Update Bookcase with Crown Moldings

Update Bookcase with Crown Moldings


Update a Basic Bookcase with Crown Molding

I have always been a fan of custom built-in bookcases but have been intimated by their price and the skill required to create them. However, about a year ago I enlisted the help of my father and a few other skilled family members to help me transform a few bookcases into a custom entertainment unit. I was thrilled with the results and learned that a little paint and crown molding goes a long way. This knowledge came in handy when I recently purchased some basic "assemble yourself" bookcases for my office and realized after putting the room together that it still felt a little flat and the bookcases looked pretty dull.

desk with bookcase

I decided to dress them up with a little crown molding to give them a more custom built-in feel. Carpentry is NOT my strong suit, so I figured that if I could do this so can you. It took a little time, but I love how they look now…

bookcases with crown molding

Cutting crown molding can be a little mystifying. There is a lot of "cut upside down and backwards" talk that makes your head spin and feel like you should have paid more attention in geometry class. After consulting all the carpentry wizards I knew, I finally figured out a method that worked for me... cutting it flat on a compound miter saw. I even created a little cheat sheet to help you transform your basic bookcase into a custom piece. I'll outline how to simply add crown to a piece (beginner) and how to combine more than one bookcase and add crown (more advanced). Believe it or not, writing this post and trying to explain the process was actually harder than doing it!

You will need:

  • Basic bookcase(s)
  • Crown molding of your choice- measure the linear feet around top of bookcase and add the breadth or height of the crown molding for each outer corner (then add 10% just in case)
  • Additional flat stock molding and lattice if adding more detail (more on this below)
  • Nail gun with compressor
  • Compound Miter Saw
  • Wood glue
  • Wood putty
  • Caulk
  • Sandpaper
  • Paint and primer
  • Tape measure
  • Pencil

Crown Molding 101:

Now before we get started, let’s talk about the four types of cuts we will be doing. They are referred to as outside cuts and inside cuts, and each one will be either a right or left cut depending on which side it is on when it joins. Think of each corner as if it were part of a box. The molding that protrudes toward you would be going on the outside of the box, and the molding that recedes into a corner would be going on the inside of the box. To make this clearer here is a picture:

crown molding mitres

The first thing I recommend doing is drawing out how your crown molding will lay out on your bookcase. Identify what types of cuts you will be making by labeling each section. I abbreviated outer left and outer right as OL and OR below. The area where the molding will abut the wall will get basic straight 90 degree cuts. I also labeled the sections numerically left to right and wrote the widths of the bookcase sections as well. As I cut each section I numbered the back of each piece in pencil so I could easily assemble later.

crown molding sketches

How to Cut Using a Compound Miter Saw:

Each of these four cuts require different settings on a compound miter saw. If you are not familiar with the saw, a compound miter saw has the capability to cut a beveled edge by adjusting the angle of the blade, and/or make miter cuts by adjusting the angle along its base. The straight metal edge along the base that you will be using as a guide is called the fence.

mitre saw

Each of your cuts will require you to adjust the bevel and miter angles accordingly. Most compound miter saws have pre-marked spots to show where to set your blade and base for commonly used cuts of crown molding. My saw is VERY OLD and has them, so seriously...if I'm able to make this happen, anyone can!

miter angles

Here is a cheat sheet for making your cuts. Print it out and keep it next to your saw.

mitre saw diagrams

Once you have your cuts made, you can begin to attach it directly to your bookcases like I did at my desk. These bookcases were a breeze since the molding attached right to the bookcase and no build out was needed. They took less than an hour to do both.

crown molding on bookcase

The pair of bookcases across the room took a bit longer since I had to combine them to make one larger built-in unit and required adding a 1x6 between the two bookcases.

crown molding on two bookcases

I attached mine using hinges so I had a hidden door to store tall items like fabric bolts and wallpaper.

1x6 attached with hinges
hidden door

I also added hooks to the front of the panel that also act as door pulls...

hooks used as door pulls

Since there wasn't much to work with on the top of the bookcase I decide to add a 1x4 around the top to add extra height. I then added a 1 1/4" wide lattice strip to hide the seam and give it more character.

added 1x4

Once that build out was complete, I was finally ready to add the crown.To attach crown molding, run a thin bead of wood glue along the edge where it will be against your bookcase and then carefully match the bottom edge with your first outer or inner corner.

wood glue

It helps to have an extra set of hands here to hold the molding in place and level it as you begin nailing it to the bookcase. Use a nail gun to firmly attach it. I just recently bought this Campbell Hausfeld nail gun and compressor and it is my favorite tool ever. I can't believe I went this long without one!

nailing crown molding

Attach the rest of your molding being sure to glue all edges that will make contact to another surface and match your edges up carefully. If you have small gaps in your seams don't worry, wood putty will fill those. Attach to the bookcase first, and then nail into the corners of the crown.

nailing crown molding mitre

Once it feels securely attached you can take a deep breath and celebrate. The hard part is done!

Now you will need to fill your joints and nail holes with wood putty and run a bead of caulking along the seams. Sand the putty when dry and smooth out any rough edges. This is where you can fix and finesse any areas that seemed a little off or fill any large gaps.

sanding crown molding mitre

Once it is all smooth you can prime and paint. Since my bookcase came in a shade of white I took one of the shelves over to my local True Value where they color matched it for me.

matching paint color

I used their Easy Care Ultra Premium Paint & Primer in One in a satin finish.

finished crown molding
crown molding butting into wall

I love how my office looks now, and this project has made me much more confident. There are so many other trim jobs around my house I can’t wait to tackle. I'm no longer scared of crown molding!

finished bookcases with crown molding

A few last bits of advice...

  • I highly recommend purchasing a little more trim than you think you'll need. I made some practice cuts and a few wrong cuts which resulted in a run to the lumberyard to get more trim. This is why it is so important to follow the golden rule of "measure twice, cut once".
  • I can't stress enough to mark the top edge of your can even mark the bottom too! It gets very confusing as to which edge should be against the fence, so that helps make it obvious. Once you get that down it really is quite easy.

I hope this inspires and helps you to customize that flat boring piece of furniture!

finished bookcases with crown molding

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