How does frost heave affect conventional deck construction?
When footings are not buried below the frost line or without smooth edges, damage can occur. During cold seasons, ice lenses form, exerting pressure against the rough edges of the concrete post, forcing it upward. A pocket will form under the post where the soil is not affected by frost. Dirt particles and water will then accumulate into this pocket. During the spring thaw, it is likely that the post will not return to its original position (due to the accumulation of soil deposits). When repeated throughout the life of the deck, this process of lifting the post can cause significant damage to the structural integrity of the deck.
