How many stringers do i need for 8- foot, 7′, 6′, 5′, 4′ and 3′ wide stairs? The number of stringers needed for a set of stairs depends on several factors, including the width of the stairs, the material and thickness of the stringers, and local building codes.

Typically, for residential stairs, you will need one stringer on each side of the staircase for every 16 inches of stair width. So, for your specific widths:

1. 8-foot wide stairs: You would need 7 stringers (8 feet = 96 inches, 96÷16 +1 = 7).

2. 7-foot wide stairs: You would need 6 stringers (7 feet = 84 inches, 84÷16 +1 = 6).

3. 6-foot wide stairs: You would need 6 stringers (6 feet = 72 inches, 72÷16 +1 = 6).

4. 5-foot wide stairs: You would need 5 stringers (5 feet = 60 inches, 60÷16 +1 = 5).

5. 4-foot wide stairs: You would need 4 stringers (4 feet = 48 inches, 48÷16 +1 = 4).

6. 3-foot wide stairs: You would need 3 stringers (3 feet = 36 inches, 36÷16 +1 = 3).

Staircase construction is the important part of any building. There is a lot of design and variety of construction material are available in formation of staircase. In today Technology staircase are made of RCC concrete steel and wood. We use the staircase for go up the one floor to upper floor of building. It has many components such as steps, rise, run, waist slab, landing, flight, rails and stringers.

Stringer is the vertical support or structure member that run along centre and each side of staircase. The riser (vertical height) and tread or going or horizontal distance fix into the stringer. Different stringer can combine with different types of stairs tread to provide and almost endless combination of different types of design structure. Stringer are made of different material such as reinforced concrete, steel and wood. Wood stringers come in different types of wood includes – maple, oak and walnut. Wood stairs and steel stringer are popularly used in staircase in homes in industrial Area, factory, business and outdoor application.

Stair stringer made of variety of material and style and smooth finish that can contribute to the look and functionality of the staircase. The best material for a stair stringer depend on the the functionality of staircase and the desired look. Steel and Aluminium and other various types of wood common material used for stair stringer design. When when you locate on either side of a staircase the inner stringer is located against the wall and Outer is stringer is on the side of staircase open to view.

In this article we know about how many stringers do i need for 8- foot, 7′, 6′, 5′, 4′ and 3′ wide stairs. The number of stair stringer you need is depend on the width of the staircase, tread material and thickness of stringer which you used. Generally two stringer are spaced at 18 inches in case of 3 feet or 36 inches wide stairs and 16 inches spaced from centre to centre which are more than 36 inches wide.

**Stair Stringer Spacing**

The spacing between stair stringers depends on the type of stairs and local building codes. Typically, a common spacing is around 16 inches (40 cm) on center for residential stairs

Two stringer are spaced no more than 16 inches apart from centre to centre which are more than 36 inches wide stair and if stair is 36 inches wide, you need to space the stringer at 18″ OC.

**How many stringers do i need for 8- foot, 7′, 6′, 5′, 4′ and 3′ wide stairs**

It is common in the construction industry for roof rafters, floor joist and stairs stringer to be placed 16 inches on centre. Generally stringer can be spaced no more than 18 inches on centre for 3- foot wide stairs and 16 inches spaced from centre to centre which are more than 3 feet or 36 inches wide. So a 3 foot wide staircase need at least 3 stringers and 3 feet 6 inches wide need 4 stringers.

To calculate or figure out number of stringer in staircase, divide the width of stair by 16 inches, then result is add with 1, that resulting figure will give you required number of stringers in staircase which you will need. For example, suppose a staircase is 4 foot or 48 inches wide, then number of stringers in four foot wide staircase = 48/16 +1 = 4, thus you will need 4 stringer for 4 foot wide stairs.

Stair stringer spacing should be no more than 16 inches spaced from centre to centre which are more than 3 feet or 36 inches wide used for 2×6 or 2×12 treads.

**How many stringers do I need for 3- foot wide stairs**

As per thumb Rule, for a 3 foot (36 inches) wide staircase or stairs or stairways you would need at least **3 2×12 sized stringers **spaced 18 inches from the centre. A typical 36″ wide staircase requires 3** 2×12 sized stringers** spaced 18″ apart on center.

Mathematical calculation and formula is such that number of stringers for 3 feet wide stairs = 36/18 +1 = 3. Thus you will need atleast 3 stringers for 3 feet wide stairs/ staircase/ stairways.

**How many stringers do I need for 3- feet 6 inches wide stairs**

As per thumb Rule, for a 3.5 foot or 42 inch wide stairs (staircase or stairways) you would need at least **4 2×12 sized stringers** spaced 16″ from the centre. A typical 42″ wide staircase requires **4 2×12 sized stringers** spaced 16″ apart on center.

Mathematical calculation and formula is such that number of stringers for 3 foot 6 inches wide stairs = 42/16 +1 = 3.625, round it equal to 4. Thus you will need atleast 4 stringers for a 3 foot 6 inches or 42 inches wide stairs/ staircase/ stairways.

**How many stringers do I need for 4 – foot or 48 inches wide stairs**

As per thumb Rule, for a 4 foot or 48 inch wide stairs (staircase or stairways) you would need at least **4 2×12 sized stringers** spaced 16 inches from the center. A typical 48″ wide staircase requires **4 2×12 sized stringers** spaced 16″ apart on center.

Mathematical calculation and formula is such that number of stringers for a 4 foot or 48 inches wide stairs = 48/16 +1 = 4. Thus you will need atleast 4 stringers for a 4 foot or 48 inches wide stairs/ staircase/ stairways.

**How many stringers do I need for 5 – foot or 60 inches wide stairs**

As per thumb Rule, for a 5 foot or 60 inch wide staircase or stairs or stairways you would need at least **5 2×12 stringers** which are spaced 16 inches from the center. A typical 60″ wide staircase requires 5** 2×12 sized stringers** spaced 16″ apart on center.

Mathematical calculation and formula is such that number of stringers for 5 foot or 60 inches wide stairs = 60/16 +1 = 4.75, round it 5. Thus you will need atleast 5 stringers for a 5 foot or 60 inches wide stairs/ staircase/ stairways.

**How many stringers do I need for a 6 foot or 72 inches wide stairs**

As per thumb Rule, for a 6 foot or 72 inch wide staircase or stairs or stairways you would need at least **6 2×12 stringers** which are spaced 16 inches from the center. A typical 72″ wide staircase requires 6** 2×12 sized stringers** spaced 16″ apart on center.

Mathematical calculation and formula is such that number of stringers for a 6 foot or 72 inches wide stairs = 72/16 +1 = 5.5, round it 6. Thus you will need atleast 6 stringers for a 6 foot or 72 inches wide stairs/ staircase/ stairways.

**How many stringers do I need for a 7 foot or 84 inches wide stairs**

As per thumb Rule, for a 7 foot or 84 inch wide staircase or stairs or stairways you would need atleast 7 2×12 stringers spaced 16 inches from the center. A typical 84″ wide staircase requires 7** 2×12 sized stringers** spaced 16″ apart on center.

Mathematical calculation and formula is such that number of stringers for a 7 foot or 84 inches wide stairs = 84/16 +1 = 6.25, round it 7. Thus you will need atleast 7 stringers for a 7 foot or 84 inches wide stairs/ staircase/ stairways.

**How many stringers do I need for a 8 foot or 96 inches wide stairs**

As per thumb Rule, for an 8 foot or 96 inch wide staircase or stairs or stairways you would need at least 7 2×12 stringers spaced 16 inches from the centre. A typical 96″ wide staircase requires 7** 2×12 sized stringers** spaced 16″ apart on center.

Mathematical calculation and formula is such that number of stringers for a 8 foot or 96 inches wide stairs = 96/16 +1 = 7. Thus you will need atleast 7 stringers for a 8 foot or 96 inches wide stairs/ staircase/ stairways.

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**How many stringers do I need for 30 inches wide stairs**

As per thumb Rule, generally for a 30 inch wide staircase or stairs or stairways you would need at least **3 2×12 stringers **spaced 18 inches from the centre. A typical 30″ wide staircase requires 3** 2×12 sized stringers** spaced 16″ apart on center.

Mathematical calculation and formula is such that number of stringers for 30 inches wide stairs = 30/18 +1 = 2.66, round it 3. Thus you will need atleast 3 stringers for 30 inches wide stairs/ staircase/ stairways.

**How many stringers do I need for 32 inches wide stairs**

As per general experience and thumb Rule, generally for 32 inches wide staircase or stairs or stairways you would need at least **3 2×12 stringers** which are spaced 18 inches from centre. Mathematical calculation and formula is such that number of stringers for 32 inches wide stairs = 32/18 +1 = 2.77, round it 3. Thus you will need atleast 3 stringers for 32 inches wide stairs/ staircase/ stairways.

**How many stringers do I need for 40 inches wide stairs**:-

As per general experience and thumb Rule, generally for 40 inches wide staircase or stairs or stairways you needed at **least 3 2×12 stringers** which are spaced 16 inches from centre. Mathematical calculation and formula is such that number of stringers for 40 inches wide stairs = 40/18 +1 = 3.5, round it 4. Thus you will need atleast 4 stringers for 40 inches wide stairs/ staircase/ stairways.

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**Conclusion**:-

As per thumb rule, for a 8 foot wide stairs or staircase, you will need at least 7 stringers which are spaced 16 inches from centre, for a 7 foot wide – 7 stringers, for a 6 foot wide – 6 stringers, for a 5 foot wide – 5 stringers, for a 4 foot wide – 4 stringers & for a 3 foot wide stairs you needed 3 stringers.