Installing Crown Molding

Basic crown molding cuts include making coped corner joints, outside miter cuts, splice (scarf) joints, and square cuts. Without some initial practice on scrap pieces of crown molding you may find yourself wasting a significant amount of crown molding material, and money, on poorly crafted cuts and crown molding joints.

Also, when it comes to learning how to cut crown molding, it is important to understand how to orientate the crown molding in the miter saw so that the resulting finished cut is the way you want it to look on the wall.

Unlike installing baseboard trim, or door and window casing trim, you need to position the crown molding differently on the miter saw. When cutting crown molding, it is best to position the crown molding stock upside down and backwards on the saw, otherwise a special jig is required to hold it in proper position.

Start with a Simple Crown Molding Project Most first time crown molding installation do-it-yourself homeowners are led to believe that installing crown molding is similar to installing baseboard trim. Unfortunately this is not true. Installing crown molding is significantly more complicated due to the fact that it has a third dimension, length, width, and depth (how far it penetrates outward from the wall). If you look carefully at the backside of a length of crown molding, you will notice that it has angled faces at the top and bottom.

These angled faces help to create that third dimension. Most crown molding sits on the wall at a 35o angle to the ceiling. It is these angled faces that enable the crown molding to penetrate outwards from the wall and ceiling to create that ornate, finish carpentry look and texture. It is also these angled faces that are the crown molding nailing points, as they are the only crown molding surfaces that actually come in contact with the wall and ceiling. You can observe this yourself by holding up a scrap piece of crown molding along a section of wall and ceiling.

Installing crown molding can also be complimented by installing additional accent pieces above and below the crown molding material. This is known as an under board. Under boards give the appearance a wider finish. Consequently for a first time crown molding project it is best to keep it simple and stick with the basic single layer of basic crown molding stock.

Measuring for and Selecting Crown Molding As with most carpentry projects it is important to purchase sufficient and quality material. The first step in this process is measuring the length of walls that are associated with your crown molding project. It is best to draw up a small sketch of the room with the wall lengths recorded, and numbered. As you select the crown molding stock you can number it to coordinate with your sketch. This will help in selecting the right lengths of material for the project and to minimize crown molding scraps. Always add at least ten percent more than the total measured length, and more if there is a lot of detail in your project to compensate for waste.

When selecting crown molding inspect it for dents, dings, and warping. The last thing you want to do is attempt to install an inferior piece of crown molding, as this will result in significant installation difficulty and a less than desirable finished look.

If you are using solid wood crown molding it is also wise to let the wood rest for 48-72 hours before installing to allow it to acclimate to the room temperature and humidity levels. Although crown molding is available in a variety of composite materials it is not recommended for use by the homeowner. It is more difficult to work with and usually requires special tools.

Installing Crown Molding Basics

When installing crown molding it is best to start by installing a piece that is square-cut on both ends.

After installing the first piece the next subsequent piece installed will typically have a square-cut end and a mitered or coped end. It is best to make the coped cut or mitered cut first, followed by the square-cut. This allows the more intricate coped cut or mitered cut to be tested, and maybe even be redone, prior to making the final square-cut which will determine the finished length of the section of crown molding.

On some pieces one end may need to be coped, and the other end mitered to make an outside corner. Again, it is best to make the coped cut first, and before the final measurement is taken, to avoid a short piece that will not fit properly. After the cope cut is made satisfactory then make the mitered cut.

In some cases, the final crown molding piece installed may require coping on both ends. If at all possible try to make this piece the shortest length in case you incorrectly or improperly make a coped cut. It will help to save on scrap material costs in the event you need to make another attempt on this section of crown molding. You can avoid altogether having to cope both ends of one section by working in a direction such that the last piece to be installed is an outside corner section.

When installing crown molding it is important to nail it to the wall studs and ceiling joists/ceiling strapping. Make sure you have identified and marked on the walls and ceilings these nail points.

In addition to identifying the nail points on the walls and ceilings, it is important to install the crown molding straight and level along the length of the wall. Use a pencil and level to create straight lines along the length of the wall for the base of the crown molding, e.g. 4 inches, to rest upon. Alternatively you can create a chalk line, however chalk lines usually leave stains that are difficult to clean.

Finally, when fastening the crown molding to walls use a finish nail gun with at least two inch nails. Splice joints should be nailed at the splice point using either a finish nail gun or a brad bun. If it is necessary to splice molding pieces insure that the splice lines fall on a nail point (stud) on the wall. Also, apply wood glue to all joints before nailing the crown molding pieces to the wall.