Hi!

We are putting up a wooden sided yurt from Smiling Woods Yurts near Lyle, WA in the spring and I am trying to figure out how to handle interior insulation and walls. I LOVE the cob look and the ability to add nooks and benches as well as building up a cob structure around our wood stove. We don't want to use any plywood or sheet rock for the walls and I am only considering the *greener* alternatives for insulation (wool, denim, cellulose, and maybe airkrete). So my question is can I put up insulation right the wooden walls and then just do cob right over it? I imagine just doing only cob won't give me a high enough R value for code. I really want the inside to be cob so am willing to do whatever needs to be done to make that happen!

Here is a description of the walls from the smiling woods website : The walls are framed with 2x6 lumber.
The framed walls are sheathed with a 1/2" shear panel, then covered with a vapor barrier and sided with 1x6 tongue and groove western red cedar siding.

Hello B. Max.

Welcome to Permies, if you could, please finish filling out your profile page with descriptions, location, and a brief history. It really helps folks understand where you are at and what your about.

Now I will try to address your questions, but first must acknowledge my bias when companies like, "Smiling Woods Yurts," start marketing a product like theirs. I don't like when folks try to move into the "natural, sustainable, traditional" building market by "white washing" a main stream product that has heavily industrialized product materials at its core and then gives itself a name to attract the "consumer public" that maybe looking for a actual "green and sustainable" building system and aren't getting that at all. These are not Yurts, and the only think they have in common with a yurt is they are round. If you take that away from them, they aren't much different than the prefab kits you can buy at home depot or other box store, or general contractor. Sorry for that, but I have to confront it whenever I see it, and only part of this is my subjective opinion, the rest is simple fact.

Now for your questions:

We are putting up a wooden sided yurt from Smiling Woods Yurts near Lyle, WA in the spring and I am trying to figure out how to handle interior insulation and walls.

I would not recommend going with them, but designing (or have designed) something specifically to your wants and needs as well as the land it will occupy. I am not a fan of "cookie cutter architecture." (that is subjective on my part after 35 years + of doing this)

I LOVE the cob look and the ability to add nooks and benches as well as building up a cob structure around our wood stove. We don't want to use any plywood or sheet rock for the walls and I am only considering the *greener* alternatives for insulation (wool, denim, cellulose, and maybe airkrete).

You can, and I commend you for you desire to stay as green as possible. You can do much better than store bought materials for that. I would also warn you at this time, that though cob is enchanting and wonderful material, there is way too much romanticizing this and other building modalities. Do it because it makes sense, is environmentally, ergonomically, and financially sustainable and practical for you, not just because you like it.

So my question is can I put up insulation right the wooden walls and then just do cob right over it?

Yes, and/or a system like that. I would in your case perhaps consider a straw bail, if the straw is attainable within 25 miles radius of the building site. If not, them my next choice in your case with be a slip form wall of "straw clay," cobbled from the inside, and perhaps either cob, (more work) or a rain screen wall and wood siding. It all depends of final location, the land it sits on, the topography, etc. Of course my frame structure would be timber frame, but that is my bias and craft as a Timberwright, (and no it is not more expensive than the system you are considering.) The national average for simple timber frames is between $25 and $35 per square foot for a frame kit, sometime even less expensive depending on resources, owner/builder assistance, and related aids to bring the price down.

I imagine just doing only cob won't give me a high enough R value for code. I really want the inside to be cob so am willing to do whatever needs to be done to make that happen!

No it probably will not be practical to achieve Code R factors with cob alone as the walls would be overly thick. In some cases this is not a bad thing to have nor impractical, but in most cases it is, due to the budget and material resources.

Here is a description of the walls from the smiling woods website : The walls are framed with 2x6 lumber.
The framed walls are sheathed with a 1/2" shear panel, then covered with a vapor barrier and sided with 1x6 tongue and groove western red cedar siding.

Yes I can see that, and you could do that all yourself, with the help of a local contractor if you do not have the skill sets and a local saw mill, which would be my recommendation if you really wanted something that looked like the product you shared.

Regards,

j

Thanks for your info Jay! I will fill out my profile better next time I get the chance for sure. Hmmm, that is disheartening to know that you feel so negatively toward smiling woods. We have already sent a deposit so there is no going back for us now. We were originally planning a vinyl sided yurt (do you feel the same way about those?) but we were steered away from those as our wind and snow load and a friend who has built one out our way said they would have gone with a hard sided yurt if they could have. We need a kit as my husband will be doing most of the work on his own and right now we are living in one bedroom (literally in a bedroom at a friends house) with our two year old son, so getting something up quick was a priority. I was under the impression they used FCS certified wood that was Pacific NW grown and besides that I didn't really think of them as being any more than a wood cabin kit, just round. They are located just north of us in Washington so I consider it a local purchase as well. It may be a prefab but it fits our land and what we are looking for very well for what it is intended to be for us. Getting a livable structure up quickly will enable us to take our time when we build other structures as well as focus our attention on improving our land and getting our forest garden going. But with all that said it might not have been the best choice but it was the one that we felt was best at the time and so we will just have to follow through and learn through our mistakes. We have never attempted anything like this before so I'm sure it won't be the first or last mistake we make but I am very sure that we can still make a happy home out of whatever comes!

Thanks again for your answers!

Hi Manijeh, I was just wondering how your smiling wood yurt with cob worked out? Any pics to share?