!

R-Scott: What zoning map you looking at? http://www.google.com/imgres?imgurl=&imgrefurl=http%3A%2F%2Fwww.bdarchitects.com%2Fbd-MAP%2F2012%2F04%2F12%2Fcondensation-roundup%2F&h=0&w=0&tbnid=_D_wo-YD7xYEiM&zoom=1&tbnh=175&tbnw=287&docid=2_MATk4LAmWW0M&tbm=isch&ei=_gt2U77QA8SaqAbitYDoBw&ved=0CAIQsCUoAA

http://planthardiness.ars.usda.gov/PHZMWeb/

I see thats USDA for ag. ICC & IECC for building code and energy compliance we are in 4.


http://www2.iccsafe.org/states/virginia/Energy/PDFs/Chapter%203_Climate%20Zones.pdf

http://energycode.pnl.gov/EnergyCodeReqs/index.jsp?state=Kansas

yup, hence the confusion.

Well good news is massive bale walls will work in building code zones 4- 6 ....As far as a live wall, got me? I'll get into the agriculture once I got the place built

Rammed earth columns? Wouldn't it be easier to make compressed earth bricks and build the columns with them? They can be reinforced with rebar and whatever to make them stronger. Possibly lower costs for equipment if you can rent the machinery.

Terry Lee wrote:
He wants $5 for a 14" x 18" X 36" bale. If I did my math right to covert the 14" x 36" or ~500/144 sq-in or 3.5 sq-ft. That's $5/3.5 or ~ $1.50 sq-ft. That's 3X fibergass ($.50 sq-ft) or mineral wool (roxul) $.70 sq-ft both @ R-15.

What is the r-value of this stuff for codes and certification (energystar, LEED, etc) ?

Gathering this info myself now. Per this, R-value for straw bales is 26-30 for an 18" thickness. So based on your comparison, it's about twice the R-value and twice the cost of Roxul (aside from 4x the wall thickness). So almost equivalent except that you have to factor in the lumber cost saved and also the actual lesser R-value in the Roxul scenario due to the wood framing. Still, personally I don't see a compelling reason to go with straw bale yet ... If anyone has info or links that would help me understand why straw bales might be more economical, I would appreciate it. (I understand it is more eco-friendly)

"Testing for R-value has been conducted several times. Only a few tests of full-scale walls (rather than bales) have been conducted (by Oak Ridge National Labs and the Technical University, TUNS, of Nova Scotia). The R-value for these walls were found to be between 26 and 30, about double that which can be expected from a wall built to most code requirements. (Note that a 2x6 wood frame wall with R-20 batts has an R-value of about R-13 when the thermal bridging through the studs is considered). Strawbales are comprised of over 90% air voids, easily connected to one another." https://buildingscience.com/documents/digests/bsd-112-building-science-for-strawbale-buildings

Digging up this thread from a while ago.

Have any permies done a recent cost/analysis with straw bale pricing vs Roxul? I’m surprised/shocked at how much straw bales cost where I live, and it’s putting the whole idea of it being a cost effective method of building out the window.

Any recent insights appreciated.

Ron Tam wrote:

Terry Lee wrote:
He wants $5 for a 14" x 18" X 36" bale. If I did my math right to covert the 14" x 36" or ~500/144 sq-in or 3.5 sq-ft. That's $5/3.5 or ~ $1.50 sq-ft. That's 3X fibergass ($.50 sq-ft) or mineral wool (roxul) $.70 sq-ft both @ R-15.

What is the r-value of this stuff for codes and certification (energystar, LEED, etc) ?

Gathering this info myself now. Per this, R-value for straw bales is 26-30 for an 18" thickness. So based on your comparison, it's about twice the R-value and twice the cost of Roxul (aside from 4x the wall thickness). So almost equivalent except that you have to factor in the lumber cost saved and also the actual lesser R-value in the Roxul scenario due to the wood framing. Still, personally I don't see a compelling reason to go with straw bale yet ... If anyone has info or links that would help me understand why straw bales might be more economical, I would appreciate it. (I understand it is more eco-friendly)

"Testing for R-value has been conducted several times. Only a few tests of full-scale walls (rather than bales) have been conducted (by Oak Ridge National Labs and the Technical University, TUNS, of Nova Scotia). The R-value for these walls were found to be between 26 and 30, about double that which can be expected from a wall built to most code requirements. (Note that a 2x6 wood frame wall with R-20 batts has an R-value of about R-13 when the thermal bridging through the studs is considered). Strawbales are comprised of over 90% air voids, easily connected to one another." https://buildingscience.com/documents/digests/bsd-112-building-science-for-strawbale-buildings

Straw bales are going for $8 at my local grain place.

Here straw is $6 and hay $8