I live in a cold climate and am building an unheated ten by fourteen roll off roof observatory soon, I hope. The soil freezes to about six feet/1.8 meters here. The soil is rocky silty loam. It is on a hillside, and sees runoff in the Spring.
If you built your observatory on a slab in freeze/thaw territory, what issues did you have?
- Did you insulate the slab? If so, how much insulation?
- Did you place wing insulation in the ground surrounding the slab? (The idea being to trap ground heat, so the area under the slab doesn't freeze and heave.
- Someone told me the slab should be built with grade beams on the perimeter. Thoughts? It doesn't add that much to the final cost.
- They also speculated that I could extend the grade beams past the north end of the observatory, and rest the roll off rail support posts on the beams.
- Another person said, no grade beams, just make the slab 6" or thicker. (I was going with 4" slab and grade beams.)
- I am placing a french trench on the uphill side of the observatory, to control runoff.
- Do you have trouble with the ROR rails twisting dues to frost heaves?
- Rail supports - bore holes bellow frost level and run cement to ground level, then attach the rail posts?
- Or set blocks on the surface for the posts?
Thank you for your help,
Edited by Scott123, 01 June 2020 - 02:44 PM.