Seattle frostline Getting Started Discuss Seattle frostline in the Pizza Oven Design and Installation forums; Mine is built on straight sontubes down 4 feet. I flared out the bottom somewhat. Been through several winters here ...

[Neil2]

Mine is built on straight sontubes down 4 feet. I flared out the bottom somewhat. Been through several winters here on Vancouver Island with no problem.

My second choice would be to build it on a 6 inch heavily reinforced slab with no below frost line footings.

I think the frost heaving issue is overstated.

[kebwi]

You know, Wiley is my last name. :-) Anyway, I've only lived in Seattle two years and owned a house here one year, with accompanying winter, so the answer is, I have no idea. Maybe it'll be fine with slab-on-pebbles then.

I'm still open to further input of course.

Thanks.

[Neil2]

Frost heaving can be a problem with decks mostly. In that type of construction, each support is independent so you can get uneven movement. Frost heaving is mostly a problem in clay/till or silt/till soils. It is not a problem in granular soils or in heavily compacted soils like the natural "hard pan" common in the Seattle area.

With any structure you should plan for some movement, either by settlement or by frost heaving. A reinforced slab will move as one unit. (Unless it tilts so much that your pizzas slide out this is not a problem.)

[Johnbear]

I dont forsee any problems as I have a 10 year old 8x8 shed built on a 6x6 pressure treated rr tie foundation and that hasnt budged in all that time,,









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