Built in bookshelves in a home library
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Built-In Bookshelves-Library Build: Part 1

A labor of love. That’s what this library build has been. Let me tell you, doing my first real “build” of anything and choosing to tackle an entire room of built-in bookshelves was way more ambitious than I knew. I definitely bit off more than (I thought) I could chew, but it was a sink or swim situation and it 100% paid off!

I started brainstorming how to make the library happen in November and got to work the week before Thanksgiving. The goal was to finish before we left for Christmas at my family’s house mid December. L.O.L! Some people say starting is the hardest part, so at least we had that going for us! But here we are, seven months later, with a gorgeous library of built in bookshelves. And I am SO PROUD because I built the whole thing myself!

There were lots of roadblocks along the way due to lack of knowledge but I learned so much on this project. I went from being nervous about using a drill, to learning how to use multiple types of power saws, multi-tools, jigsaws, and nail guns. Let me show you how I did it so you can do it too!

Getting Started With Your Built-In Bookshelves

In hindsight, I built many parts of this library completely out of order, so I am going to show you how I should have done it and hopefully save you some frustration, time and resources.

Built in bookshelves with plants, books and decor

Something I realized when I started Where We Gather is not just that I love to find deals, but that I love giving things a second life. So much gets sent to the dump in perfect condition, while someone else down the street is simultaneously ordering the exact same thing online. I wanted to start my built-in bookshelves off with pre fab bookcases, and the Ikea Billy Bookcase seemed like the perfect option. All of my Billy Bookcases were from Facebook Marketplace for a literal fraction of the price ($180 total!). The only thing I needed to order from Ikea was one cabinet door and the extension shelves to add to the top for additional height.

Step One – Make a Plan

So let’s get building. The obvious first step is to figure out what your design will be and keep an eye out for Billy Bookcases if you are getting them used, or go ahead and place your order with Ikea if you are purchasing new. How tall are your ceilings? Will you need to purchase extensions? Are you doing any custom work like an over the window shelf or angled bookcases? In this post, we are not covering customizations, but that doesn’t mean you can’t create them!

Step Two – Baseboard Removal and Riser Placement

Next, remove baseboards and add risers where the built-in bookshelves will be. This is essential for a built-in look. Set your baseboards aside and hopefully you can use them again later depending on their height. Build riser(s) from scrap wood, like 2×4’s, that fit the dimensions of the base of the bookcases. I recommend one long riser for stability instead of individual risers for each bookcase. These risers will do two things: 1) allow you to place the baseboards in front and cover that pesky gap at the front of the Billy Bookcase, and 2) get your bookcases closer to the ceiling!

Step Three – Bookcase Prep

Hopefully you have acquired or purchased your bookcases now! Build those bad boys if you got them new, keeping the doors detached until later. Now it’s time to decide where you want the movable shelves placed so that you can fill all of the unused peg holes with spackle. I left the holes in the lower cabinet portion unplugged, knowing that I may want to move those shelves up and down later. No one will see these holes, so it is entirely up to you. Once the spackle dries, sand it down so the surface is completely smooth to the touch.

bookshelf peg holes being sanded

Step Four – Bookcase Placement

Now that your bookcases are prepped and ready, bring them into the space and place them on your risers. Are there any outlets you need to account for? I used a jigsaw to cut a hole for the wall outlet in my bookcase and got the placement wrong…twice! My dad says, “measure twice, cut once,” but that apparently wasn’t enough for me! Measure, once, twice, THREE TIMES if you have to! Remove the outlet covers and, once you have your hole cut and everything matches up, unscrew the outlet so you can pull it through the hole, where you will secure it to the inside of the bookcase.

Once your placement is set to go, attach your shelves to studs in the wall with the provided L brackets. If you haven’t already assembled your extension shelves, do that now and add them to the top of each bookcase.

"L" brackets attached to the wall

If your bookcases are butted up to a wall, skip the following, but if the side is exposed, you may want to consider adding a thin board, the dimensions of the bookcase, from floor to ceiling. I wanted the exposed side of my bookcase to be smooth, solid wood, and I was much happier with the outcome after I added a piece of birch wood.

I used this nail gun and it made everything so easy! Make sure that your nails are short enough that they won’t come out the other side of your bookcase.

lumber being cut in store
Tip: Large pieces of lumber can be cut down for you when you purchase at Lowe’s or Home Depot

Step Five – Adding Baseboards and Trim

Next, replace the baseboard around your built-in bookshelves. This is when you can really start to see everything come together! I recommend cutting your corners on a 45 degree angle, so that they meet almost seamlessly. Just learning how to create angled cuts myself, I didn’t do this, but I totally would now that I’m more comfortable! I used my nail gun to attach the baseboards and used 2 inch nails from this point forward on everything.

bookshleves with trim

Trimming out the shelves is next. Add nice quality 1×2’s to all of the shelves and you will start to see all your hard work come together! Cut the trim vertically, the length from baseboard to ceiling for all of the seams of your built-in bookshelves. Once you have attached these with your nail gun, do the same across the front of each shelf.

Trimming out the very top of the bookcase and the shelves inside the cabinets is optional. One will be covered by crown molding and the other by cabinet doors. But be sure to add trim where the top of the cabinet doors will be (the bottom-most exposed shelf). Skipping this shelf will leave a large gap between the cabinet door and the shelf. When attaching the trim to the shelves, let the excess of the trim hang below the shelves to give you a smooth surface with no lip.

Step Six – Crown Molding

I’ll be honest. I was really nervous to attempt crown molding. I watched tutorials on how to mark the walls and saw to make sure all the inside and outside cuts lined up, but with the current price of lumber (and our expensive taste in dental floss crown molding – $50 per 8′ piece!), we couldn’t really afford to make mistakes. That said, I decided to create “cheat” crown molding and I am so happy with how it turned out! I used 1×4’s for the first layer, and then bought our choice of “decorative trim” (not crown molding) to add as a second layer. The difference between “trim” and “molding” (aside from $$$) is that trim sits flat against the wall and molding is angled and only touches at the outermost ceiling and wall contact points.

Built in bookshleves and couch

There was still a lot of trial and error (*read “guessing”*) for the strange angles I encountered as I trimmed out the entire room. But if you aren’t doing more than a straight wall of built-in bookshelves or all 90 degree angles, it will be easy-peasy.

For 90 degree angles, cut your wood at 45 degrees. Think through your measurements before you cut. Inside corners will be measured to the longest edge of your 45 degree angled cut. Outside corners will be measured to the shortest edge of your 45 degree angled cut. If you need to visualize this, press the tips of your pointer fingers together firmly to create a 90 degree angle.

Step Seven – Caulking and Wood Filling

Time to wood fill and caulk everything. And I mean everything. Rule of thumb that I was given:

Wood to wood = wood fill it

Wood fill all of the nail holes, baseboard seams, crown moulding seams, and shelf trim seams. Try not to over fill, a newbie mistake I made. It will create more work for you later when you have to sand it all off.

Wood to wood = wood fill it

Wood fill all of the nail holes, baseboard seams, crown molding seams, and shelf trim seams. Try not to over fill, a newbie mistake I made. It will create more work for you later when you have to sand it all off.

Wood or other material to other material = caulk it

Caulk aaalllll of the seams of your Billy Bookcases. It will pay off, I promise. This is a seemingly inconsequential detail that will make all the difference in creating a true built-in and seamless look. What does “all” mean? Caulk all the way around each shelf; all four sides – the front side being where the shelf meets the trim. Since you will see the taller shelves from below, this means you need to do this above and below each shelf. Next, caulk where the baseboards and crown molding meet the floor and the ceiling.

A couple exceptions to my wood fill vs. caulk rule is next. Since I wanted one continuous bead of caulk, I used caulk instead of wood fill where the 1×4 crown molding met the decorative trim – both wood. Conversely, I used wood fill instead of caulk to fill the large gap where the baseboard met the base of the bookcase.

wood shavings

Step Eight – Sand and Clean

This one is another long and tedious task of detail and prep work. I found that unless you are sanding off A LOT of wood filler, (for example, where the baseboards meet the bookcase, or a custom area where you had a large gap to fill) hand sanding works better than an electric tool. I primarily used a sanding block of 120 grit sandpaper. If you are using an electric tool, my multi-tool worked better than an orbital sander because I could decrease the speed.

Move methodically from one side to the other covering top to bottom as you go so that you don’t miss anything. Not only did I sand the wood filled seams and the nail holes, but I also did a quick once over on all of the edges of my trim to soften what felt sharp, unwelcoming and harsh.

Time to clean. Vacuum up as much of the dust and debris as you can and then wipe down everything that you are painting with a tack cloth. This ensures that you aren’t painting saw dust into your built-in bookshelves. If you skip this step, you will likely be very disappointed at the finish of your paint.

Step Nine – Priming and Painting

If you spray, this is a big one, but you are SO CLOSE! We chose to spray to get a nice smooth finish, but it’s not a must by any means. Priming is so important on these Billy Bookcases. Whatever they are made of seems to almost repel paint. They will likely need several coats of primer. Don’t forget to do the doors too! Finally, add a couple coats of paint, being sure to use cabinet paint since this will be a much more high-touch surface than walls. Once dry, add the doors and hardware of your choice.

Built in Bookshelves in home library

Library Complete! Send Books!

That’s what it takes you guys! You can totally do this. It will take longer than you think, like every project, but it is completely attainable and way more affordable (and satisfying!) than hiring out. So whether it is a couple of extra bookcases in your hallway or office, or a full library, know that you can 100% tackle this, even with no experience, like me! No kidding, I feel like I could take on the DIY world after creating this library.

Stay tuned for more on the library where I’ll go into details about creating the picture frame molding on the opposing walls of the library!

In case you missed it, check out another DIY phase 1 makeover that we completed during the library renovation that completely transformed our early 2000’s bathroom.