Steel bale?

This is just a thought, I am curious to explore the pros and cons:

Can one use straw bale in combination with a steel frame? I am referring to use a prefabricated steel kit, and steel roof but without the steel siding. Then use straw bale, plaster as walls. Since straw bale walls are 16 or 24" thick, those big steel frames will be embedded into the straw bales and pretty much invisible inside.



-Typically, folks use concrete slab for this type of building, would typical slab work with SB?
-I guess one would need additional eaves.
-Any worries about where straw touches the steel frames?

Hello Rose,

Yes, it can be done, but breathable wall assemblies like straw bale, should have only breathable materials in them. Steel is a great thermal conductor and so will be colder than the other materials inside the wall assembly, so moisture will condense there and possibly rust the frame. For less money and the same amount of time you could build a pole barn style structure with wood which will outperform and outlast a steel frame.

All Blessings,
Bill

Morning Bill, I guess if high ceiling and wide open space were the requirement, then steel frame may be more cost effective than timber post and beam? But you are right, condensation may be problem. What if this steel and bale would to be used in extreme hot and dry climate say Arizona desert? Where the steel frame will be hotter than the surrounding straw bale during the day time but colder than SB at night? With overall low humidity, would SB do well?

Hello Rose,

I would second Bill's observations...

This is a matter of "making something work" when there are perhaps better and easier alternatives.

Metal is a major component in much of modern architecture, and like re-bar and other steel reinforcements in concrete is also often a challenge, as here too it leads to moisture issues that erode the steel, which in turn exfoliates and scalds the concrete. It seems like a good idea, and has become a common practice to use steel in much of modern building, yet everywhere steel is used, be that re-bar in concrete, or modern steel bridges and so forth, there is evidence that it has challenges many did not expect, nor is it proving to be as "durable" as society had hoped.

I can say that steel is "fast" and as such seems economically a good idea, yet if sustainability or long term durability are part of the equation, then perhaps there are better materials?

With these consideration taken into account I think a wood frame is much better around natural materials as most current good builders of SB architecture will not even use metal lath for the plaster, or re-bar for pinning bales. Only wood and other natural materials are employed.

Rose Gardener wrote:What if this steel and bale would to be used in extreme hot and dry climate say Arizona desert? Where the steel frame will be hotter than the surrounding straw bale during the day time but colder than SB at night? With overall low humidity, would SB do well?

It could actually be a larger challenge than one might think, even in a dry climate, as it is the "interstitial" buildup of moisture coming from the living space that is the contributing challenge, not the moisture outside per se. Metal just isn't recommended with SB and other natural materials...as I understand it or have experienced.


Regards,

j

If you are doing good generous overhang for the roof, those beams will be outside the straw wall, like a column on an old mansion. The bale house would be free floating inside the pole barn, sort of house inside a house.

Hey R. Scott,

That could be one way of "making this work."

If the bales didn't have any steel at all in them and the outer steel frame and roof structures was indeed forming a shell over the SB house, then I don't see why it wouldn't work, Perhaps being aesthetically not as pleasant as an all natural build might be a reason, but that is a subjective view on my part... The next thing to look at following this suggestion would be an actual comparative cost analysis and long term projected viability between a nautical SB build and one incorporating a steel building.

Regards,

j

The steel bale idea is a bad one, unless a beal home inside of a steel columns. But what's the point? Since we are thinking outside of the box, let's put the SB outside of the steel column,

As long as the SB don't rest on concrete, are at least 500 mm above grade, have no steel inside of them or in contact and the roof overhangs are large enough to mitigate splash up or over wetting during rains, then "making this design work" is still within the realm of plausible. Next just compare the economics...

Rose, i might send some mad, but instead of steel, for large spans like this, you could use laminated beams. I've seen 18m long lately, which were about 6 inches thick and a yard high.

http://www.gate-project.org/gallery-image.php?src=lluniau/estoniafg043.jpg&caption=Glulam+beams%2C+Estonia&text=Laminated+beams+at+the+Puhajarve+Health+Spa%2C+Estonia

Hello Rose,

I built a 60'x100' steel structure like this with my dad 20 years ago for an indoor riding arena (my parents raise and train Paso Finos) and after that all of their friends wanted me to build similar barns for them. I found that I could build a pole barn with wood posts and "LVL" beams, through bolted together for less than just the price of the steel kit. Once the poles are set, a structure like this goes together in a weekend.

Also it is much easier to facilitate the tie-in of the bale infill with a wooden frame.

All Blessings,
Bill

Bill Bradbury wrote:Hello Rose,

I built a 60'x100' steel structure like this with my dad 20 years ago for an indoor riding arena (my parents raise and train Paso Finos) and after that all of their friends wanted me to build similar barns for them. I found that I could build a pole barn with wood posts and "LVL" beams, through bolted together for less than just the price of the steel kit. Once the poles are set, a structure like this goes together in a weekend.

Also it is much easier to facilitate the tie-in of the bale infill with a wooden frame.

All Blessings,
Bill

Hey Bill, How much would it cost to have do a 50x80ft, 14ft tall with LVL? I guess we can do a 2/12 pitch roof? I think the steel kit with roof plus roof insulation and erection would be about $25-30k or so plus the foundation cost.

Hi Rose,

I'm sorry, but I have never built a wood framed barn that big, so I really couldn't estimate.

I would guess that you could not build a pole barn of this magnitude for less than that. The largest pole barn that I built was 24x72 and cost about $12,000 in materials.

All Blessings,
Bill

Thanks Bill, sounded like steel would be cheaper but just can't combine that with straw bales.

I am also considering this type of build since I already have a steel skeleton. I think that Rose has asked the question better than I did in my previous query but I am not giving up yet. How about another type of infill like papercrete or fibrocrete? Or something else? So, would it work with the steel on the inside just as well as having it on the outside and perhaps covered with some type of aesthetically pleasing material encasing the steel posts? How about an airspace between the steel and the infill and the steel then covered with a siding material? I have DIY skills and wont be hiring much help just an electrician and some occasional muscle. I am able to build a timber frame house. I have done it before but I would rather use what I have.

Kat, I think some sandwich type approach may work, (per drawing) but not sure why one would be doing it? As steel siding + foam or fibre insulation could achieve similar insulation without the potential pest issues.

My steel is 2 1/2 inch tubular and the building frame is 20x30 feet so it will be a tiny house. This makes for a strong frame but not enough space for insulation. Straw bales will take up too much interior space so I was considering fibercrete blocks (homemade from some source of cheap fiber and cement). These blocks are R-2 to 3 per inch, strong and hard enough to need a chain saw to cut. They could be stacked and mortared together with more fibercrete outside and inside of the steel frame all on a foundation of rubble topped by cinderblock filled and rebarred and a wood top plate. I need to use a strip of foam wherever the blocks, cement or steel contact Spray foam from a can is also an adhesive and that would be a good thing too and it would fill in any tiny gaps. A wood bottom plate on top of the cinderblock would also allow me to bolt the steel frame into that as there is a bottom rail in this frame. I could attach a wood top plate on the blocks and attach the same wood top plate to the steel. I could leave the steel frame as airspace thus sandwiching the steel frame between fibercrete walls. The fibercrete would be top coated with mortar of some type. If each block is 6" thick, that would give me an R value of at least 24. I wonder if this system would keep the steel warm enough not to weep and if this would be a breathable wall. The contact between cement and steel and fiber and steel is interrupted by wood and a thin layer of foam. I am trying to limit the amount of wood, cement and foam from the build and reuse as much as possible. I have heard that foam off gasses and is not green in general and is expensive too. So, as long as cement doesn't touch metal and metal doesn't touch fiber with wood as the chaperone can they still be friends?

Hi Folks,

As I follow along, and per other conversations, I want to sound positive, while being clear about what I understand and know of this medium. Steel is not the most enduring of materials as many believe it to me. There is now clear evidence that wood outlast and endures steel over time and even in fires, if we speak of large timbers.

Even our steel bridges are showing severe signs of stress and fatigue and the concept of "painting them" has only encapsulated the necrotic effect of oxidation, and hides it from view. Where certain bridge have found a formulation of paint that is "somewhat" effective, in these cases it must be constantly inspected and replaced on a regular bases. Little has actually surpassed the simple function of "bare metal" oiled with flax oil, and left to easy drying and weathering. When metal is treated in this fashion it appears to reflect better endurance.

So, for the sake of being positive about the use of metal over wood structural methods, I would like to suggest the metal be well under the drip line of the roof, just like wood. It also benefits from either being inside the thermal envelope or exterior to it...completely. Any attempt to encapsulate is a recipe for un-inspectable structural comprise over time. If you can see the metal...there will be challenges in time that we can not either see, or address appropriately.

So, as long as cement doesn't touch metal and metal doesn't touch fiber with wood as the chaperone can they still be friends?

Hmmm...I am not sure cement is friends with very much of anything...

What is important is not to encapsulate the metal and keep it as segregated as much as possible from all other building materials. So, it can sit on a foundation of cement if it must, but should be viewable and inspectable all the way around.


Regards,

j

Hey Jay,

For our education, a few generic questions about SB:

1. Straw:
What's the optimum straw for SB building? Rice etc?
2. Compression:
Compressed SB, any particular compression or method are more desirable?
3. Moisture:
What's the optimum moisture in SB?and how could one ensure all bales are the same?
4. Wrapping material:
I assume we need some sort of metal wire or mesh wrap to prevent rodents. Multiple layers of small hole mesh or a mix of some sort? Mesh for both inside and outside?
5. Bugs:
How does one prevent that? Ants would be too small for mesh to handle.
6. Electric wiring:
Conduit or romex? As wires heats up some under load, any worries?
7. Water pipes:
Can one run them inside the SB? Even insulated pipe would introduce some temperature issue and condensation, right?
8. Concrete:
Why can't the SBs sit on concrete foundation, raised perimeter or slab?
9. Eaves:
Can one build SB home in a Santa Fe style ie no eave?
10. Internal walls:
Any reason to or not to use SB for internal walls?
11. Air quality, any pros and cons?
24. Wall thickness
SBs are 16"x24" footprint, aren't they? Any reason to go for a 24" thick wall vs 16" other than additional R value?
25. Roofs:
For SB homes with a pitch roof to meet modern insulation code, what would be the most workable insulation? What about a flat or minimum pitch roof in case of hot climate?
26. Any tie downs or some sort be necessary between the SBs and wood post/beam structure? or just stack SBs between the posts?

haha, that's all this ignorant can think of at this point.

Yikes Rose...I do my best...

Understand that these are just a view based on working, with, for about SB methods, as well as, a few decades of correspondence and research with other builders.

1. Straw:
What's the optimum straw for SB building? Rice etc?

Barely, rice, wheat...in that order, though baled cotton, felted carpet padding, buckwheat hull, reed, hemp, and a few others that escape me at the moment also show great promise.

2. Compression:
Compressed SB, any particular compression or method are more desirable?

Depends on the harvest, the machine and the intent. I am personally not particular, and believe that simple compact bale form that stays integrally together is more than adequate in most applications...Yet, I don't condone "structural" SB for the most part, as too many DIYers do have the skill sets that "think" they have or have been lead to believe....There is just too many "mistakes" taking place out there in the natural building world currently and more each year...None of which does any of us any good for the cause.

3. Moisture:
What's the optimum moisture in SB?and how could one ensure all bales are the same?

Below 20% minimum and dryer preferred. Testing and/or a reputable source for the baled materials. Proper storage and treatment is a must.

4. Wrapping material:
I assume we need some sort of metal wire or mesh wrap to prevent rodents. Multiple layers of small hole mesh or a mix of some sort? Mesh for both inside and outside?

No...not metal at all next to the bales...ever!! This is one of the most common issues and even done by many "professional" SB builders. Rodent and insect proofing can be done (needs to be done??) perhaps in some areas, and metal screening is incorporated in those "exclusion methods" yet the scope (and location with in the wall matrix) is beyond a simple post like this.

In most cases if the structure is designed well, and sits on a proper foundation with good finish treatment (ie. plaster, wood, etc) inside and out...rodents and other "wee beasties" are not going to be an issue in most situations...

5. Bugs:
How does one prevent that? Ants would be too small for mesh to handle.

Other treatment methods and I think I have described many of them here on other posts....IF...they are even an issue in the first place as most are not, and only a perception...or human discomfort with being around them...

6. Electric wiring:
Conduit or romex? As wires heats up some under load, any worries?

No, yet the electric and mechanical harness for a structure should be well designed and planned out to have ease of access....I don't bury these in wall (especially a bale wall) like many do.

7. Water pipes:
Can one run them inside the SB? Even insulated pipe would introduce some temperature issue and condensation, right?

I won't do this...others can if they choose.

8. Concrete:
Why can't the SBs sit on concrete foundation, raised perimeter or slab?

9. Eaves:
Can one build SB home in a Santa Fe style ie no eave?

I don't do architecture without eaves unless of a vernacular design of such like Pueblo, Zuni, Hopi, etc....then if I was doing that...I would be working in timber, stone and clay...not SB....

10. Internal walls:
Any reason to or not to use SB for internal walls?

Not necessary...

11. Air quality, any pros and cons?

If a good design and build...then excellent...otherwise...??

24. Wall thickness
SBs are 16"x24" footprint, aren't they? Any reason to go for a 24" thick wall vs 16" other than additional R value?

Bales can come in a myriad of size. Fiber orientation is what I find to be very important to final function. I want any "stratified" fiber types that are "straw like" to be running in an "inside to outside" format and not perpendicular with usual paths of gases/vapor exchange. One dries well the other can "rot out" in time...

25. Roofs:
For SB homes with a pitch roof to meet modern insulation code, what would be the most workable insulation? What about a flat or minimum pitch roof in case of hot climate?

Mineral wool is typically my "go to" for fast and effective, yet there are many others and roof pitch is so dependent on so many things...design, biome, site location within a biome, etc.

26. Any tie downs or some sort be necessary between the SBs and wood post/beam structure? or just stack SBs between the posts?

Yes...pinning and tie down both...Yet being the end of this post, I should state that I would usually shepherd a client towards something besides SB unless a farmer next door (or very very close) is growing it and harvesting it in a good fashion...

I think there are other, and perhaps better straw based methods than SB itself...but that is a view I myself can vacillate on depending on situation...

Regards,

j

Thanks Jay!! Learned so much. What were you referring to when you said "better straw based methods than SB itself" and why are they superior to SB?

Sorry about that...I meant like "straw clay infill methods" for timber frames and related structures. It is a form of traditional insulative "cobbing" that was use in colder climate "wattle and daub" methods around the globe...

Why is straw-clay superior to straw-bale? I can see that SC walls aren't as thick as SB, so some space saving. Probably less opportunity for pest to invest. But the building process seems to be a bit more complex, building forms, mixing clay+straw instead of just stacking large bales. Does SC provide better R value or sound insulation?

Since I am planning to live in warm country, winter 65F+, does SC provide anything SB couldn't under that kind of climate?

Thanks again for educating this ignorant.

instead of just stacking large bales.

Ah...there is the rub...good SB architecture is so much more than "just stacking large bales," so the comparatives have to be well understood and worked with to really get a handle on the logistical, structural and performance related benefits to each. In your case, I probably wouldn't employ SB, and instead look to the local vernacular systems for the region you are moving to.