QA

Question: What Size Lumber For Stair Stringer

Are stair stringers 2×10 or 2×12?

It is acceptable and within building code guidelines to use either 2×10 or 2×12 dimensional lumber to create a set of stairs; however, a stair stringer should not be less than 3.5 inches wide at its narrowest point to provide adequate strength for the load the stairs will be supporting.

What size lumber should I use for stair stringers?

Stringers should always be cut from 2x12s. Notching smaller stock doesn’t leave enough wood to safely carry the loads of a stair. When ordering stringers, allow about 14 inches of stringer length for each step. Look for straight stock with as few knots as possible.

Can I use 2×8 for stair stringers?

You should attach 2×6 or 2×8 support framing under the rim flush to the bottom of the stringer. The stairs will hang here. Install a piece of blocking below the rim joist to extend the attachment surface for your stairs stringers. Use a level to mark the top step.

How do I know what size stair stringer I need?

Take the total height of your stairs divided by the number of steps. This will give you the exact height you should cut each rise in your stair stringer boards. You can use the chart below to help convert the decimal you calculate into a fraction you can use to measure out your stringer in inches.

How far can a 2×12 stair stringer span?

A 2×12 stringer has a maximum unsupported span of 6 feet. These stairs (7) are likely to deflect and cause the stringers to either pull loose from the framing or shear along the grain.

Can I use 2×12 for stair treads?

Stair treads may be made of a single 2×12, but are often made of two decking boards or 2x6s. A stringer is a wide board, usually a 2×12, that runs at an angle from the landing pad to the deck framing and supports the treads. The stair treads should be at least 36 inches wide.

How long of a 2×12 do I need for stairs?

We suggest 10.5″ for 2×12 or 2 – 2×6 Treads. Treads may be cut to suit other widths. Either B or C is required.

Are stairs 45 degrees?

For most standard stairs, the stair angle varies between 30 degrees and 45 degrees. Egress stairs have a shallower angle around 30-35 degrees while industrial stairs have steeper angles ranging from 40 to 70 degrees.

What size should deck joists be?

Commonly used joist sizes are 2-by-6, 2-by-8 and 2-by-10. For example, when you space joists 16″ apart — which is standard for residential decks — a deck spanning 9 1/2′ would require 2-by-6 joists, a 13′ deck would need 2-by-8 joists and a 16′ deck calls for 2-by-10 joists.

How do I calculate how many steps I need for stairs?

Determining the Rise You divide the height by 7 inches; if, say, the floor-to-floor distance is 8 feet, 10 inches (or 106 inches), then you’ll need 15 treads (106 divided by 7 equals 15.14). Next, you divide the height by the number of treads (15 into 106), producing the exact tread height (7.06 inches).

How tall is a 5 step stringer?

Stair Stringer-5 step Redwood (Common: 60 in. x 11 in.; Actual: 1.5 in. x 11 in. x 60 in.).

How far apart do stair stringers have to be?

Deck stairs are typically made from 2 x 12 stringers spaced about 12 to 16 inches apart. They rest on a solid foundation and are attached to the deck with hangers. They have risers (also called toe kicks), treads and railings. The stairs should be at least 36 inches wide.

How do I support a stair stringer?

If your stringers are more than 10′ long, we recommend installing a rigid beam at mid-span to add support to the structure. The strength of stair stringers is considerably weakened by the cuts made to create the stair surfaces, and stairs must be.

How high is a 2 step stringer?

Step stringers are cut for 2 In. x 12 In. treads, and have a 7 In. rise.

How much overhang should a stair tread have?

The nosing on treads, believe it or not, has a code minimum and maximum of how far the nosing projects over the next stair. Nosings are required to overhang a minimum of ¾-in. to a maximum of 1-¼-in. Also the maximum nosing radius cannot exceed 9/16 of an inch.

How thick is a stair stringer?

Stair Stringer – 3″ thick. All stair stringers are 11 1/2″ tall. Hardwood stringer boards for free standing open rise staircases are available in any thickness and overall dimensions required.

What is the best rise and run for stairs?

On a main stair, the maximum rise should be no more than 8 1/4 inches and the minimum run should be no less than 9 inches. To determine how many steps, or treads, you need, measure from the top of the finished floor on the lower level to the top of the finished floor on the upper level.

Do stair stringers need support?

Yes, the stringers need to be supported along their length, but they can span a few feet too, depending on 1) the width of the stairs, 2) the number of stringers, and 3) size of riser board. 1) The wider the stair the more load will be transferred to the stringers.

What is the standard stair rise and run?

The OSHA standard for rise and run of stairs is maximum 9.5″ rise and minimum 9.5″ run (tread depth).

What is the best stair riser height?

Rule one says that rise plus run (r+R) should equal 18 inches. Why? That’s what most people find to be a comfortable stride on most stairs. You can cheat a bit up or down, but below 17” and more than 19” will result in steps that require strides either too big or too small for most people.