To determine the size of the board needed to span various distances, you’ll need to consider factors like the type of wood you’re using, the load the board needs to support, and the local building codes and regulations. Common materials for spanning long distances include engineered wood products like laminated veneer lumber (LVL) or glulam beams, as standard dimensional lumber is not suitable for such long spans. Here’s a general guideline for the size of engineered wood beams for the given spans: For example:-For a 20-foot span: You might need an LVL or glulam beam with dimensions like 3.5 inches x 16 inches or 5.25 inches x 14 inches, depending on the load requirements and local codes.

Board is generally made of wood or timber. It is load bearing structure and flexural member of frame structure that supporting the floor joist that vertical transfer all the incoming dead load, live load and self load of roof to the post or column via post- beam joint through development length of structure element to the foundation and finally to the soil.

Size of board generally depending on span between two support and all the load acting on it. Board is a beam structural member subjected to flexural stresses and shear forces . The size of the board (width and depth of beam) are governed by the different type of shear forces and stresses. When the board is subjected to loading the bending moment is developed and the moment carrying capacity of the beam depends mainly on the depth of the beam.

In this article we mainly know about wood board size (depth and width). Many species of wood Douglas fir, southern yellow fine, spruce pine fir, others hardwood of different grade of lumber #1, #2 or #3 are used for beam. Board size are mainly of 2 ply such as 4×8 or 2-2×8, 2-2×10, 2-2×12, 3 ply 6×8 or 2-3×8, 4 ply 8×10 or 4-2×10 and 5 ply 10×12 or (5-2×12) are used.

A wood board is a structural support made from different species and grade of wood wood. They are most commonly used in wood frame structures like small houses, although they can be used in other types of construction as well. Beams are designed to resist bending when stressed by weight or forces like high winds

They are included in structural elements like floors and roofs to distribute the weight of the structure and provide support. Historically, wood was the most common construction material in many regions of the world in US, UK, Canada and solid wood beams were a preferred method of structural support. The type of wood board and size both play a role in how much weight a single wood beam will be able to bear.

Highly dense, close-grained woods of different species tend to be preferred because of their increased strength, as well as resistance to insects and rot. The wood beam can be cut in a solid block, I, or H shape, depending on the needs of construction.

In some cases, multiple pieces of wood are stacked and bound to create a single board. If 2 beam nailed together known as 2 ply beam such as 2-2×10 or 4×10, if 3 beam nailed together known as 3 ply beam such as 3-2×10 or 6×10, if 4 beam nailed together known as 4 ply beam such as 4-2×10 or 8×10 and if 5 beam nailed together known as 5 ply beam such as 5-2×12 or 10×12.

**◆You Can Follow me on Facebook and**

**Subscribe our Youtube Channel**

**What size board do i need to span 20′, 14′, 12′, 10′, and 16 feet**

A rough sawn wood board is one whole piece of lumber cut to size. For deciding wood board size a common rule of thumb used for estimating the depth needed for a wood board is the span/15. The width of the board is commonly 1/3 to 1/2 of the board depth. Deflection under full load should never exceed 1/360 of the total beam’s span.

To figure the what size board do i need, measure the span in feet, multiply by 12 to convert that into inches, then divide the span in inches by 15 to get depth of the board. The width of the board is commonly 1/3 to 1/2 of the board depth. For eg, to span 20 feet, you would need 16 inches depth of board. i.e (20×12)/15 = 16″ depth.

**What size board do i need to span 20 feet**

As per general thumb rule, you would need atleast 4-2×16 or 8×16 size of board to span 20 feet. For a 20-foot spans, the board has to be at least 16 inches in depth and 8″ in width (4-2×16) used for residential building or projects. Thus, a 4 nailed 2×16 or 4-2×16 or 8×16 board made of wood can allow to span 20 feet.

**What size board do i need to span 10 feet**

As per general thumb rule, you would need atleast 3-2×8 or 6×8 size of board to span 10 feet. For a 10-foot spans, the board has to be at least 8 inches in depth and 6″ in width (3-2×8) used for residential building or projects. Thus, a 3 nailed 2×8 or 3-2×8 or 6×8 board made of wood can allow to span 10 feet.

**What size board do i need to span 12 feet**

As per general thumb rule, you would need atleast 3-2×10 or 6×10 size of board to span 12 feet. For a 12-foot spans, the board has to be at least 10 inches in depth and 6″ in width (3-2×10) used for residential building or projects. Thus, a 3 nailed 2×10 or 3-2×10 or 6×10 board made of wood can allow to span 12 feet.

**What size board do i need to span 14 feet**

As per general thumb rule, you would need atleast 3-2×12 or 6×12 size of board to span 14 feet. For a 14-foot spans, the board has to be at least 12 inches in depth and 6″ in width (3-2×12) used for residential building or projects. Thus, a 3 nailed 2×12 or 3-2×12 or 6×12 board made of wood can allow to span 14 feet.

**What size board do i need to span 16 feet**

As per general thumb rule, you would need atleast 3-2×14 or 6×14 size of board to span 16 feet. For a 16-foot spans, the board has to be at least 14 inches in depth and 6″ in width (3-2×14) used for residential building or projects. Thus, a 3 nailed 2×14 or 3-2×14 or 6×14 board made of wood can allow to span 16 feet.

**What size board do i need to span 18 feet**

As per general thumb rule, you would need atleast 3-2×16 or 6×16 size of board to span 18 feet. For a 18-foot spans, the board has to be at least 16 inches in depth and 6″ in width (3-2×16) used for residential building or projects. Thus, a 3 nailed 2×16 or 3-2×16 or 6×16 board made of wood can allow to span 18 feet.

**What size board do i need to span 24 feet**

As per general thumb rule, you would need atleast 4-2×18 or 8×18 size of board to span 24 feet. For a 24-foot spans, the board has to be at least 18 inches in depth and 8″ in width (4-2×18) used for residential building or projects. Thus, a 4 nailed 2×18 or 4-2×18 or 8×18 board made of wood can allow to span 24 feet.

**How many deck boards do i need for a 10×10, 12×12 & 16×16 deck**

**A Board foot | Board feet to square feet | Formula for board feet**

**How many joists do i need for a 10×10, 12×12, 8×10 & 10×12 deck**

**How many 2×6 do i need for a 10×10, 12×12, 8×10 & 10×12 deck**

**How much drywall do i need for 1200 square feet**

**Conclusions:**

For deciding board size a common rule of thumb used for estimating the depth needed for a board is the span/15. The width of the board is commonly 1/3 to 1/2 of the board depth. For eg, you would need atleast 4-2×16 or 8×16 size of board to span 20 feet.