Adfreezing and deck piers

Structure · Problems · printed page 39 (PDF page 40)

Book index entries

Adfreezing and Deck Piers Piers and Adfreezing Piers – on Deck – Adfreezing Footings – and Foundations Foundation – and Footing

Text in the illustration

even if the frost depth is above the bottom of the deck pier, soil adfreezing to the upper portion can cause heaving
sometimes plastic slip sheets are installed around the pier to prevent the frozen soil from gripping the concrete
deck
perspective
concrete deck pier
foundation wall
frost line
plastic slip sheets
cross section

Generated explanation

The illustration shows a deck attached to a house and supported at its outer edge by posts on concrete piers, with both perspective and cross-section views. In the cross section, the concrete deck pier extends below the dashed frost line, but upward arrows indicate heaving caused by frozen soil gripping the upper portion of the pier. The annotation explains that extending the pier below frost depth does not by itself prevent adfreezing-related movement. Plastic slip sheets around the pier are identified as a means of preventing frozen soil from gripping the concrete.