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BUILDING A DECK? Here are some deck building basics.

A deck is basically a floor structure supported on posts. Loads on the deck from people, furniture, snow, etc. are transferred from the decking, onto joists, to beams, down posts, to foundations and into the soil below. All of these components play an important role in the function of the deck and must be sized and constructed properly to make the deck safe.

PIERS

Deck piers must extend down to the from the frost line 42" and be large enough in diameter to support 1000 to 3000 pounds concentrated on them by the posts. The soil must be stiff and water removed from the holes before placing concrete. Deck posts should never be placed on an existing patio. Frost heave and the heavy concentrated loads may couse movement and premature failures.

POSTS

Typically posts are 4x4 lumber, however on higher decks, many builders will use 4x6 ro 6x6 lumber. Posts must be securely anchored to the foundations or embedded in the concrete.

BEAMS

Because of the flexibility of deck designs, it is difficult to give a basic rule of thumb for sizing beams. The beams size is dependent on the beam span, the number of beams proposed and the span of joists resting on them. Beams rest on top of th posts or are attached to the posts with bolts.

JOISTS

Joists are spaced at regular intervals; the most common spacing in 16". The following is a joist span table for sizing your joists. This can be used for #2 pressure treated SYP lumber at 16" spacing

Many times the joists are connected to the house by ataching a ledger board with lag bolts into wood or anchors into concrete. The joists are typically connected to the ledger board using metal joist hangers

DECKING

The deck surface is normally constructed of 2x4 or 2x8 lumber or 5/4x4 of 5/4x6 rounded edge deck boards butted together. End joints for the decking should fall over a joist.

GUARDRAILS

All decks that are 30" or more above the ground must have a minimum 36" high guardrail. This guardrail must have intermediate members that prevent the passage of a 4" ball. Guardrails typically use closely spaced balusters (thin vertical members) or criss-crossed latice to meet this requirement.