The weakest link is not the post-to-rim-joist connection, but the rim joist to the floor framing. 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. Typically I'll use the ABAz with a 1/2 anchor bolt. Curved, multi-level, other unusual shapes will require additional review by an engineer or other professional. Deck post sizes - 40 psf Live, 10 psf Dead: Height (ft) Load Area (sq. His work has appeared in “Family Handyman” magazine, “Popular Science,” "Popular Mechanics," “Handy” and other publications. code for nailing they will still check, may warp and will shrink at the splices which allows moisture to get trapped with dirt promoting the compromise of the beams over time. As a practical exercise we will choose a deck that is 10 metres long and 6 metres wide. Decking posts are buried into the ground and generally sit at the four corners of the deck. Our load area is 10 x 12 = 120 feet and according to the chart, we need 6-by-6 posts regardless of how high the deck is. diameter center footing size and Table B3 calls for a 16 in. Measured to the underside of the beam. R507.8.1 Deck Post to Deck Footing. Building & Construction, How to Cut & Install The remaining half of the deck will again be split into two parts to be supported by the two corner footings. The square foot area calculated as described translates directly into post size on the table. Most local building codes permit 4-by-4 posts 10 feet on center for all but multistory decks.. These are the beam size tables I use from the UBC code I find they still work well, I laid them out so they are easier to read and I found them better than the interior IRC table or the new deck prescriptive. How to Determine How Much Lumber for a Deck. Decks that are going to be built higher than just a few feet off the ground will likely need something more substantial than a simple 4×4. 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. 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. The weight of a simple roof over the deck is taken into account when using the tributary area method. Bolt the posts to the inside of the rim joists. The building department will accept sketches done by hand, but a set of neat drawings generated by a computer-assisted design program looks professional and will make getting the permits and required inspections easier. So you have exactly 4' between each deck post. If you have to use a built-up I suggest placing a flashing cap or membrane that won't break down and not use the ardox (threaded nail) as prescribed but use sds screws or thru-bolts. Posts must be plumb, so they have to start out with square ends. A larger beam can span a greater distance, requiring fewer but larger footings. In turn, the program designs your deck based on the building codes of your state. © Alter Eagle, This page last modified on Wednesday, February 16, 2011, Deck post sizes - 40 psf Live, 10 psf Dead, Load Area (sq. 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. The posts are at the 10' point in the deck, out from the house where a beam will be positioned to support the deck. 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. Attaching Deck Railing Posts . 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". There are two approaches to designing a deck and selecting the right-size components, such as correctly sized deck posts. With the min. Design / Build, Website Design by Owner Installing deck railing is easy if you use an anchored handrail system. post and the edge of the deck = 2’) and half the distance to post #2 (half of 8’ = 4’). Also on triples use 20d like we used to not the 10d. The weight of a simple roof over the deck is taken into account when using the tributary area method. © Copyright 2020 Hearst Communications, Inc. Decks building tutorials and design tables, The frequently asked questions on how to build decks for Northern California In this case, the beams are 10 feet apart (ledger to beam = 10 feet) and the distance between the posts is 12 feet. The size and spacing of footings tie directly to the maximum spacing between posts of the beam they support. A new table in the 2018 version of the IRC, Table R507.3, specifies footing size as it … We live in the beautiful wine country of Northern California. DECK POST SIZE MAXIMUM HEIGHT (see footnote a) 4 X 4 8 feet 4 X 6 8 feet 6 X 6 14 feet Footnote a: Measured to the underside of the beam . Beyond that amount, it becomes very difficult to meet the safety requirements. Connection at the four corners of the size and spacing of posts is 72 on... Support system once constructed you go by the load area ( sq base ( left ) uses a anchor. Is taken into account when using the tributary area method left ) uses a 5/8 anchor bolt for loads. A 8'x12 ' deck have contractors may feel comfortable opting for the smaller post sizes for Residential deck.! Professional deck designers and deck design software programs select the post size is determined by the area... 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