Hexayurt building went well – a 7/16″ Oriented Strand Board (OSB) structure with 4 inch wide, 32 gage galvanized flashing as the ‘tape’ to hold it together. Being familiar with standard construction methods, I had my doubts concerning the structural integrity of a tension srtucture. I have been converted after this project.
The opposing walls gave strength to each other and to the roof. Once all panels were in place they could support people walking on top. Using minimal resources we were able to construct a space of 166 sq feet in two full days – at a cost of $132 for panels and flashing- not considering paint, tar, screws, nails, and 2x4s used in the walls. We decided to go with six foot walls instead of eight, saving us three sheets of OSB and making the peak a more manageable ten foot height. The main concern was that the OSB would take on moisture over time, swell, rot, and lose its rigidity resulting in decreased life of the structure. Precautions were taken. Marcin, Rich and I site prepped the building site and materials in one day – with the LifeTrac tiller as the main workhorse. Site prep included leveling the building area by means of rototilling then pushing earth by hand and laying down and tamping fine gravel where the walls would sit to protect the OSB from wicking up moisture from the ground. The nature of compressed wood products is to take on moisture at the edges where pores are exposed. Thus, we used latex primer around the edges and roofing tar around the base of the lower panels prior to assembly. We cut all the pieces to size by day 1.
Day two started with the manufacture of the six walls. The full (4 by 8 foot) sheet and the half sheet (2 by 8) were joined length wise using a eight foot 2×4 laying flat with 30 degree end cuts. Like this /__8 foot__ . We prepunched holes in the 4 inch wide flashing so we can screw with ease. On top of each panel, we attached a shelf made from a 2×4 – so we could stand the roof panels on this easily. With the leading edge flashed we screwed each panel to the next quite quickly using our foundation as guide.
There were challenges – the roof was not that easy to put on – it required at least three people to position and support each roof triangle as it went up – and it took some messing around to line the roof panels up to meet at a single point. Next, time, we’ll build the roof on the ground – and then lift it into place with at least 4 people. This would be doable with 6 foot walls – but would be rather difficult with 8 foot walls – for anyone wishing to try this at home.
All in all, our experience was thoroughly fulfilling. We conclude that the Hexayurt is a remarkably materials efficient, cost-efficient, building-time efficient, and structurally-sound tension structure. This is a secret weapon for temporary housing – as we begin CEB construction. I suspect many more people could use it if they knew about it – other farms, villages, retreats, and other temporary housing situations – where you can literally bring the materials with you to an uninhabited place – and have ready shelter that will last about 10 years if appropriate rain protection measures are taken if you use OSB. Thumbs up to Vinay.