I'll say it one last time.
1/2" pvc 20' lengths each end slid over a 2 or 3' chunk rebar stuck in the ground, then tied together with 2 or 3 lengths of rope length wise for securing the 'ribs/rafters' will withstand 2" of snow for days. No fittings and no poles in the middle , just open space like I said earlier Quanset Hut style.
Or you could build one really long sweat lodge to help clear out those toxins running round.
If it has to be dust tight the something else would be required but the question was about making a cheap temporary space and I'm simply offering an option that could expand from something to squeeze a fender in or put a whole bed on saw horses in that contains the blast materials. Your lungs are your problem...
