After the ledger board is installed it is time to locate the footings using batter boards, string and some math.

Start by making the batter boards. Simply take two 1x4 stakes about 30" long and attach them together using another 20" long 1x4. You will generally need 2 batter boards per corner.

Place the batter boards about 3' outside of your rough footing marks by pounding them securely into the ground using a sledge hammer. The batter boards support string lines that are used to mark the exact footing locations.

On the ledger board make a mark representing the center of each post. Attach a string on the mark using a nail and tie the other end to the batter board opposite the ledger board. The idea is to make a grid that represents the center line of each post and the beams.

The string that marks the center of the beam should be parallel with the ledger board and the strings that mark the post center lines should be at 90 degrees to the ledger. Use the 3-4-5 method for squaring the posts strings to the ledger.

Once all the strings are in place measure diagonal corners, if the measurements are the same then the string grid is square. Once square you can mark the exact center point of the footings using a plumb bob. Mark wherever the strings intersect at the corners and at any point needed along the length of the beam.

Digging and pouring the footings

Now that you have established exactly where the footings go it is time to dig, form and pour concrete.

Depending where you live the code for frost protection varies. Check with the building department for minimum depth of footings for your area.

A small back-hoe is needed to excavate the soil so we can lay out the footings. Your deck plans will specify the dimensions of the footings. Form a pad at the bottom of the excavated hole according to your deck plans.

Using a "sonnet tube" form the rest of the footings. Using reinforcement bars to add strength to the remainder of the footings.

Before pouring you may need to have a building inspector approve the forms. Once you have an approval go ahead and order your concrete from the redi-mix plant. Be prepared when the concrete truck comes. Pouring concrete is a very time sensitive ordeal. Make sure you have all the tools ready for the pour. Tools like shovels, screeds and be sure to have the post saddles ready to be inserted into the concrete before it sets.

After a day or two the concrete will have set up enough for the back hoe to come back and back fill the soil around the footings and smooth out the site.

Everything done up to this point can be tricky for those with little or no building skills. You may want to hire a contractor to get you through to this stage of construction.

WIth the footings poured and back-filled you can move on to the framing.

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