Questions About Building a Maine Yurt

[Yurtsteaders]

Hey All! I've been perusing this forum for the past few days. Lots of great stuff on here!

A little about us. We purchased some acreage in central Maine a few years ago and want to start homesteading. The price of lumber foiled our plans to build a small cabin so we started looking into a yurt. We found

Blue Ridge Yurts

in VA and were excited that they made yurts with 10ft walls. We definitely want to have a loft for sleeping to maximize yurt space. We have a 30ft yurt on order from them for this May.


We are going to make just a circular platform because after pricing out Blue Ridge Yurt's engineering plans for a deck, we discovered that it would cost us over $8000 in mostly lumber. Yikes. So I have been eyeing some plans for just the circular platform from other manufacturers. We have limited construction experience but a lot of determination. Does anyone have any

yurt platform

plans they recommend or would like to share? I'm also wondering how many footers are appropriate for a 30ft platform?

Has anyone had any experience with using these in building a

yurt platform

? https://titanbp.com/pages/deck-foot-anchor/

I emailed the sales rep and he said they would work for yurt construction. The prospect of not having to dig 4+ feet down and pouring 90 something bags of concrete is very appealing.

My next question is: We had ordered the yurt with the Reflectix

insulation

. Is that worth the extra money? Is there something better we can use?

We already purchased a Pioneer Maid wood cook stove which is rated to heat 2,200sqft. I think that will be sufficient for

heating

but I don't want to have to constantly be tending to the stove.

We are planning to insulate the floor with Roxul and possibly foam board if we can find some for cheap.

We'll have more questions for sure, but for now I'd like to cover the basics.

Thanks,
Yurtsteaders!

[Bob Rowlands]

If you have a flat lot pour a slab. Since it is sitting on the ground you won't have issues with it getting engineered, it won't be considered permanent if it sits on the ground. At least that's here in CO.

If it is a sloped lot, then the foundation and platform plans on a couple commercial manufacturers internet sites can be acquired. I have looked at those and the structural engineering is very good.

I don't know anything about the screw anchors. My guess is, getting them accurately placed,(necessary for post and beam decking), has the potential to be a real trip if there are big stones in the ground that drive them out of plumb and off your string line. If they can easily be drilled into the ground, then cool.

If you end up wanting to place concrete piers, spend the money and order concrete from a batch plant. Have forms, anchors, lines, tools, rebar cut to length everything 100% ready to go and the pour will go very fast. The driver will gladly guide you through the process. Make SURE you have gloves and muck boots, and working hands or other skin balm.

Yup, a wood deck is gonna cost you serious dinero nowadays. That's just the way it is, you have to figure how to deal with that. Maine is fully treed there might be local sawyers that can get you a better price than the lumberyard. Beats me. Ask around. If you have a carpenter friend get advice from him. At any rate good luck.

[skihuckster]

It's not surprising that your deck materials are expensive. For my 30' yurt the materials for the deck were on the order of $28k and that was OPTIMIZED and engineered taking advantage of local materials. If I had purchased what the deck guides suggest, add $10k. So I'm thinking: red flag!!

A 30' yurt is a lot of area: 706 ft2. For a deck with lawn chairs, code says the structure must support 40 lb/ft2 with a specified maximum deflection of supports. You may not be subject to code but the number can be translated as "you shouldn't have problems with normal use if you follow this". If you go less all manner of issues may haunt you through the years. But that's just a deck for entertaining at a BBQ. For a yurt you need to consider the weight of the yurt, furniture, occupants, snow, ice, and wind. If the yurt is in Hawaii, I wouldn't design the deck with less than 50 lb/ft2 rating. For regions with winds up to the 50s to 80s and accumulating snow up to 2 1/2ft I wouldn't have less than 100 lb/ft2. For more snow, just keep adding. So Maine, I would expect snow, say 100 lb/ft2, your deck needs to withstand 70,600lb atop it, or 35 tons. All that weight is transmitted through the floor to the joists to the posts to the footers.

So how many footers do you need? depends how you build them! I did 16 beefy ones, concrete below frost line, so each one is taking 4400lb except the ones in the middle actually take more and that's actually a hypothetical load ON TOP of the weight of the deck, yurt, people, snow...I'm guessing the unoccupied dry weight is on the order of 8-10 tons.

The Titan footers you reference seem to suggest a max of 1800 lb on each. So lets say a skimpy 5 tons of building material and 35 tons load = 40 tons, you'd need 45 of those supports MINIMUM. But even then they float above the frost line and your deck is going to get majorly upset over a few winters.

If you're planning on living in this for many years, you're going to spend a lot less in the long run putting in proper concrete footers. Concrete is cheap and if you price it out you'll probably see that you can get a truck out for less than the cost of the bags (never mind the trouble of hauling the bags and mixing them!)

Insulation

. I think the yurt manufacturers have done a good job picking out compatible materials that work for yurts and the biggest challenge is installing it, but if you do it during pitch it's a cinch. It's probably worth it, and chances are you won't do better for less money. I feel like I've learned that lesson over and over and I keep tricking myself into thinking I can cut costs. They always come in some other form. If your manufacturer will cut the insulation to size, you'll thank yourself when you pitch.

Stove. The rating for ft2 for a stove takes in a lot of assumptions, most of which probably don't apply to your yurt. There's lots of good web calculators out there and I like this one for whatever reason: https://www.glowing-embers.co.uk/blo...ut-calculator/

It will depend on how well you insulate your floor, if you insulate your roof, how cold it will get outside and how warm you want to be inside on that day. But it's important to get right. Too small and you'll never get warm. Too large and you'll be opening and closing windows all winter. But most important is to get something with a lot of thermal mass (soapstone if you're feeling saucy) that will keep more of the heat from your fire and radiate it out slowly. Thin cheap stoves don't buffer the heat from the combustion and you lose a lot of heat out the flue while burning through cords of wood and sweating your socks off. The really fancy models can heat a room for a day on just a couple pieces of wood but they cost as much as a yurt and would look stupid in one. Sounds like you have your stove...consider how you can line it with bricks and build a nice hearth that soaks up heat.

Floor. I highly recommend you look into SIPs. They cost more, but not much more. When I costed out my raised round part of the deck, I came up with an estimate of about $5k in materials that included insulation to give me R15 insulating value. And it would have been a HUGE job to build it. I bought a SIP deck instead which cost me $9k delivered, is R28, is perfectly circular, and I snapped it together in an afternoon with my 8 year old. The $4k extra was worth it to me, especially after experiencing how much work it was to build the much simpler support structure for it.

Plans: CO Yurt Company has deck plans for 30' yurts on their site and that's a good place to start.

Bottom line: you're going to get what you pay for with your deck. But then again, maybe you'll get more when you pay more. Would you rather spend $20k to build right the first time? Or $8k to build it wrong and three $5k installments to fix future problems?

I hope that helps. I love this kind of thing so keep questions coming!

[skihuckster]

Originally Posted by Bob Rowlands

If you have a flat lot pour a slab. Since it is sitting on the ground you won't have issues with it getting engineered, it won't be considered permanent if it sits on the ground. At least that's here in CO.

If it is a sloped lot, then the foundation and platform plans on a couple commercial manufacturers internet sites can be acquired. I have looked at those and the structural engineering is very good.

I don't know anything about the screw anchors. My guess is, getting them accurately placed,(necessary for post and beam decking), has the potential to be a real trip if there are big stones in the ground that drive them out of plumb and off your string line. If they can easily be drilled into the ground, then cool.

If you end up wanting to place concrete piers, spend the money and order concrete from a batch plant. Have forms, anchors, lines, tools, rebar cut to length everything 100% ready to go and the pour will go very fast. The driver will gladly guide you through the process. Make SURE you have gloves and muck boots, and working hands or other skin balm.

Yup, a wood deck is gonna cost you serious dinero nowadays. That's just the way it is, you have to figure how to deal with that. Maine is fully treed there might be local sawyers that can get you a better price than the lumberyard. Beats me. Ask around. If you have a carpenter friend get advice from him. At any rate good luck.

Everything Bob said. He reminded me that I saved at least $10k by getting timbers cut from a local sawmill. Just make sure you put some wood treatment on something like that to keep it from rotting. And screw anchors with stones...best laid plans can be ruined by some inconveniently shallow bedrock. If Maine is anything like NH I'd be going into the foundation work with trepidation!

[Bob Rowlands]

Since you mentioned wood treatment, back in the 70s and early 80s we would have squirted 'penta' anti bio chemical over the sawmilled platform framing. KILL 'EM ALL!!! was how we rolled back then. lol

[Yurtsteaders]

Skihuckster,

What's your definition of 'beefy footers.' 12in or bigger than that?

Where did you get your SIPs panels?

Thank you both for chiming in here. Very helpful.

[Ivan]

hi,
i looked at the titan anchoring system, seems that they would be good in preventing your Yurt from blowing away, but they would still heave with frost? Which is okay as long as you can re-shim your support beams every couple of years. We have a Yurt on Cardigan mountain in New Hampshire, our soil is filled with granite boulders ranging from football size to house size, so that anchoring system would not work in our terrrain . It took us 8 days of jackhammering our 20 some footings, so i know what you are saying. We did not use concrete , just put crushed stone in the bottom and buried 4x4 or 6x6 pt posts . They have not moved and are in good shape after 6 years. The depth range from 12” to 4’ based on the rocks or ledge. We used the Pacific Yurt platform plans, as the beams are 4’ between each other, which will support 5/4 T&G, which is pretty readily available and easy for my wife and I to install. although we put the foam insulation board between the beams before we put the decking down, so we would have to crawl on our backs.. some folks will sand the floor and seal before the Yurt goes up, as it is a pretty floor. I bought a used Dutch west ( $500) which is rated for 35,000 btu, and feel that i could have gone another size bigger, as it needs to be tended every 3-4 hours when temps are around 0F , but will keep the place at a comfortable 70F. We had to haul everything up a trail maybe 300 yards from a unmaintained logging road , so that also was part of the decision making. Along with the fact that i am extremely cheap . I think all of the ideas posted to you are great, and you get to sort through them and pick what is more suited for you. If you need a hand one day, let me know,Maine is not that far from NH.

[skihuckster]

Originally Posted by Yurtsteaders

Skihuckster,

What's your definition of 'beefy footers.' 12in or bigger than that?

Where did you get your SIPs panels?

Thank you both for chiming in here. Very helpful.

I used Bigfoots, which expand from a sonatube to a larger diameter and look kind of like a bell. The ones in the middle of the deck (x4) are 12" sonatube and the bigfoot expands to 28". The ones around the outside (x12) are 10" sonatube and the bigfoot expands to 24". That worked out the equivalent of 117 80# bags concrete. I used Simpson anchors that I set with the pour as they hold better in wind, but are otherwise a lot harder to install than drill in post anchors. I'm pretty sure a structural engineer would have made me use 16 or 20" diameter sonatubes but the 10s and 12s have more than enough compressive strength and I took advantage of my county not requiring engineers drawings.

I'm near the top of a hill and my groundwork was a nightmare. The deepest I could get with a jackhammer and rock bar was 36" below grade, the worst was 10". For some shallow ones I actually didn't even use a bigfoot and drilled some holes in the bedrock and epoxied in some rebar and put a sonatube around that. Compared to the cost of lumber for my deck, the footers were basically free. But lots and lots of back breaking digging!

I'm out west so I got my SIPs from ICS in Ft. Collins, CO. SIPs were invented and had their first uses in NE (I think) and I'm sure you have some quality options in VT and maybe NH. ICS has a sister company in NC but I forgot the name. For a yurt floor, the shipping cost may dominate so going local is probably your lowest-cost option.

I'll try to post some pics in the next few days. That might help.

[Bob Rowlands]

Good info. Thanks.

[skihuckster]

Figuring out adding pictures so bear with me...

8699 shows the sonatube and bigfoot together. The tube screws to the bigfoot and the bigfoot sits in the bottom of your hole. This will get filled with concrete and become a monolithic footer that transmits the weight of your structure to the earth and distributed it across the surface area of the BOTTOM of the bigfoot. The bottom should be below frost line or on bedrock, whichever is shallower. the tube needs to come at least to grade. I cut mine to be 1' above grade so water isn't sitting against my posts.

8704 shows the backfilled form. You simply fine-position (using masons line and Pythagorean theorem) and plumb the tube and backfill around the bigfoot and tube. At that point it's solid and ready for concrete. Notice the rebar. When you fill these you pour in your concrete, pop bubbles with a rock bar or vibrator, and just push your rebar into the concrete before smoothing the top. Fast and simple.

8712 shows an example of when you can't get your hole very deep and need support for your tube (this picture, the tube doesn't even have a bigfoot, it is instead "pinned" into a giant rock). I attached scabs to the tube with wood screws from the inside and then screwed support 2x4s to the tube and then the other side to a grade stake to keep the form from moving when I slosh heavy concrete into it.

8770 shows my footers freshly poured. I used post anchors that are set into the concrete which required some careful placement. I wish I had taken a picture of the jig I used, but essentially I snapped chalk lines across my footers, went over them with sharpie, and made sure my anchors were centered between the sharpie marks.

8774 shows what the SIPs look like pre-installation. Mine were 4' wide as up to 10' long. The heaviest was about 150#...easy for two people to move and position.

All this said if I did it again I would have dug my holes bigger than necessary...I wasted so much time taking 4" off the side of a hole to move a form over and into line, I didn't originally dig bigger to "save" effort (I didn't), and backfilling was the easy part. I also would have rented a concrete vibrator. I popped bubbles with a rock bar but a few of the piers were imperfect above grade when I peeled back the forms.