Table of Contents
How many posts does my deck need?
The answer depends on the size and shape of your deck, the size of your footings, and the size of your beams. The larger the beam and footing size, the fewer footings that are required. For most situations, you will want to place footings and posts less than 8′ apart.
How far apart should deck posts be?
Layout and Footing Locations Starting with your perimeter, mark the location of each deck post to locate the fitting position. In general, posts should be spaced no more than 8 feet apart. Some builders position them every 4 feet for a completely rigid frame.
How many footings do I need for a freestanding deck?
Quick Attached Deck Footing Chart Size of Deck Beam Size Number of Footings 10′ x 10′ (2) 2×8 2 10′ x 12′ (3) 2×8 2 12′ x 12′ (2) 2×6 3 16′ x 16′ (3) 2×8 3.
How many 4×4 posts do I need for a deck?
The larger 12-foot side will have a post spacing of 6 feet at a minimum code requirement. That makes a total of eight posts that need to be installed on this average size deck. For aesthetic or symmetry reasons, more posts may be added.
How many posts are needed for a 10×10 deck?
A freestanding 10′ x10′ deck needs 4 posts, supporting two pairs of 2-ply non-incised 2×8 beam, upgrading the beam to 3-ply using incised wood.
How do you calculate deck posts?
Draw a line through the mid-span of the joists. Then find the mid-span of the beam that the post supports, and extend lines from there back to the line at the joist mid-span. Find the area within the lines. To calculate the design load for the post, multiply the tributary area by the combined live and dead loads.
How many posts do I need for a 12×16 deck?
A standard deck will need four footings parallel to the house, but they will need to be temporarily braced by 6 inch-by-6 inch posts.
Should deck posts be 4×4 or 6×6?
Deck posts must be a minimum of 4×4 according to the IRC but many jurisdictions require a 6×6 post as a standard. To avoid code violations, many deck builders choose the 6×6 even if the 4×4 is acceptable.
Can I use 4×4 for deck posts?
In the past, many decks were built with 4×4 support posts (also called structural posts). But these can bow seriously, even if a deck is only 3 feet off the ground. For that reason, we strongly recommend that you use 6x6s instead, even if your building department does not demand them.
Do freestanding decks need footings?
According to the main code provision for footings, the only requirement for building a deck that is freestanding is that it must have a minimum footing depth of 12 inches below the undisturbed ground surface. There is no need to extend a footing below the frost line, as is required for standard decks.
How many posts are needed for a 12×12 deck?
For an attached 12 x 12′ deck, you’ll need at least 3 footings, plus at least 2 more if you’re planning on building stairs with it.
Can I use deck pier blocks instead of footings?
Pier blocks can be used instead of footings for a ground-level deck not requiring permits. Any decks higher than 24” require concrete piles 10” in diameter and 48” below grade. These footing size requirements are to ensure enough soil bearing to prevent the joist from sinking in the ground.
How much weight will a 6×6 post support?
A 6×6 with 12′ span can support 2000 lbs. if you assume a conservative 1400psi bending stress. If you do a good job bonding the two members together, your double 6×6 can support more than 4,000 lbs.
Should I use 4×4 or 4×6 deck posts?
While there may be a handful of circumstances that only require the minimum 4×4 deck post, you will more than likely want to choose a 6×6 post for the deck. It provides more stability for larger decks, the ability to hold a heavier load, and more room for notching.
How much weight can a 4×6 post support?
2 Answers. Assuming it’s “Lodgepole Pine” (Idaho Pine and Ponderosa Pine is slightly less) and it’s grade is a No. 2 and better (no loose or missing knotholes), then a 4×6 spanning 18′ will support about 105 lbs.
How much does it cost to build a 20×20 deck?
The average homeowner spends $2,200 to build a 10×10 foot deck, $6,160 to build a 14×20 deck, and $8,800 to build a 20×20 deck. The cost to build a deck with pressure-treated wood, hardwood, or composite is about $25 per square foot, for both materials and installation.
How much weight can a 10×10 deck hold?
In short there’s no one right answer to “how much can my deck hold?” However, one rule of thumb to keep in mind while answering the question is that the answer commonly is that if a deck is properly designed, it’s built to hold 50 lbs. per square foot.
Should I use 2×6 or 2×8 for deck?
For upper-level decks, 2×10 is recommended as the minimum size to use for strong guard post connections. 2×6 joists should only be used on ground-level decks that do not require, and will not provide for, any guards. Most decking is not strong enough to support longer spans than 16″.
How many beams does a deck need?
While cantilevering can add width to your deck and eliminate the need for additional footings, posts and beams, sometimes it isn’t enough. A 20-foot wide deck, for example, would require two beams: one at 10 feet and one and 20 feet in order to support a deck with 2×8 joists spaced 16 inches apart.
How do I know what size beam I need for my deck?
Use “a” + “b” to determine the size of Beam 1. Use joist length “b” to determine the size of Beam 2. Joist size is determined by using the longest span joist (7′). The Joist Span indicates that 2x6s at 24” O.C. would be adequate for this span.
