Deck Post Footing Size

In this case though i couldn t find a current source with a table that shows allowable tributary areas for various sizes and wood species of posts.

Deck post footing size. Typical post size is a pressure treated 4 4. Step 2 dig footing holes about 6 inches deeper than required. Diameter center footing size and table b3 calls for a 16 in. Use added batter boards and string to mark rows of posts.

Of course you can get a 24 base size and it will spread weight over an even greater surface area. To calculate the load you should use 40lbs per square foot for live loads these are variable loads that are dynamic such as the weight of. The evolution compression post base will make any deck footing look fantastic because the connection mechanism is completely hidden deep. Others err on the side of caution and dig unnecessarily oversized footings.

In order to determine the proper size for your footings you will need to establish how much total weight they are going to have to support and what kind of soil they are covering. Step 3 fill the bottom of the hole with 6 inches of gravel and compact the gravel with a 2x4 or wood post. Deck footing size chart. My calculations came up with 15 3 4 in.

This is a permanent footing and is great for large or high decks that need very strong footings. This is between 3 and 14 in concrete. Post spacing should be even. A comparison of the footing sizes i calculated for the example deck resting on 1500 psf soil in the sizing deck footings article and dca 6 table b3 shows an almost identical result.

A third option for math averse but cautious deck builders is to refer to dca6 s prescriptive footing sizing table which supplies footing sizes based on the beam span and joist span. Footings typically must extend below the frost line to prevent shifting during freeze thaw cycles. Once you decide the distance measure from the house for the first row of boards. Post spacing is going to depend on your design local building codes the size and length of your beams and the size of your posts.

When the irc leaves us hanging we can often find an alternative rope to climb. For aesthetic reasons most deck builders size them all based on the worst case loading. There is little material cost to a buried post footing. Sizing deck footings assuming a minimum soil bearing capacity of 1 500 psf 8 inch diameter concrete piers bearing on square footings measuring 2 feet on a side and 9 to 11 inches thick are adequate for most single story decks where beams are spaced 14 feet apart or less and joist spans are 14 feet or less see table below.