Considering Installing Your Wood Floors Diagonally

I have been working with wood floors for over thirty-five years and I am often asked in which direction the wood flooring should be installed.

One of the options I often suggest is laying the wood floors diagonally. Customers will ask, "Are you serious?"

My response is, "Totally."

Let me first explain some reasons why a diagonal installation is a great idea.

1) Many houses are not square. A wood floor installed parallel with the walls is likely to magnify this flaw.

2) Diagonally installed floors can provide a more unique design using the same amount of materials as parallel installation. If done properly it will not incur any more waste than a parallel install.

3) Common with old fir flooring is the lack of a subfloor. If laying over another wood floor which has been installed without a subfloor and at right angles to the joists, a diagonal installation spans the joists without following the expansion and contraction of the old floor. This will reduce the chance of unwanted spacing between boards.

4) If your house has the joist running one way in one part of the house and at right angles to that direction in another part, a diagonal installation will span the joist regardless of which way the joists run. Having the wood flooring span the joists adds another layer of structural strength to the wood floor in your house. Installation of flooring in the same direction as the joists means you still have only the structural strength of the subfloor. This change in direction of joints often occurs when an addition is added on to the structure.

5) A diagonal installation can make your space appear larger. The diagonal dimension of any room is longer than either the width or the length.

6) Laying the wood floor at an angle can draw the eye to the focal point, such as a fireplace, in a room. For example, attention would easily be drawn to the fireplace instead of remaining at the front door.

7) A diagonally laid floor is unique. I did a diagonal installation in a home in Montana. When the installer from the local flooring store came to do the estimate for laying tile in the entryway, he said he didn't even know flooring could be installed diagonally-he had been doing flooring for over thirty years.

Secrets to successful installation of a diagonal wood floor.

1) Snap a chalkline at the angle you want the flooring to run down the middle of the room. Most common is a forty-five degree angle. You can measure equal distances on the edges of the subfloor if it is plywood or OSB (oriented strand board). You should never install a nail-down wood floor directly over particle board. If your room is shaped in a rectangle you can also choose to snap this line from one corner to another.

2) Take 1"x 2" pine boards and nail them so that they follow this chalk line. The 1" x 2" lumber is easy to bend as you nail it. This creates a straight starting point for your installation. Place the groove of the first boards against this straight "dummy board." Then blind nail those first boards on top of the tongue.

3) Install to the corner. One of the secrets to installing the floor diagonally is to measure the last two boards at the wall together without nailing. Place the board next to the wall with the angle cut first and then slide in the next to last board on each row before nailing. This solves the problem of getting that angle at the wall correctly positioned.

4) Once you have installed the wood floor to the corner come back to the center of the room and carefully remove the "dummy board." You will need splines which are pieces of wood one-quarter inch thick by three-eighths of an inch. You can make these splines out of scrap wood flooring with a table saw. I sometimes make them out of paint stir sticks for five-gallon paint cans.

5) The splines fit in the groove of the first board which was resting against the "dummy board." It should stick out enough to create a tongue. By nailing the spline you have reversed the flooring in the opposite direction. Simply install the flooring to the opposite corner.

Creating this diagonal design will provide an added dimension of character to the room that is likely to surprise and delight not only you, but visitors who will be intrigued by this unique floor.