Free Deck Plans
Free Deck Plans
Choose from hundreds of permit ready designs. Our deck plans include a detailed framing plan, footing layout, material list and typical details. These plans are free to download as pdf files that can be printed to 1/4" - 1' scale on 11x17 paper.

Email this Article

Deck Joist Sizing and Spacing

Joists are the repeated structural members that are used to build a deck frame. The minimum size joist to be used in deck construction is not a stand-alone consideration, and is related to the number of footings and beams that will be installed. In general terms, joists spaced 16 inches on center can span 1.5 times in feet their depth in inches. A 2x8 up to 12 feet; 2x10 to 15 feet and 2x12 to 18 feet. The larger the deck, the larger the joists.  In typical deck construction, with a ledger on one side of the joist and beam on the other, the size of the joists is driven by the size of the deck based on the general maximum spans mentioned above.

For conventional guard rail post installation, bolted to the side of the framing, larger framing will provide for more strength in the rails. For upper level decks 2x10 is recommended as the minimum size to use for strong guard post connections. 2x6 joists should only be used on ground-level decks that do not require, and will not provide for, any guards.  Similar to guards, if stairs are to be hung from the side of an upper-level deck, 2x10 as a minimum is recommended, as it will exceed the depth of the first step.

Joist hangers are used to attach the ends of joists to the face of a beam or a ledger board. If you identify a crown in the board you should always install it upwards. The crown will eventually settle after completing construction and should stiffen in the proper position after drying.

The layout term for joists is “On Center” which is the center to center measurement from one joist to the next. Most decks use 16" on center spacing for joists. Most decking is not strong enough to support longer spans than 16". Some builders reduce joist spacing to 12" on center to strengthen the deck frame or to increase maximum allowable joist spans.

Laying Out Floor Joists
website website link
cures for hiv virus in human hpv viruses
oral chlamydia treatment std diseases can men get chlamydia

Using a scrap piece of wood as a guide to locate the first joist in the situation of an angled corner.

Marking joist locations at 16" on center spacing on the header with a marker.

Installing a joist over a beam. Make sure the top of the joist is flush with the header.
link how to cheat wife what is infidelity
wife cheated on me why do husband cheat why do women cheat with married men

Notching a joist over a beam. This joist was 1/4" higher than all the others. You can notch out a section of the joist or add shims to a narrow joist to even out the top of the deck frame.

Using a palm-nailer or hammer to install a Simpson Strong Tie LUS210Z joist hangers with 1-1/2" teco nails to the ledger board.
cures for hiv urine test for gonorrhea and chlamydia hpv viruses

Measuring the 2x10 pressure treated joist length to prepare for cutting. Use a speed square to square off your joists.

Installing 2x10 pressure treated joists at 16" on center. Be sure to install the joists crown side up.

Installing a Simpson Strong Tie H2.5Z Hurricane Tie for every joist to beam connection.
cures for hiv what is hpv in men hpv viruses

« Prev Next »


Comments, Questions and Reviews


I am building a 30 x 16 deck attached to my house on both the 30 foot side and the 16 foot side (it’s an L-shaped Bi-Level. It is supported by 6 x 6 columns every 8 feet on the front with a 2 foot cantilever. I would like a single 16 foot beam in the middle of the 30 foot length with no middle support posts. What size/type beam would I need? Should I use 2x10 or 2x12 joists. I want to run them parallel to the 30 foot side of the house so my finished decking runs the 16 foot length. Thank you

posted by dpino at 4/17/2015 10:47:14 AM

I want to know the time consumed by a worker for framing and decking of deck. 1) Measure, Marking and cutting the rim joist. 2) Attaching the joist 3) Attaching the decking 4) Cutting the excess decking Please reply soon for the above 4 points the time consumed by the worker. thanks.

posted by h_modh at 9/24/2014 10:19:28 AM

I have been in the carpenter/construction Industry for some 28 years and your question makes me think....why do you want to know this... every lay out is different and your skill level affects the time consumed to do the layout. For someone to come out and layout you deck or fence requires some years of experience. Based on your landscape and site situation. If you would like my best "guess at the time involved please send me a reply.

posted by Firepit Eddy at 1/18/2015 8:39:14 PM

I''d like to see how to install posts on a deck that is 2'' or more above ground. I was told they (the posts) have to be inside of the deck structural framing. I have composite decking also, already in place. My deck is about 5'' 6" above ground.

posted by KP at 7/26/2014 10:02:59 PM

That was supposed to read 5 ft 6 inches above the ground

posted by KP at 7/26/2014 10:04:40 PM

The code on decks has changed since my deck was built. The joists are spaced 20 inches instead of the new code of 16 inches. What can I do to correct this so my deck passes inspection

posted by Fran at 5/28/2014 12:12:35 AM

You can install a new beam between each joist.

posted by mike at 5/28/2014 8:58:43 AM

Fran, you can add a new Joist between each existing joist. Not easy to do if your deck joists span more that the basic 10-12 feet

posted by Firepit Eddy at 1/18/2015 8:43:32 PM