traditional yurt corkscrewing prevention

[warmwoolenmittens]

hey y'all,

my husband and i setup and moved into a sweet 5 wall mongolian yurt 4 months ago. we're in the pacific northwest. i've been noticing slowly over time that i think our

center ring

is corkscrewing a little bit- the roof poles don't line up square with the crown. i've gotten my sweetie to help me trying to sort of unscrew the roof with by scootching the 2 support poles, but it ends up with the center poles being a bit skewed- sitting unsquare with the crown that doesn't spin with the attached poles.

so i'm not quite sure what to do- first to unscrew the crown to get it more square (all this square talk, the irony is not lost on me), and second to keep it from twisting in the first place.

my various searches have been relatively fruitless. any suggestions?

pi

[stephanwik]

During a Force 10 storm last winter we noticed the

dome

starting to rotate, and one of the rafters fell out.

We attached four steel cables to eyelets on the crown, installed 2 x 4 rafter supports, threaded the cables down the rafters and walls and then cinched them down with bottle screws. No problems since then.

[Jafo]

On the

Pacific Yurts

, they have cabling that goes through all the rafters. You can see the first row of them in an old pic of my yurt:



Other companies will use wood blocking between the rafters to accomplish the same thing.

[warmwoolenmittens]

our yurt has about 80 1.25x1.25 inch poles for rafters and the spacing between them is not consistent. in my whimsical mind, i could perhaps get ahold of a bunch of similarly wide bamboo and scoop out notches and wedge them in with lashing in whatever spots they fit...

i think the 2x4 idea would not suit very well for this yurt. i can't quite imagine it. there are two ropes that go out from the crown and tie down on the walls on opposite ends- i periodically tighten them, but i'm not sure if they quite hold the crown still enough to stop the twisting. it's such a tension game!

appreciating the responses! it's getting my mind jogging on solutions~ thanks

[Jafo]

Is this a custom made yurt? It looks a lot like a groovy yurt. Either way, it is definitely the same style. I will ping Yves and if they are not on the road or out of the country, he might give you some advice on these particular types of traditional yurts.

[Bob Rowlands]

Try to realign the rafters perpendicular to the ring using whatever technique you can figure out. Whatever you do, do "NOT" release tension on your tension cable!

A cheap way to halt twisting, or possibly remove existing twist, would be to shim the gap between each rafter and its mortise. Buy a couple bundles of builders shims at Home Depot or Lowe's. Eyeball the gap, trim the shim tip for width and thickness, and hammer the shims up into the mortise either side of the rafter, or just one side, as necessary. That will snug the rafter up real nicely and help stop twisting. I'm assuming you have a very stout roof ring that can take this procedure without damage.

If you can't realign the rafters beforehand, diving shims on the 'tight' side just might help realign them through the wedging action. Good luck.

[Bob Rowlands]

Here's another idea. I don't know what your rafter to ring connection looks like. But, to help ensure your rafters don't pull loose from the ring in a twisting action, you can tie the rafter to the ring with 'Simpson Strong Tie' brand thin gauge strap connectors at Depot or Lowes.

The ones I'm talking about are thin galvanized sheet metal, about 4" or so in length, and have holes in them. They're .50 cents apiece maybe? They are easily bent with pliers. The guys at the store (might) know where to look. If not, usually the framing ties are in the concrete aisle. You'll know you are there because there will be literally a hundred different configurations of ties laying loose in the bins. Plus the connector is stamped Simpson Strong Tie.

Custom bend the tie to overlap from the bottom of the rafter onto the roof ring. Hold in place, bore pilot holes, and run two plated 1.25" screws into the rafter and two into the ring, to secure. Not exactly pretty but would fit your flat bottom rafter very nicely. Installing a tie every other pair should stop any twisting action by sheer redundancy. Houses are loaded with these connectors by code. They work really well.

Just a thought. Good luck.

[warmwoolenmittens]

hey jafo,

from what it looks like i think

groovy yurts

and

suntime yurts

(west coast) import from the same company in mongolia that makes these, so they should be practically the same.

the crown to rafter connection is just a square drilled hole in the crown with the square-pegged end on the rafter. you just pop it in there. on the wall end of the rafter, there's a little loop on the rafter that loops around each crossjoint on the wall.

there are no cables in our yurt, just animal hair ropes. we tied around the wall once before it was covered to keep tension and the outside has 3 ropes over the coverings. the two cental poles are also tied onto the crown with ropes.

so far i'm liking the idea about bracing between the rafters. all the rafters are straight, even if the space between them isn't consistent. i could perhaps draw out a design for my woodworking father-in-law (or just jigsaw it myself) for a kind-of form brace, that could brace between rafters according to the wall section (because it's the variability of the lattice that creates the space discrepancy between rafters). setting it maybe a foot out from the rafter crown connection?



i don't have any carpenter engineering stuff training; if any of you do, please improve on this or advise if you're willing. i usually bring stuff by my father-in-law too to see what he thinks.

again, appreciating the ideas coming in on it~!

pi

[Groovyyurts]

Hi Pi,

No worries, your ger is most probably perfectly fine. There might be a few reasons for the situation and it would be easier for me to have a couple pictures:

1. Has the yurt correctly been set up?
-You should have 81 roof rafters (huns) in a 5-wall yurt. 9x9 nine is a holy number for Mongolians and this is the yurt size they mostly use. Being an uneven number, you need to make sure that the toono (dome) is well positioned (roof rafters evenly spread on the door, on each side of the door's rope).
-There should be 4 ropes going from the toono to the 4 cardinal directions. 1 on the center of the door (south) the other ones N, E, W... well tight they will help prevent the twist
- the end of each huns must be nice and square and fit well in the toono's (dome) square holes (that is an issue of quality, not set-up!) .

2. yurt natural diameter larger than platform:
It can happen or that the yurt has moved over the past couple month if the outside circling ropes were not tight enough. Untie a little bit the outer ropes (watch for any fragile items like vases or babies in the yurt! :-). Lift the 2 bagaans (central poles) and twist the yurt back in place. You might put a shim (a few inches up to a foot) under each post). Tighten the outer ropes back.

3. Uneven walls:
if only some of the huns are not square to the toono, it is that the walls on one side are higher than the other (or your platform uneven).

4. yurt leaning on one side:
Push it back in place from the outside. Better anchor it in winds (toono central rope)

It could be a combination of the above. Also there are different qualities of gers on the market and this too can have a big influence. One way or the other, if you do not see any major cracks on the toono or bagaans, your ger will be safe and you can wait until warmer days to take it down and back up if you can't straiten it easily with the above tips. Make sure the outer ropes are well tight.

You are welcome to give us a call on our toll free for more details 1 888 476 6899. Ask for Yves

Happy yurting!

Yves - GroovyYurts

[Groovyyurts]

Originally Posted by warmwoolenmittens

from what it looks like i think

groovy yurts

and

suntime yurts

(west coast) import from the same company in mongolia that makes these, so they should be practically the same.

‎
Somehow I missed that message when I first responded. This is a great opportunity to clarify a couple things:

GroovyYurts does not import from the same company as Suntime yurts.

Roughly half of the Mongolian population lives in a ger. There are as many different qualities as there are ger manufacturers and it is a tough market place. You don't "import", you have to be on site, and work hand in hand .

It is not the proper forum for me to be advertising our company however I felt the need to clarify this information. We do welcome fair competition.

Best regards... and happy yurting!

Yves - GroovyYurts