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Rock Knocker
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# Posted: 14 Feb 2018 16:34
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Hello, I just found this site and I've got a whole list of questions about building a cabin.
I plan on building a cordwood house, I don't have plans written up yet but I would like something with right around 800sq.ft. main floor and then a loft for a main bedroom with a guest bedroom and bathroom under the loft.
My biggest questions are about wood prep and building this house to be able to hook up to electric and septic in the future. I plan on using Poplar wood for the cordwood and mostly maple for any posts and beams I may need to build a loft or other structural purposes.
I was wondering how long the wood should be dried for before starting the project or if there are any ways to speed up the drying process.
I would like the house to have a water hook up from a well and down the road worry about septic and electric but in the building process I would like to do all I can to make the septic and electric hook up as smooth as possible.
Right now I have so many questions I can hardly keep them all straight, so any advise on house/cabin building will be welcome.
I am also certainly no house designer, I have ideas in my head but getting them safely into a cabin is something else, if anyone knows if I can find small cabin designs to look up that would be great too.
And thanks for letting me on the forum, I look forward to learning a bit about building my own cabin. Thanks!
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rockies
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# Posted: 14 Feb 2018 19:01 - Edited by: rockies
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A cordwood cabin will require an awful lot of tree lengths to build, and that equals a lot of weight. What type of foundation are you planning on using?
Also, bear in mind that it will take about a year for all that wood to dry, then you will have to pick through the piles and find the best logs (all this wood will have to be covered from the weather during the drying process). After the cabin is built the logs will continue to shrink a bit when the interior heating system is activated.
If you have never done this type of construction method before I would recommend trying it out on a shed first. It will then be possible for you to decide if you want to proceed with cordwood for the main building rather than getting 1/2 way into the project and running out of steam.
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Rock Knocker
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# Posted: 14 Feb 2018 20:27
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I am planing on pouring a concrete slap with floor heating for future use, how thick of concrete I'm not sure yet but I plan on over doing the structural integrity of everything.
I've got 2 cords of poplar set aside already and I've got a conservative estimate of 6 cords to cut in my back yard and two more in a friends yard, and I should find some more once I start looking around. There are also a whole lot of plantation pines in the area, what I can't find in poplar will be filled in with pine. I'm hoping not to need much more than 22 cords total for the cordwood. The maple will be a different story but the poplar and pines are pretty much given away in this area.
I was also thinking about making a smaller shed, it would be a bummer to use up the resources.
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rockies
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# Posted: 15 Feb 2018 20:01 - Edited by: rockies
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Cordwood is tricky. Usually a wall ends up being 18-24 inches thick (which makes placing windows and doors tricky) and that creates a lot of weight. A slab foundation can be 4" thick but must be thickened under the exterior walls and any interior posts.
Then there's the grout. Sometimes it's too "hard" so the grout remains rigid and inflexible while the wood continues to shrink and move.
What most people don't know about drying their own wood is that the logs will only dry to a moisture level that is equal to the moisture level of the surrounding air (usually anywhere from 16-21% moisture content depending on your location in the country). Once you start using the wood for a building and then add an artificial heat source the wood continues to dry to about an 8-10% moisture content. If the grout is "hard" the cordwood can pull away from the grout as the wood shrinks and that causes tons of little cracks to open up in the wall for moisture to seep through.
Also, the moisture content of the exterior end of the log can be much higher that the interior end (due to rain soaking the exterior end) and the end grain of the log will also wick the water further into the wall. To minimize the amount of water hitting the walls you'll have to build a roof with very wide overhangs all around the building or preferably build yourself a wrap around porch.
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Rock Knocker
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# Posted: 15 Feb 2018 23:11 - Edited by: Rock Knocker
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It makes sense that the wood would lose moisture then shrink and pull away from the grout but if I do build with wood that has been kiln dried to a low moisture level would I have to worry about the wood ever expanding with enough force to damage the grout, sort of like water in a pipe?
I was also planning on pouring the concrete slab with pipes in it for floor heating. I was wondering if I would end up with the same low humidity levels in the winter, I've been to some buildings with floor heating that stay very humid in winter but they were also driving trucks in and out and getting snow on the floor. I'm not sure the same would apply for me unless I throw snow around my house periodically.
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jtamlin
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# Posted: 16 Feb 2018 10:03
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I agree with rockies, try something small first. I have a friend who did exactly that, built the shed/outhouse first from cordwood. It turned out really nice BUT was enough that he decided to build his cabin differently, which incidentally also turned out very nice. It was way more work then he thought, and he had lots of problems with the grout/chinking and the expanding and contracting of the wood. This was in northern Saskatchewan where temperature and weather can be extreme, maybe it would work better in a more stable/arid climate. Good luck whatever your decision is, and post some pictures!
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rockies
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# Posted: 16 Feb 2018 19:29
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The price for kiln drying enough wood for an entire cabin would be extremely high. The big problem with logs is that they tend to crack across the end cut as they dry, which is exactly where the water will wick in from the exterior.
Personally, I'm not a big fan of cordwood because there isn't really a way to insulate the walls other than building a separate stud framed interior wall (and then you hide all the exposed interior log ends which defeats the look of having a cordwood cabin). In effect, the cordwood wall becomes your structure, vapor barrier and insulation all in one and while it may be a sound choice for structure I don't think it does a good enough job as a vapor barrier or as insulation.
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ICC
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# Posted: 16 Feb 2018 20:00
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Radiant floor heat can be very nice in a full time residence. It's relatively easy to lay the piping when using PEX. I have done two floors, different levels in same building, using PEX. I've only activated one in the more used area. Very nice having warm floors. If doing that with a concrete slab like I did be sure to use a good layer of foam under the slab. Thickness dependent on climate.
Are you planning on using the cordwood walls as structural components or building a timber frame and using cordwood as infill?
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Rock Knocker
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# Posted: 17 Feb 2018 13:26
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Floor heating definitely seems like the way to go especially starting a build from scratch and plan on an outdoor boiler from the start. I've laid PEX before pouring one floor before and it's pretty darn simple. I'm most curious about winter humidity with floor heating vs warm air blowing around.
And while it may be a small factor over all, I do all my own cooking each meal which generates a decent supply of humidity in my larger house now, so I am slightly optimistic with floor heating and regular indoor cooking to keep a small cabin slightly more humid than a furnace heating system and microwaving TV dinners.
As for the framing plans I am still working on that. I am in between using cordwood for the structure and whole maple logs for structure only for a second floor loft or using maple logs as a post and beam structure then filling in with cordwood.
I've been looking into cordwood as much as possible lately and asking around another forum besides this one. I've heard a decent amount of cons, but I think I can deal with the problems brought up. Just going through this process vs paying my current mortgage is going to free up a lot of time and money. I would rather put time and effort directly into my house than put time and effort paying bank interest.
I am thinking of pouring a concrete foundation with a 1 foot raised lip around the outside so I can bring dirt in to raise the grade away from the house as much as possible and I'm looking into these living grass roofs that would catch a lot of rain water. I'm planning on a front 3 seasons porch and I should be able to make a large overhanging roof to keeps water further away from the walls.
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Steve_S
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# Posted: 17 Feb 2018 14:24 - Edited by: Steve_S
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Couple of points to ponder. We were very seriously considering Cordwood and ultimately decided against it for many reasons but the biggest being time & labour. Do your research, get to this site and buy Richards Book and look at the affiliates.
http://www.cordwoodconstruction.org/ Take a course if you can and build a small building first.
Wood: We have a LOT of cordwood homes, barns and more around here, some standing over 100 years and still in use and perfect condition. (those built with cedar). As a result I got involved with a local builder who does these, learned much and realized the labour involved. Many woods are NOT suitable, poplar being one of them. For cedar you cut, debark, size it to size your building with and split and stack open to air dry 2 years from fresh cut. *cedar is bug & mildew / mould resistant.
Corners & Structure can vary and many options are possible, Oak / Maple Post & Beam with infill to interlocked block corners (I like the interlocked corners much better) which are stronger and look nicer to me anyways.
Various styles of corners shown here:
https://www.google.ca/search?q=cordwood+corners+detail&source=lnms&tbm=isch&sa=X&ved= 0ahUKEwj51bj0zq3ZAhXq6oMKHU0wAEUQ_AUICigB&biw=1274&bih=924#imgrc=_
Typical wall thickness is min 18" to 24" and with Cedar that's R5 per inch, lower with other woods.
Do NOT use cement mortar, you need a breathable mortar, preferably lime, it will give with expansion & contraction and not fail while allowing moisture to get out, cracking & shrinkage will occur and needs maintenance but it settles.
Concrete Slab has to be serious, for our's the recommendation was a perimeter of 24" x 12" deep (planed to use 20" log) and 5" overall reinforced slab. Option was to use Fibre Reinforced (better) or Rebar reinforced (potential issues with rebar sweat and cement cracking). Regardless of where you are, if your using Radiant Heat in a slab, you need to insulate the slab to the exterior to prevent parasitic heat loss through it and you need that 6 mil sealed vapour barrier between insulation & slab to prevent moisture creep. FPSF Slab is really the only way to go and "NO SAND UNDER IT !" only good hard packed base.
We did use Radiant Floor Heating, full kit for our build was purchased from https://www.radiantcompany.com/ including the Takagi Heater. ** Absolutely love it and no moisture issues or concerns whatsoever. As the system is only Radiant Heat, we filled it with "Hercules® Cryo-Tek™ - 100" propylene glycol (enviro safe). REF: https://www.oatey.com/2377209/Product/Hercules-Cryo-Tek-100
Deep eves are a must and you really have to consider back splash from rain etc onto the wood & mortar. A Wrap Around porch is a great way to solve that BTW if inclined. Other methods are possible though.
** Radiant System I would also note, that I am simply a happy Radiant Company customer, their product quality is top notch, excellent & fast support, very well priced (especially the heating systems themselves) and they provide the designs and specs and optimal setup for it. OF NOTE: My propane installer has been installing Radiant Systems of his own for 15 years, when he saw the Radiant Co's system he became very curious, they use thermostatic balancing in their design which improves efficiency of heat & on the heater cutting energy required (read as fuel saving). He took photo's and made a comment "shit, wish I had seen this before, this will solve several issues I've had with my systems and cut running costs too". !!! Use a Floor Sensor in your slab NOT an air thermostat for determining temps, air gives false readings of temp when cooking, woodstove used etc.. keeping radiant from kicking on, the slab is what to gauge for correct temp & operation.
Lastly, do look at Richards and others sites, do buy a book or two, cheap enough from Amazon (and much cheaper than learning the hard way) and watch their videos and presentations. Maybe you can go help someone building a cordwood house for a week and get a feel for it... OR if your lucky to have a cordwood builder nearby who is friendly (luckily we do) they will help you learn more and maybe let ya help, they always like free labour who does not cause more labour. I have an extensive library on it all but keeping it for posterity. We decided to go Stick Framed and a different route because of our situation (mine mostly, my health is failing fast and time is limited for me to do what I want to get done).
PS: "I am thinking of pouring a concrete foundation with a 1 foot raised lip around the outside " You may want to have a look at Slip-forming with local Stone and that would provide backsplash protection and look nice (more natural to the type of build).
Hope that helps, good luck.
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Rock Knocker
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# Posted: 17 Feb 2018 15:58
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Excellent write up Steve, thanks a lot. I will take some time looking over everything you provided.
A couple of the main reasons I am choosing to use cordwood is because of how much time I will have once I sell my mortgage and at 32 years old I am in as good of shape as I ever have been, plus I have friends and family interested in helping.
I'm a self employed farrier but I work some part time jobs to cover all the bills. Once I sell my house I can make a very livable wage on 10 hours of horse work a week, the rest of my time will be put into my house.
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rockies
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# Posted: 17 Feb 2018 18:23 - Edited by: rockies
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If you're going to pour a slab with radiant heating have a look at this product.
http://www.legalett.ca/frost-protected-shallow-foundations-geo-slab-icf-floors-passiv e-house-passivhaus-net-zero-energy-building-leed-concrete-slab-on-grade-air-heated-ra diant-systems.html
What are you cooking with? Bear in mind that if you are using propane for the stove it can add a lot of humidity to the interior of a home too.
I don't know how well cordwood would endure supporting a second story loft. You might consider building a timber frame inside the cordwood wall and supporting the loft like that so the loft doesn't actually touch the cordwood walls).
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silverwaterlady
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# Posted: 18 Feb 2018 14:08
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https://baileylineroad.com/build-a-house/
I don't know these folks personally. I've heard about them around the island. The weather on Manitouln is cold and snowy like MN.
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Steve_S
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# Posted: 23 Feb 2018 09:44
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Two and even 3 storey cordwood / stackwall homes are not that uncommon and stand up quite well. A simple peek at Google Images on Cordwood homes and you'll see that 3/4 of cordwood homes are more than a single floor.
Of course it's all relevant to locality and building code requirements, for example in California were earthquake prevention codes will necessitate additional supports & tie in's, bracing etc would not be required in an area which does not suffer quakes. Same if your building a home in Oklahoma where twister threats must be taken into account and where building codes reflect such requirements.
See what the requirements and codes are for your area in particular and locate "local experience" if & whenever possible. This is simply not a project that you will decide on Monday that you want to do and start chainsawing tomorrow and swinging hammers by Friday. It requires a lot of thought, planning and serious consideration as to what & how to best accomplish it in your particular area / region and climate zone. And YES, Climate Zone + Region do factor into it and never forget that as it affects what materials to use, where & how and how to address regional / local issues, think types of bugs & critters, humidity & moisture exposure and much more.
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rockies
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# Posted: 23 Feb 2018 20:02
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A nice site about people building a cordwood house.
https://accidentalhippies.com/
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rockies
Member
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# Posted: 24 Feb 2018 18:47
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List of books available on cordwood and other types of unique construction methods. Have a look at "Cordwood and the Code" in particular.
http://cordwoodmasonry.com/books-media/
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deercula
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# Posted: 24 Feb 2018 22:05
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https://www.youtube.com/watch?v=zsoh0Y_VXdY&t=25s
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Rock Knocker
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# Posted: 25 Feb 2018 18:27 - Edited by: Rock Knocker
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Thanks. Some useful stuff there.
Things are slowly moving along. Getting house ready to sell and trying to think of anything I haven't thought of.
I found a good deal on 15 cords of dried cedar for the cordwood, for a 25'x35' floor that should be just about what I need and I should already be set with maple for posts and beams.
We got around a foot of snow up here this week so I've got some time to kill.
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