How to Determine Proper Lumber and Size when Building a Patio

Building a patio is a home improvement job that you can do yourself with the right tools. You will also need to plan out your patio before you begin in order to determine type and the amount of lumber you will need.

Planning the Deck

Determine where you would like to install the deck. Determine the size of deck you would like to build. You will need the length and width dimensions. You will also need to determine whether the deck will be installed on the ground or on supports. A deck that is built on supports will also need stairs. Use your chalk line to mark the location of the deck installation. If the deck is going to installed on supports, mark the location of the steps. You will need to clear any plants, stones or other items from the area. Make a drawing of your deck plans that shows a one half inch to the foot scale

Ordering Dimensions

When ordering your lumber you will need to specify the dimensions in a particular order. The thickness dimension first, then the width and finally the length. The thickness and width dimensions should be ordered in inches and the length dimensions should be order in feet. The quantity of lumber should be provided before you give the dimensions.

Raw Lumber Dimensions

Raw lumber typically has two dimensions. The nominal length dimensions are the actual measurements of the lumber. The nominal thickness and width dimensions differ from the actual measurements. The nominal thickness and width dimensions are typically a half inch larger than the actual measurements. When you are determining the amount of lumber you need, use the actual measurements but when you order your lumber, provide the nominal dimensions.

Lumber Moisture

Wood material holds moisture and this can affect the dimensions of the lumber you order. Lumber with a moisture content is referred to as dress green lumber. The order dimensions you provide will be based on dried lumber but the order can arrive at your location with varying moisture content in the wood. The lumber dimensions can differ by one sixteenth to one quarter of an inch, depending on the width or thickness and the amount of moisture in the width.

Calculating Lumber Requirements

Determine the square foot area of the deck you want to build. To do this, multiply the width of the deck by the length of the deck. A piece of lumber that is five fourths of an inch by six inches by eight feet will be enough to cover a deck area of four square feet. Divide the area of deck you want to build by four. Round your calculation to the nearest board. This calculation will be the number of boards you will need for your deck. When you are determining your lumber requirement, you will also need to add in an amount for waste and for incorrect cuts. On average, a fifteen by fifteen foot deck will require seventy boards that are five fourths of an inch thick, six inches wide and eight feet long.

Stair Lumber

If you are building stairs, you will need to include a calculation for the steps. Steps are generally one foot deep and four feet wide. If you order boards that are six inches wide, you will need two boards four feet in length for each step you build.