# WWYD cabin build



## farminghandyman (Mar 4, 2005)

First I realize this is a double post, but thought I may get some different readers and answers here than in alternate energy only,

Not that long ago there was a thread called "*Frivolous homestead ideas" *Frivolous homestead ideas and I posted about a cabin I would some day like to build and since it a nice cold day I have been in the house thing some on it, 

Ok now the question, say I would build it and wanted a energy free building as possible but with he look as I have pictures for posted,
part of the problem is it would set empty most likely 90 to 95% of the time, and I would like as little cost in utilities as possible, to keep it above freezing and not like a sweat box in the summer time, and so if one needed to use it there would not be a long preparation time, 

I posted a thread on "Earth tubes" as a possible heat/cooling system at least when it was not occupied, (would think one would need more heat when living in it, 

what construction methods would you choose?

and other systems would you do?

even tho the grid is available an off grid systems would be considered, would like as energy friendly as possible, even if supplemented with the grid power, 
location, plains of Colorado (Normal max)lows -20 highs 110, winds up to 80 mph, and a lot of windy days,


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## dirtman (Sep 15, 2011)

Insulated concrete forms with a Drivit ( synthetic stucco) exterior. Super energy efficient, very little maintenance, Hurricane proof. Do the roof with 12" Trus-joist's and fill them with spray foam, or use SIP's. Standing seam metal roofing. A little pricey at the start, but will still be standing after everything else has rotted away.


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## Bellyman (Jul 6, 2013)

To moderate heat and cold, nothing beats thermal mass. Using the building itself can be one solution, walls, floors, ceilings, countertops, fireplaces... 

Concrete, as dirtman suggests, has a lot of plusses when using it as a building material, including structural integrity. 

Passive solar can generate a goodly amount of heat and if you have a way to store that, (thermal mass of some kind), you've got a good thing going!

Looking forward to reading as this thread progresses.


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## wharton (Oct 9, 2011)

dirtman said:


> Insulated concrete forms with a Drivit ( synthetic stucco) exterior. Super energy efficient, very little maintenance, Hurricane proof. Do the roof with 12" Trus-joist's and fill them with spray foam, or use SIP's. Standing seam metal roofing. A little pricey at the start, but will still be standing after everything else has rotted away.


 You ever see a Drivit (EFIS) building in the process of rotting to the ground since it wasn't done 100% perfectly and water penetrated the .......pick one. 
1. Window openings
2. Door opening
3. Deck flashings
4. Step flashing, board wraps at elevation changes
5. the other hundred ways an improperly installed job (read as 99% of all installations) managed to fail, and allow water to penetrate the highly absorbent substrate, cocooned in the water tight plastic stucco wrap.

Sorry, but it shouldn't take too much research to determine that EFIS systems are trash that shouldn't be allowed in most cases. At one point it was simply banned in some places, as new homes were turning to rotten mulch within months of being occupied. Seriously, it's really bad stuff. A totally watertight skin, over a sponge. What a mess.


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## farminghandyman (Mar 4, 2005)

the problem I see with thermo mass is it works just the opposite as well if it get cold it take for ever to warm back up, and if it is not keep warm to begin with, I have been in shops that when everything gets cold like it is right now in the west, below O, 
and it will take days to get them warmed up, if it is needed, 

as I thought about some type of rammed earth as well, but the same problem is there, 

thought about straw bale as well, (been wanting to get a small wire tie baler any way), but your just basically just super insulation, but is it cost effective, over standard insulation, of the same R value?

I like the little barn look, other wise I would consider a bermed structure possibly.

As said this is a dream but If I come up with a workable plan. I may start on it,


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## dirtman (Sep 15, 2011)

There have been a lot of bad Drivit jobs, but there is very little that you can put over foam. When we were building ICF houses your options were vinyl siding, metal siding, cement stucco or Drivit. Over foam there is nothing to rot and though most door and window openings are never flashed correctly, ours were. I take your point though that it is not a material for the untrained.


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## wharton (Oct 9, 2011)

dirtman said:


> There have been a lot of bad Drivit jobs, but there is very little that you can put over foam. When we were building ICF houses your options were vinyl siding, metal siding, cement stucco or Drivit. Over foam there is nothing to rot and though most door and window openings are never flashed correctly, ours were. I take your point though that it is not a material for the untrained.


 It goes WAY beyond the untrained. The big. ugly secret with that stuff is that the vast majority of it is improperly installed, inspected, or maintained. I spent a lot of my career doing institutional and light commercial work. In the 90s it became quite evident that EFIS failures in residential construction were become epidemic. I studied the issue and learned not only why they failed, but what details were required to do the work correctly. For them on, I was on countless projects from schools to hotels, malls etc... where it was clearly evident that it wasn't be installed properly, and nobody really gave a rat's butt hair. 

Since most installations fail, and foam is hygroscopic, and susceptible to insect infestation, IMHE there isn't a worse choice for an exterior finish on an ICF structure. That said, you literally couldn't talk me into building an ICF house if you dropped of all the blocks for free, but that's another matter.


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## vpapai (Nov 18, 2010)

Why do you have reservations about building with an ICF system?


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## wharton (Oct 9, 2011)

vpapai said:


> Why do you have reservations about building with an ICF system?


 Expanded polystyrene is beloved by destructive insects, IE carpenter ants, termites, etc... it is hygroscopic, it absorbs water and it will support mold. ICFs create a whole world of issues that are quite different than most standard construction details, and they are far from the easy peasy "easy as stacking Legos" B.S tale that gets told by their dealers and cheerleaders. To cover the next question, yes I have used them. Several times in my career I ran into. other builders who dove into the whole ICF game, and had convinced themselves that this was IT, the game changer. Well, in every case it took a year, or two, to get it out of their system, and they were back to doing it old school. IF they were everything that their supporters claim, they would have made a significant impact in the market by now, and in my region I see zero evidence that the system is more than a passing curiosity.


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## NorthernMich (Apr 30, 2006)

My house is ICF..........it's ahead of the game..


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## Tyler520 (Aug 12, 2011)

Solutions will come more from design than just material. You'll definitely need passive ventilation in the summers, so be aware of the local wind patterns and place openings accordingly. Make sure the slab is insulated and thick. Make sure most windows are on the south face...maybe going so far as to create a sun space - shaded by the roof overhang in summers, and allowing the sun to pour in during the winter to heat the slab and interior volume. Maybe even a clerestory window to get sun to the back of the home.

A few building material options available:

Metal siding on rigid foam on block walls, or light gauge steel framing...so long as you avoid organic building materials.

as for the concerns of rigid insulation, I have never encountered such issues - I hate to say it, but the single common denominator seems to be who the builder was.

Up-front costs might prove to be an issue, but long-term savings make it worthwhile


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## Pokletu (Aug 7, 2013)

Wharton,

You mentiond EPS as bad. Do you have experience with Expanded PolyUrethane foam? I'm looking hard at building using sips. Not touching the PolyStyrene anything. Are the -urethane sips any better, with any experience you might have with them?


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## gobug (Dec 10, 2003)

Carpenter ants will nest in EPS, but they don't love it. Termites don't eat it, they just go through it. Those are the only insects I know of that represent problems. 

Mold and fungal problems occur if there is not good surface coverage on all exposed surfaces. IIRC initial problems with EPS are related to the stuff being in direct contact with soil below grade. This can be solved during construction, not so easily fixed afterwards.

Bugs and many other pests, not just termites and carpenter ants, will cause complications with just about any building material. 

Drivit has many complications. If it is applied too thin, woodpeckers can go through it. Colors are hard to match for future routine repairs. It does not go directly onto the EPS, but onto an AR Mesh fixed to the foam. The wrong type mesh also causes problems.

Any shape made of foam can be coated with a cement recipe. Several coats make it very tough. Don't eliminate EPS or other foams from consideration due to the failures. I think this sort of failure is common with new processes, and not necessarily the final ruling. Just keep up to date.

SIP's are definitely an interest of mine, especially MgO covered SIP's.


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## PlicketyCat (Jul 14, 2010)

Passive solar with the right balance of thermal mass to insulation (area dependent) is the easiest free way to stabilize temperatures.

A bank of south-facing windows with an overhanging eave adjusted for YOUR solar elevation, or a pergola with perennial non-evergreen vines, or deciduous trees to shade the window in summer but expose it during winter. Super insulated building enclosure keeps the cool in during summer and the warm in during winter. Dark stone/brick/tile flooring to absorb and radiate solar gain heat during the winter, but remain cooler in the shade during the summer. Temperature-actuated (non-electric) vent openers and thermostatically controlled solar-powered attic & circulation fans work when necessary whether you're there or not (no sun for power also means no sun for heat!).

The actual building method and materials are less important than following good passive solar design principles FOR YOUR LOCATION. The seasonal mean temperatures, solar elevation and intensity, meterologic and geologic conditions in your exact location will dictate which design principles to apply and how much... there is no one-size-fits-all solution. A passive solar house in Arizona will be completely different than a passive solar house in Maine... you can't transpose them.

We've had good luck with staggered-stud double wall framing filled with dense-pack blown cellulose since we live where insulation is 100% more important than thermal mass. For us, with temps averaging -40 with only 4 hours of meager sunlight in winter and 100F with 24 hours of sunlight, lots of thermal mass works against you. You can absolutely never ever ever let the home cool down or it will be nearly impossible to get warm again during winter because the cold thermal mass will rob all your heat; and you can absolutely never ever ever let it get too warm in summer since there is no nighttime to cool it off. Lots of mass is also counter-indicated in most earthquake zones unless you want to spend extra on engineering and construction to quake-proof all that weight.


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## wharton (Oct 9, 2011)

gobug said:


> Carpenter ants will nest in EPS, but they don't love it. Termites don't eat it, they just go through it. Those are the only insects I know of that represent problems.
> 
> Mold and fungal problems occur if there is not good surface coverage on all exposed surfaces. IIRC initial problems with EPS are related to the stuff being in direct contact with soil below grade. This can be solved during construction, not so easily fixed afterwards.
> 
> ...


 Dryvit, or more correctly EIFS had been commonly used for three decades here, and longer in Europe, far from a "new process"

There is a long well documented history of EIFS failures in residential, commercial and institutional applications. It is hard for many outside the industry to grasp exactly how low the bar is set when it comes to workmanship, skill level, and even knowledge of the correct way to perform most tasks in the construction industry. The entire industry has migrated, by default, toward the solution with the best track record. The easiest, least skill and labor dependent process, and the one with the most tolerance for "user error" or a high rate of successful outcomes, even while typically ignoring best practice and failing to install per manufacturer's instruction.

EIFS installations are about 180 degrees out of phase with this concept. They require a high degree of experience, skill and knowledge to do well, and in a manner 100% consistent with best practice and AMI, or according to manufacturer's instruction. Consequently, the vast majority of EIFS installations are done poorly, and are beginning to fail the moment that are installed. 

When it comes to polling those of that have been at this for a very long time, and have a lot of experience and understanding of the success and failures in the game, I think I would be able to gather a pretty solid consensus on the following methods, if asked to decide what your next house would be. 

SIPS. Absolutely, if limited to above grade use.

ICFs Possibly, with a lot of limitations, and the understanding that most cheerleaders for the concept oversell the benefits, and deny the reality of failures in the field. Definitely not below grade.

EIFS Probably not. In desert climates, and over masonry, maybe. As typically done at the residential quality level, over frame construction, never.


As for your comment on insect infestation, Termites and carpenter ants are more than enough of a problem, claiming that they are the only two and not really all that significant, misses the mark. They can and will do major damage to any accessible foam, and can do so without being noticed for years, until the damage is extreme.

Your take on issues below grade is dead on. Another factor is that the typical "stucco" layer used to protect the below grade portion is not only fairly delicate, but totally uninspectable forever. I have seen egress area wells that were forced through this layer by ground pressure and frost, causing significant damage to the structure. I have also seen cases where shifting sharp material in the backfill compromised this layer. 

Bottom line is that foam is a great insulator that performs best and creates the least number of potential issues when it's concealed deeply inside the wall cavities of a structure. Move it outside as sheathing, it creates additional potential problems. Cover it with a synthetic stucco skin, and the problems mount. Use it as a structural foundation, and you keep on adding to the risks.


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## gobug (Dec 10, 2003)

Wharton,

Thanks for pointing out that what I wrote could be misinterpreted.

You wrote "As for your comment on insect infestation, Termites and carpenter ants are more than enough of a problem, claiming that they are the only two and not really all that significant, misses the mark. They can and will do major damage to any accessible foam, and can do so without being noticed for years, until the damage is extreme."

I meant that I only encountered those 2 pests that were a risk to foam in my years of pest control in CO. I did NOT mean they were an insignificant risk. Termites (many varieties) and carpenter ants can do significant damage to the wood in a structure, they just use the foam for harborage or pathways. If the foam is the structural element, they can also do significant damage to that.

There are manufacturers of foam products for construction that add a small bit of boric acid in the forming. This does reduce risk. It will eliminate most of the risk. 

Termites only need a crack about of a 64th inch to enter. While they do not eat the foam, the damage to structure can be bad. Due to lawsuits in the SE US, use of EIFS requires professionals trained and licensed by the mfg to get the permits, inspections and passing grades. Then, in case of product failure, they can sue the mfg. or installer.

This does represent risk for DIY types.

I did repair on a nice SW style house with and EIFS exterior. It had ~300 woodpecker holes. If too thin, and a woodpecker can go through it, the risk of termite or ant encroachment is to the entire surface area of the structure. On one woodpecker repair, the hole was only about doorknob size and the bird removed 5 gallons of insulation to makes it's nest.

Another thing about the EIFS is that it will suck up moisture through capillary action and create another pest problem: mold and fungi. That is why it is not recommended for the inside of a basement wall. In my county I must have 4" of blue or pink foam on the outside of the below grade basement wall.


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## wharton (Oct 9, 2011)

Gobug, thanks for a really informative post. 

I recall when EIFS first became the "must have" on all the McMansions sprouting in the 90s. Shortly after that, trade magazines started featuring spectacular failures involving EIFS over stick frame construction. IIRC, it was possible for a home, located in the southeast, to be severely damaged, and in need of an entire removal of the EIFS, structural repair, mold mitigation, and residing in less that 18 months of exposure. Since then I have seen countless issues, and in many regions it's still being applied as a "low bid, low skill" disaster. 

I have a buddy who walked away from a lucrative contract to renovate hotel rooms. The front wall of each unit was decaying. The EIFS was fairly new, and limited to a few dozen sq. ft. of the front wall of each unit. When he pulled the sheetrock off the interior the wall cavity was a multi-colored, three dimensional mold and fungus scene that was almost unreal. After a bit of research, he doubted his ability to protect his crew from all the potential health issues, and decided to pass on the work. The work was being done in phases, and the rooms were heavily rented, with the management's full knowledge of what the conditions were in rooms awaiting repair. 

The woodpecker info. is interesting. When it first became popular in institutional and commercial work, architects fell in love with it. It was pretty comical to be at a dryvit wrapped school, and see the damage at every wall surface where the kids would hang out. Once the little buggers figured out that it was pretty easy to lean up against the wall and kick your heal through the junk, it was game on.


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