2017 01 19 nbsp 0183 32 Here we are finishing up our concrete footers by adding the bracket into the wet concrete Check out our full video on the concrete footers for building a de Footings are an important structural component of any post supported structure Some simple math is needed to ensure the footing is the correct size Armed with the knowledge in this guide anyone can understand and comfortably discuss the footing sizes needed for their project with an inspector or other building official What Size Rebar for Footings For most house and garage footings 4 rebar – or 189 diameter – is used Larger is acceptable too although adjustments may be needed to ensure proper coverage is still achieved If you live in Canada then this is about 13 rebar – 13mm Deck footings that require rebar will call for 3 or 10mm rebar I m building a pergola over a paver patio The pergola will dimension 11 x 11 5 on center of post with 6x6 posts 4 posts tied together with sandwiched 2x12 beams I ve laid out footer locations and am about to dig for 8 quot sonotube forms The footings will be set 2 5 quot below finished grade and I ll use Simpson Strong Tie Elevated Post Base anchors EPB66 so that I can lay pavers on top 2021 12 05 nbsp 0183 32 What size sonotube for a 6 215 6 post 10″ Should you use 4 215 4 or 6 215 6 deck posts Deck posts must be a minimum of 4 215 4 according to the IRC but many jurisdictions require a 6 215 6 post as a standard To avoid code violations many deck builders choose the 6 215 6 even if the 4 215 4 is acceptable However for most decks 50psf is a safe load value

Source Table 403 1 CABO One and Two Family Dwelling Code 1995 More footing dimensions Footing thickness 8 to 12 inches Footing depth varies based on frost line and soil strength some footings can be shallow while other must be deep Concrete Calculator Figure out how much concrete you ll need for your footings You can look up the recommended footing size Span Lengths and determine the number of footings needed based on the size of the deck I prefer a double 2x beam because it can rest on notched 6 215 6 posts The 2 1⁄2 in thick leg on the back of the notch bolts to the beam Triple 2x beams can make sense but require a structural connector to join to the post 2020 08 04 nbsp 0183 32 Now I will be mounting 6x6 posts j bolt Simpson post bracket In terms of load the 2x8 joists will span 9 ft and sit on the beam double 2x10 1 ft cantilever I read that either 10 or 12in diameter tubing are fine but now when I Dotted lines Trib Area of each post footing Yellow outline Largest Trib Area TA 6 x 7 42 sq ft post footing beam ledger VII Example –Deck post footing size calculation Side View Top View TA 8 x 5 5 44 sq ftExample –Deck post footing size calculation Side View Top View TA 8 x 5 5 44 sq ft Note this deck has a ledger green which means the deck is connected to the house which will carry part of the load In our example we can look at any post footing to determine its tributary area We will examine the calculations for Post 1 and Post 2 A single post will have one footing to

2006 11 02 nbsp 0183 32 Otherwise check the local regs and verify the size of footing you will need There is a product available at big box stores that is basically an inverted funnel The bottom of the tube is the correct diameter for a footing and over about a four foot rise it narrows to a 6 quot or 8 quot inch diameter It is made of plastic and meant to be left in the Pole Barn Footer Calculator 1 This is the combination of the top chord live load and top chord dead load on the truss drawing 2 Typically between 1500 psf and 3000 psf 1500 is really poor soil and 2000 3000 is typical Without a soil test you don t know your true bearing capacity 2014 12 04 nbsp 0183 32 Consultant Bachelor s Degree 4 094 satisfied customers I need to span 16 feet for a roof over a deck one side will I need to span 16 feet for a roof over a deck one side will be on the other on a 6x6 post will 3 2x10 20 foot support the These footing size requirements are to ensure enough soil bearing to prevent the joist from sinking in the ground How many posts do I need for a 12 215 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 Using doubled boards you will then need to build beams on the top row of the posts to Concrete Requirements Size Chart Close Concrete Requirements Size Chart Use the chart below to determine concrete requirements for your project Sonotube 174 concrete forms are available in the following diameters Sonotube 174 Finish Free 174 12 quot 48 quot Sonotube 174 Round 6 quot 36 quot Sonotube 174 Commercial 6 quot 60 quot Concrete Requirements Expressed in cubic yards for columns

Column footing size for 4 storey G 3 building for 4 storey G 3 house or in simple 4 floor building general thumb rule using standard 9″ thick walls we recommended size of column footing should be 6 215 6 215 6′ 1 8m x 1 8m 215 1 8m for isolated footing shallow foundation in gravel and sand soil with higher bearing capacity in which width dimensions is 6 215 6′ and depth of floor plan footing plan the plot size is quot a quot size 8 1 2 quot x11 quot if plotted on quot c quot size paper 17 quot x22 quot the scale is 2x the stated scale 8 10 1 2 quot 6x6 post 12 3 quot 6x6 post 6x6 post 9 4 1 2 quot 7 4 1 2 quot 2x12 beam inset 1 1 2 quot into outside of post 12 5 4 1 2 quot 3 4 1 2 quot 9 metal siding engineered truss 2x12 beam inset 1 1 2 quot deep into outside of post 9 grade 1 4 1 2 4 quot metal roofing 2x4 Use a 6x6 post for your pergola The 6x6 post is the minimum recommended size in order to provide the strength rigidity and the proportion in the final appearance The post saddles for the Deck Foot Anchor have a lateral slide feature which allows the saddle to be moved up to about 2 quot to make up for any errors in the location of your pergola footings Footing Chart For size and number of rebar see chart above A A 6 Minimum cover typical 6 3 10 1 Rebar Line 2 Directions Total 1 Notes A Concrete to be a minimum of 3000p s i 20Mpa normal portland cement type 10 or type 50 as required maximum 3 4 20mm aggregate 3 75MM slump B All rebar to be tied at intersections Follow position diagram C 2000 09 23 nbsp 0183 32 I saw a post regarding the best material for a fence post footing and it brought up a similar question I will be building a pole barn in the spring with PT 6x6 posts as the frame I have to have the posts or footings 42 quot below grade for frost considerations My plan was to put 12 quot wide 4 high sonotubes in the ground fill the first 1 with cement then add the posts and backfill

When using wood posts get foundation grade 6x6 treated poles or posts When using a gravel footing nail a square of pressure treated 2x10 or 2x12 to the bottom to act as a foot Use only hot dipped galvanized quot Z max quot or stainless steel nails and bolts with PT material Don t rely only on the bolts to hold the beams Set the beams on top of the wood posts and connect them with 2020 04 17 nbsp 0183 32 The depth of your hole should be about 1 4 of the height of your post For a 6x6 post the diameter of the holes should be about 12 inches square As a rule the width of your post hole should never be less than 10 inches You want holes deep and wide enough to easily support a standard 4x4 post Click to see full answer Concrete Post footers are required for all posts except entry door posts Footers are typically poured from local concrete providers and are not included in the material or labor pricing Treated posts Side post 8 on center gable end posts 8 or 10 on center 24 wide barns 4x6 treated posts 8 on center 30 wide barns Pergola Post Installation Mounted on Concrete Footer or Existing Slab The easiest method of installation is to dig footings to the correct depth below the frost line in your area and use post mounting hardware to attach the posts to the concrete footings or existing concrete slab as follows Order the 8 foot or 10 foot post option and add the post attachment hardware to your 2018 04 05 nbsp 0183 32 Super Moderator Joined Mar 13 2005 183 23 028 Posts 2 183 Apr 3 2018 Just for reference an 8x8 post is 11 3 inches corner to corner If you want a minimum of 2 inches all the way around that means you need to add 4 inches I would use a tube less than 15 inches