Ground Anchors are a good option too by: Editor - Rich Bergman
Should have mentioned there is one product I have used which has been on the market for a few years now and is an extension of the a fence post anchoring system.
It's called the Deck Foot Anchor and it works very well for floating decks not connected to houses.
Drives into the ground with a hand held electric impact wrench. In or out. Just as easy and even your grandmother could probably do it.
Now, the load plate is set on the ground but hte auger is drilled at least 2' down so it takes hundreds of pounds, maybe 1000 pounds or more to pull it out.
But it will rise and fall in constant contact with the surface as the soil expands or contracts over the seasons. But it doesn't heave out like a post.
For ledger attached decks you have to go below your frost level or if you use an engineered helical anchor it has to be torque rated so that it will not lift up during frost heave. They can drive those down as deep as needed.
But it takes you into totally different price range. But might also be perfect depending on what you are building.
May 30, 2010 Rating
Support post hole depth by: Editor - Rich Bergman
If you are in a northern climate where there is heavy frost you could easily have frost down to 48". If so you should dig to 60" with a footing. Your local building department will tell you what the local minimum depth is based on your climate.
Even in the most southern climates a minimum of 12" is prescribed by codes.
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