Spacing For Deck Flooring

This sample table gives minimum floor joist sizes for joists spaced at 16 inches and 24 inches on center o c for 2 grade lumber with 10 pounds per square foot of dead load and 40 pounds of live load which is typical of normal residential construction.

Spacing for deck flooring. How far it must travel between beams or between a beam and a ledger. Proper side to side deck board spacing allows for air water and debris to flow around the decking leading to a long lasting low maintenance deck. 5 4 x 6 is produced specifically for decking and is milled with a radius edge or bull nose. True floor joist span calculations can only be made by a structural engineer or contractor.

Adjust the spacing between deck boards gradually over the next 10 rows of decking until the distance to the house is equal. Calculating deck joist spans the required width of a joist depends on its span. Some builders reduce joist spacing to 12 on center to strengthen the deck frame or to increase maximum allowable joist spans. The goal is to have about an 1 8 inch gap the diameter of an 8d nail between boards after the decking has dried to its equilibrium moisture content.

For instance joists that are placed 24 inches apart must be wider than joists placed 16 inches apart. When securing the decking it is important to leave adequate spacing between the boards for water to drain. Most decks use 16 on center spacing for joists. Spacing between deck boards provide a few critical functions.

2 x 6 boards available in 12 16 and 20 lengths. For a more rigid feel 12 or less may be preferred. Most decking is not strong enough to support longer spans than 16. 2x6 is thicker and is stronger but is also more expensive.

If adding additional framing be sure to keep all boards level and in plane across the tops. Our square edge boards install traditionally like wood with deck screws. If you install your decking using wet boards pressure treated decking that has not yet dried out then you should install them with no gap as a gap will be created as they dry and shrink. The primary function is to drain water from the deck.

For timbertech azek decking it s recommended to have a minimum 1 8 to 1 4 side to side gap between deck boards. Proper deck board spacing should have a 1 8 inch gap after the decking has dried out. Joist spacing for composite decking. Deck spacing isn t anything to take lightly.

Deck joist spacing should never exceed 16 on center with the exception of max deck boards which allow for maximum 24 on center. The last board won t look good if it s skinny or cut at an angle.