Yurt in northen Scandinavia: Tips?

[hierony]

You'll probably be alright for snow loads--I like MTRod's link with the yurts that look to have 45+ deg slope. A 45 deg roof coupled with a warm, slippery surface gives a slope factor of 0.38 (ie, your roof will see 38% of the ground snow load, excluding other factors; can vary). Heavy wet spring snow can be 50% water by volume, delectably light & fluffy snow is probably <5%.

As for roof pole/rafter size, it isn't just the dimension of the poles that determines the total roof strength but also the total number of poles. Parallel force/compression works a bit differently from perpindicular bending and I need to think how best to describe it here... Also, I think there is an advantage to using whole saplings over sawn lumber, but I need to look that up. Baganas significantly reduce the unsupported span of the roof poles/crown ring, greatly increasing the allowable load on each pole.

My yurt was built just outside Budapest, Hungary--the maker used local companies for cotton/jute canvas and a synthetic geotextile felt

insulation

but also had options for architectural fabric from Sioen Industries in Belgium.

Any particular reason you're building on a trailer instead of a platform? What kind of wood stove you plan on using?

[Groovyyurts]

Tjena!

- For snow resistance, Hierony's comment to add central poles under the

dome

(even if only temporary) is a good idea (add them when you leave for a long time in winter).
- 30' is a BIG yurt in such climate. You will indeed have to use heavy duty engineering to resist snow loads if you are not there to remove the snow. Have you thought of smaller diameters, even if you connect two yurts?
- for the damp period, vents in the platform and small solar ventilators somewhere in the

dome

or roof can be a great help, at least to avoid condensation which is the best start for mold.

Har det bra!

[Seigan]

Thanks guys for all your help.

Now the wooden fram is nearly finnished. I use 22x45mm for the wall (sturdy as hell yet flexible) and are put at 70 degrees instead of 90 which make it even sturdier. The distance between them standing upright are 30cm.

The roof beams are 45x145 mm (c24m/c24+standard) and will sit 60 cm apart (so I get 40 beams) at the bottom. They will be at 40 degree angle. Where it is placed the building standard is to calculate for 200 kg per square meter in snowload. Usually the roof beams are 45x170mm (c24 standard) and sit at 120 cm apart or more. On half my roof they will be less then 30 cm apart. I have consulted local carpenters an engineers and all of then have said the dimentions should be enough. I will also have space to have 40 more beams in the crown, total of 80 beams 30 cm apart at the bottom an 15 cm in the middle, if nessecerly but all carpenters I have talked to deam that way more the I need so...

In addition I am planning to set a 10 mm harden steel wire around the roof beams, vertical support poles to take the pressure of the walls and a small wire to hold all beams together as as safety line if some beam would break. Temporaly vertical support poles for the crown while away sounds like a very good idea that I will surely implement.

Furtermore I've found a windprotection cloth called "Bison 100 windprotection" that protects against wind and water 100% from the outside but let steam out from the inside. It breath very well and acts a bite like gortex. My plan is to put this between the canvas and the

insulation

layer. The hope is that it will protect the wooden construction and insulation from condence and if the canvas leak a bit.

I am also wondering about put up a heat barrier (bubblewrap clad in aluminiumfoil) between the windprotection and the canvas. It certainly entraps the heat but the question is what type of bi-effects I will get as the heat barrier also acts kind of as a moister barrier as well though it do not breath at all. I am wondering if I am not shoting my self in the foot by adding it and entrap the moister in the construction instead of letting it out through the canvas.

For the floor I have 170 mm tree-fiber insulation (Hunton Flex) which has the same or even a bit better value then ordinary rockwool but not at all bad for the health. It is also capable of buffer moister when it is wet and letting it out when it is dry (which rockwool do not do) witout attracting mold which helps keeping the construction healthy. I will also add a water floor

heating

system to even out the spread of the heat (and it enables me to multiple heatsources).

I hope this will be sufficent to withstand the winter

[Bob Rowlands]

I'd install no material I thought woyld trap

moisture

inside the yurt UNLESS the yurt was very drafty. Thanks for the deets on your build.

[Jafo]

If you will be living in the yurt full time, the snow will just slide off most of the time I think you will find. Very interesting build. Please post pics when you can.