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DIY Installing Dentil Moulding

Construction How-To, Finish Carpentry, Mantels. Trim, Molding, Trim Carpentry April 6, 2011 admin


By Matt Weber

 

Crown Dentil Moulding adds depth and character to a room.

 

 

Dentil moulding can make your millwork smile. Like a row of perfectly spaced pearly whites, dentil moulding is a series of repeating rectangular blocks that adds depth and character to millwork such as fascia trim and crown profiles. This style of moulding has been popular for centuries, and traditional installation was a time-consuming and labor-intensive process that required combining all the individual pieces.

Today, homeowners have a few different options when considering dentil moulding (also spelled dentil molding). For a custom look, ambitious installers can still combine various moulding profiles with a strip of dentil trim to create elaborate built-up cornice moulding. With this type of multi-layered trim, the various profiles are installed in laps around the room until all the pieces are in place.

The second and more common option is to purchase the trim with the dentil moulding preattached to the profile. In other words, the manufacturer is assembling the pieces, but you’ll be expected to pay for the service. Crown dentil moulding made from wood is commonly available at most home stores, and for stain-grade profiles where the woodgrain will be visible, this is the most user-friendly option although great skill is still required to achieve perfectly mitered and coped corner joints.

Preassembled wooden stain-grade moulding saves time and labor when homeowners prefer visible woodgrain.

Preassembled wooden stain-grade moulding saves time and labor when homeowners prefer visible woodgrain.

For paint-grade projects, we suggest a third option—synthetic moulding. You can purchase single-piece polyurethane foam or vinyl moulding, which are less expensive, weigh less and resist shrinkage, peeling and other problems associated with built-up moulding. Urethane trim manufacturers offer a variety of sizes and styles of dentil moulding. Plus, with paint-grade projects, minor errors in the installation can be repaired with caulk and painted over. This article details a crown dentil moulding installation using urethane trim manufactured by Fypon.

Tools Required

Safety Glasses
Tape Measure
Hammer or Pneumatic Nailer
Nail Countersink
Corrosion-resistant Finishing Nails
Caulk Gun
Polyurethane Construction Adhesive
Caulk or Wood Filler
Sandpaper
Pencil
Latex or Oil Base Paint
Miter Saw or Hand Saw and Miter Box

 

Prep Steps

As with any crown moulding installation, measure the perimeter of each room and determine how many linear feet of moulding you will need. When ordering, specify a few extra inches of moulding for each corner to compensate for any errors as well as the waste pieces left from the miter cuts. Fypon’s moulding strips are available in lengths up to 16 feet, which, for most applications, allows you to run a single, uninterrupted strip from one corner of the room to the other.

I recommend pre-painting dentil moulding with a sprayer to avoid brush-painting each individual dentil block.

I recommend pre-painting dentil moulding with a sprayer to avoid brush-painting each individual dentil block.

Rather than painting the moulding after installation, which requires carefully masking off the wall and brushing each little “tooth” of the dentil while standing on a stepladder, I recommend spray-painting the moulding prior to hanging it with a HVLP sprayer. Plus, the urethane material comes double-primed from the factory, so you can start with a latex or oil-based finish coat in your choice of color.

Use a stud finder to mark the framing locations behind the wallboard, as well as any plumbing, electrical or other obstructions that might affect the installation.

 Mark the location of the wall's stud framing to indicate solid areas for nailing.

Mark the location of the wall’s stud framing to indicate solid areas for nailing.

To create a solid nailing surface on which to hang the moulding, I installed wood blocks along the perimeter of the ceiling. To do this, I measured the angle of the moulding profile using a combination square, and then cut triangular blocks from scrap wood on my table saw to fit behind the moulding. I nailed these blocks every 16 inches onto the wall studs.

I cut the triangular blocks from scrape lumber on a table saw.

Measure the angle of the crown moulding to determine the size of the mounting blocks that will be installed behind the trim.

Measure the angle of the crown moulding to determine the size of the mounting blocks that will be installed behind the trim.

Nail the blocks into the wall studs.

Nail the blocks into the wall studs.