Decking Calculator

A decking calculator can determine the amount of material to build a deck. It simplifies the process because the deck size, type of material, and structure elements can all be included. Factors such as deck dimensions, load-carrying ability, choice of material, spacing of joists, beams, and decking boards are considered to determine the exact amount of material needed. Her are some Critical elements in a decking calculator include;

Deck measurement: Length and width of the deck surface. These define the total area to be covered by decking material.

Decking material: This defines the decking material, the board size, and the required material.

Board width: Influences the number of boards needed to support the decking.

Joist spacing: defines the distance between joists for the framing material to support the decking.

Waste factor: The amount of decking material wasted during the process.

An extra 10% or more is added to the total account for cutting mistakes or damages.  

Factors such as deck dimensions, load-carrying ability, choice of material, spacing of joists, beams, and decking boards are considered to determine the exact amount of material needed. Here are some Critical elements in a decking calculator include;

Deck measurement: Length and width of the deck surface. These define the total area to be covered by decking material.

Decking material: This defines what decking material shall be used, the board size, and the material required.

Board width: Influences the number of boards needed to support the decking.

Joist spacing: defines the distance between joists for the framing material to support the decking.

Waste factor:The amount of decking material wasted during the process.

An extra 10% or more is added to the total account for cutting mistakes or damages.  

Calculation Process

When designing a decking project, it is vital to determine the exact amount of materials needed, such as decking boards, fasteners, and supports. The first step in this is to get an accurate amount through material takeoff to ensure that every aspect of the project is considered to avoid overestimating or underestimating the materials. Here are some steps required for the calculation process.

Step 1: Measure the Deck Area

The first step in the decking calculation process is to measure the area of the deck that needs to be covered. Start by measuring the length and width of your deck using a tape measure. For a rectangular or square deck, the area is calculated by multiplying the length by the width.

Formula:

Area=Length×Width

For example, if your deck is 20 feet long and 10 feet wide, the total area would be

• 20 feet×10 feet=200 square feet
• If your deck has an irregular shape, break it into smaller sections, for example, rectangles or triangles, and calculate the area of each, then sum up the areas to get the total.

Step 2: Decking Material

Decking materials differ in size and type. Some of the most common materials are wood, such as pressure-treated lumber and cedar, and composite decking. Boards are usually 6 inches wide, and lengths vary from 8 to 20 feet. The material you choose will affect the cost and the number of boards you will need.

When Choosing the Material, Consider the Following:

• Durability: Composite materials may last longer but are usually more expensive than wood.
• Aesthetics: Different materials create different looks -from natural wood grains to sleek modern composites.
• Maintenance: Wood requires more upkeep, such as staining, but composites often require less maintenance.

Step 3: Provide for Board Spacing

Decking boards aren’t nailed tight together; there must be an expansion gap between each board for moisture drainage and airflow. Most commonly, that gap is around 1/8 to 1/4 inch.

To fill in the gap, take the difference of the widths.

For example, if you are using 6-inch-wide boards and a gap of 1/8 inch, the number of effective inches is given as follows:

• Effective width=6 inches+18 inch=6.125 inches
• This slight gap alters the count of the boards needed because the gap shrinks the width covered by the board.

Step 4: Count of the Boards

To calculate the number of decking boards you require, divide the total deck area by the area of one board.

Example: Assume the total deck area is 200 square feet, and each board is 6.125 inches wide and 12 feet long (1 foot by 12 feet).

First, calculate the area of one board:

• Area of one board=Board width×Board length=0.51 feet×12 feet=6.12 square feet per board.
• Divide the total deck area by the area of one board:
• Number of boards=200 square feet 6.12 square feet per board≈32.68 
• Since you can’t purchase a fraction of a board, round up to 33 boards.

Step 5: Determine how many joists you will need

Since the joists are spaced 6 inches apart and the deck is 20 feet long, you can calculate the number of joists by dividing the length of the deck by the spacing between the joists.

• Convert the spacing into feet: 16 inches =1.33 feet.
• Number of joints: = Deck length/ joist spacing =20 ft/ 1.33 ft = 15 joist step 

Step 6. Calculate the Number of Beams and Posts

Larger decks contain more structural elements, including beams and posts. Beams are horizontal supports that support the joists, and posts are vertical supports that hold up the beams. The number of beams and posts depends on the size of the deck and the local building codes.

For instance, Assume for simplicity that you will need two parallel beams to the length of the deck:

• You can get around four posts with supporting beams for a standard-sized deck.

Step 7. Add Fasteners and Other Parts

When calculating, this will be able to estimate the number of fasteners, such as screws or nails, required to attach the decking board to the joist. The figures are calculated on how many boards are in the gap between the boards.

Example

• Deck screw: 200-300 screws to attach one decking board
• Stairs: If your deck includes stairs, the decking calculator figures out the amount of material you will need for your stair framing.

Step 8: Allow for Waste

It’s always a good idea to allow some waste—-boards that might get damaged, cut wrong, or just have leftovers. A 10-15% waste factor is typical. For instance, with 33 boards and a 10% waste factor:

• Adjusted number of boards:=33 x 1.1=36.3 Round up to 37 boards to make sure you have enough material.

Step 9: Estimate the Total Material Cost

After you have determined the number of boards and joists, you can estimate the total cost of materials.:

• The cost of decking boards is $5 per board,
• The cost of joists is $10 per joist,
• The total material cost would be:
• Cost of decking boards: = 37×5=185 USD37
• Joists cost: = 15×10=150 USD

In total, the boards and joists would amount to $335. Remember to mention the additional costs for materials like fasteners and sealants, which the deck will need during its installation process.