Decks, Patios, Porches and Docks - Deck Supports

If I build a deck 10' x 21.5' approx. 1.5' off the ground how many supports should be used for the width and length. I don't want to overkill with supports for the extra cost involved. I was thinking 3 per side for the width and 4 for the length with one side attached to the house. Thanks for your time.

I am assuming that it will project 10' from the house and run 21-1/2' along the house, and the decking will run either parallel to the house, or diagaonally. The spacing of the girders, and posts under those girders will be determined by what you use for joists and girders. If I were building the deck, I would use 2X6's at no more than 20" O.C. for the joists, and either 4X6's or double 2X6's for the girders. I would make the deck free-standing, rather than attach it to the house, so I would have 3 girders -- one about a foot from the house, one 5' from the house, and the third at 9' from the house. The posts under those girders would be spaced no more than 5' apart with a 4X6 girder, or no more than 4' apart with a dbl. 2X6 girder. I would set the posts at the end of each girder in a foot from the edge of the deck.

If you stay with the plan toa ttach the deck to the house with a ledger, simply eliminate the girder closest to the house and move the center girder about 6" closer to the house. Nothing else changes.