Stringer Layout

The stair stringer layout is going to be the most important part of the stair building process. Please pay attention, because each step along the way is going to be critical.

In this example we're going to show you how to lay out a three-step stairway. We will be using a 2 x 12 for the stair stringers and our riser height will be 71/2 inches, with a tread width of 10 inches.

Stair Stringer Questions And Answers

Setting Up The Framing Square

Find a comfortable place to work and it wouldn't be a bad idea to grab yourself a nice drink and make yourself comfortable. If you have saw horses, then it wouldn't be a bad idea to place your 2 x 12 on top of them.

Try to create a nice comfortable working environment, where you won't be bent over, for long periods of time. I like to use 36 inch tall sawhorses.

The next thing you need to do is position your framing square on top of the 2 x 12, with your riser measurement on one side and your stair tread measurement on the other side. Line each side up with the edge of the 2 x 12.

Marking And Laying Out The Stringer

After you have positioned the framing square at either end of the 2 x 12, you can start marking each individual stair tread and riser. After you have marked the first one, move it to the left or right, to mark the next one and continue working your way, down the 2 x 12, until you have marked out enough steps, for your new staircase.

Be careful here, because the front of your stair tread measurement will need to line up with the top of previous stair riser, in order to layout the stair stringer correctly.

Laying Out Bottom Of Stair Stringer

You're going to need to subtract the stair tread width from the bottom of the stair stringer. The reason for this is to lower the entire staircase.

If you didn't subtract the width of the stair tread, from the bottom of the stringer, it will push the entire stairway up and you will have problems with your first and last steps.

You will also need to subtract any additional construction materials that will be installed underneath the stair stringer.

For example, if you're going to use a piece of 2 x 4 treated lumber, to separate your wood stair stringers from the concrete foundation, you will need to subtract the width of the 2 x 4, also.

Top Stair Stringer Connection Layout

The top of the stair stringer can connect in a few ways. However, the structural floor framing and design, of the stairway will determine the type of connection, required.

Stair Ledger Connection

This is where you will nail a 2 x 12, on to a wall and use it to connect your stair stringer to a landing or floor. This is the most common method used by stair builders and if you can use it, you should.

You will need to subtract the thickness of the ledger, from the top tread.

For Example: If you have a 10 inch stair tread and you're going to use a 1 1/2 inch thick, 2 x 12 for your ledger, you will need to subtract 1 1/2 inches from the upper step, leaving you with a 8 1/2 inch stair tread, at the very top of your stair stringer.

Floor Stringer Connection

This is where the last stair tread will actually become part of the finished floor. Using this method will require a little more finesse, because you will need to lay out the floor framing, to match the stair stringer measurements.

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