The grooves in a standard deck block are typically around 1.5 inches wide and 1.5 inches deep, designed to securely hold a 2×4 or 2×6 joist, depending on the specific deck block design; the post-receiving hole in the center of the block is usually sized to fit a 4×4 post.
Key points about deck block grooves:
- Size variation:Dimensions can slightly differ based on the manufacturer and model of the deck block.
- Function:The grooves allow for horizontal attachment of the deck joists to the concrete block.
- Post support:Most deck blocks also have a central hole designed to securely hold a vertical deck post, usually a 4×4.

