Circular footings, on the other hand, need to be 23 inches in diameter. Tables for the minimum joist spans in California's moderate climate regions, How we build a closed in riser stair for decks with a skirt for solid railings, Deck stair total rise table with calculations for riser heights and number of treads, Alter Eagle These are the simpson strong-tie connections I use there are many other options available, The loading condition is 40 psf live and 10 psf dead. To use this calculation, you need a copy of the tables found in the book "Wood Decks: Materials, Construction and Finishing," published by the Forest Products Society in 1996. Two reasons; first, it’s easier to dig; second, the wider deck footing provides enough room for me to move the post around in the deck footing while maintaining the minimum 100mm clearance around the deck post. Typically I'll use the ABAz with a 1/2 anchor bolt. Conversion bases are available to fit the following Post sizes: 3" ~ 3 1/2" ~ 4" ~ 4 3/8" ~ 4 1/2" ~ 5" ~ 6" ~ 6 1/2". Also on triples use 20d like we used to not the 10d. The height of the post shown in MRC Table R507.4 is measured from the underside of the beam to the top of the footing. No Lateral loads considered You can design your deck using one of the many free online deck designer programs, or you can make all the calculations yourself using pen and paper. Constructing a deck may seem like a straightforward project at first glance, but a lot of structural engineering goes into designing and building a sturdy deck. That portion of the International Residential Code is based on the National Design Specifications for Wood, which indicates that a 6- by 6-inch post is adequate for all but the most extreme residential deck. The remaining half of the deck will again be split into two parts to be supported by the two corner footings. If you multiply the area of this section 5’ x 5’, you will get 25 square feet. The weight of a simple roof over the deck is taken into account when using the tributary area method. R507.8.1 Deck Post to Deck Footing. I prefer the adjustable 1" stand-off bases for decks above 30" I also keep my piers a min. Crown Molding, Finishing Carpenter There is an additional advantage to using a design program to calculate the sizes of the structural materials for your deck: They produce a detailed set of construction drawings. Where to position posts in deck footings. ft)= beam spacing x post spacing. This will help you visualize the deck’s support system once constructed. For a total of 6’ Therefore the tributary area of Footing #1 = 6’ x 7’ or 42 square feet. You can multiply this area by 55 lbs per square foot loading to … Maximum spacing of posts is 72 inches on center. requirements Lag screws and bolts shall be staggered per diagram below Lag screw tips shall extend beyond the inside face of the … Posts shall be restrained to prevent lateral displacement at the bottom support. Normal decks are considered to have a dead load of 10 lbs. Measured to the underside of the beam. The tributary area is the portion of a deck supported by each deck post. Always refer to your local building codes or a structural engineer this is how we build our decks, Deck footing & pier sizing for California, Deck connections for California's #4 earthquake zone. In this case, the beams are 10 feet apart (ledger to beam = 10 feet) and the distance between the posts is 12 feet. 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