Introduction: Secret Room Behind Bookshelf

This bookshelf is an iconic door to a secret room. We have focused on inexpensive and easy construction techniques. However, the build involves three technical challenges:

  • ensuring that the books do not strain the hinges,
  • ensuring that the trim hides the hinges while not preventing the door from opening outwards, and
  • making the latch system ingeniously simple and reliable.

Step 1: Our Motivation

At the end of the hall in our home was a storage room with a (not attractive looking) dilapidated bifold door that never closed properly, and was a nuisance. My daughter, Kaylee (17) and I had often talked about replacing the door with a bookshelf-door. When a "secret spaces" contest came along, we used it as the motivation to get the job done. Pretty much I did the build, and my daughter provided the photography, but I thought it a lovely father/daughter project.

Step 2: Supplies:

The photo is incomplete. The supplies used are:

2 of 12" x 96" laminated pine panels. I find these much nicer to work with than dimension lumber as the lamination makes them more stable. They are very little more expensive than dimensional lumber.

1 of 4 x 8 hardboard, white on one side for the back.

Trim: baseboard trim, and door trim to match the rest of the house.

Hinges: nothing special.

A wheel (not a castor type). The wheel was selected to be not too high so it could be covered by the door trim.

A classic gate latch.

Screws, mostly 1.5", a few 2", some that came with the hardware.

Some small (#8) washers for spacers.

Brads (for my brad nailer.)

Step 3: Figuring Out the Hinge, Trim Issue.

This is the hardest part of the build. I took a piece of the trim, and carved out a slot with my router in my home-made router table. After a few experiments, and lost trim pieces, I got the depth set to make the deepest slot that would not cause the trim to break. I then built out a block on the bookshelf, so that the trim just covered the hinge when it was in the right place on the bookshelf. The depth was not quite enough, so the trim rides the hinge, but the trim just barely conceals the hinge. The fact that it rides on the hinge is of little importance, but it may be the fact that the wood is touching the hinge that gives the door that great classic creaking sound. In any case the door creaks quite nicely even with no books on the shelves.

Step 4: Building the Basic Box

I cut the 12" pine to length for the sides, top and bottom before ripping them to width. When I ripped them to width, I set the table saw to just narrower than the middle of the board, then ripped a sliver off of the other board. The only thing I did with the table saw was ripping things to width, so I never had to reset it, which was great.

I screwed the sides onto the top and bottom, after drilling pilot holes. Calculating the width of the bookshelf was difficult until the hinge issue was figured out. Note that on the hinge side, the top and bottom are not flush. This was laziness on my part, as it is really hard to see. As my miter saw was in my shop, nowhere near the build, I figured I'd take that liberty.

I have really enjoyed this simple joinery of throwing a screw into the end of the laminated pine boards. I have used it quite a lot, and as long as the screw-heads aren't glaringly visible, I found it rather effective, and extremely time-efficient.

Step 5: Mounting the Wheel

I very carefully established the height of the wheel with a piece of the trim as a guide, remembering that the trim had to be up a hair from the floor so it would sweep freely. I adjusted the height with a few washers. I also aimed the wheel a little bit so that it would guide the bookshelf around the curve rather than trying to go straight. I didn't use high precision to figure out this angle. The wheel is not at the center of the base because the floor is a bit uneven. The hardwood goes part-way into the storage room, I had to make sure that the wheel didn't fall off the hardwood when closed.

Step 6: Putting in the Shelves

Figuring out how wide the shelves would be couldn't be determined until the box was built. I made the shelves all identical by crosscutting the 12" panel, then ripping them to width. I made two spacer boards the width I wanted the shelves to be separated by. I built the shelves up one at a time, simply spacing them with these two spacers.

The wheel on the bottom of the box made it impossible for me to stand up the box, so I turned the box upside down. This was great. Now the first board I put in was the upper shelf, and the last was the lower shelf. In each case, I pilot drilled from the inside to the outside so that the screws would enter each shelf very nearly in the middle. I then placed the shelf in place and mounted it with 1.5" screws. I don't know of a quicker and easier way to build shelves, and with the screws hidden behind the trim, why not?

Step 7: Mounting the Bookshelf

To get the bookshelf to sit right while I put the hinges into their final resting place, I built up a stack of books on the hinge side of the bookshelf until the height was just right (it was level, and the trim fit right.) I used my trim scrap as a depth guide and mounted the hinges in place. (Note that I haven't put the back on yet.)

At this point, the bookcase opened and closed quite nicely.

Step 8: Mounting the Trim

I cut the slot in the hinge-side trim with my router table. I then cut an end slot in the top trim piece, because in the corner of the trim, it has the same need for space. After cutting the end slot, I cut the 45.

I placed the hinge-side trim in place first, testing its position so that the door would open without the trim hitting the wall, and so that the trim would (just barely) cover the hinges. I raised it off the floor with the cover of a hard-cover book, just to give it sweep room. The other pieces that need sweeping were measured with the same book.

You will notice that the piece of wall trim just to the right of the hinge trim is not "tight". It needs a slot so that the hinge trim doesn't interfere. This is the biggest "tell" that this is more than a bookshelf. The other tell is the sweep gap for the trim. Pretty small tells, though, I think.

Step 9: The Back

I chose not to put on the back until everything else was in place, then I brad-nailed the back onto the finished bookshelf. If the back goes on earlier, I doubt if you will get it to square to the build quite perfectly. It'll be bad.

The back I chose was hardboard that was finished white on one side. I got my hardware store to cut it slightly oversize both for width and height. It slightly overhangs on the hinge side as well as on the bottom. But you'd need an eagle eye to see it.

Step 10: The Latch

I actually spent a lot of brainstorming time figuring out the latch system. I concluded that having the door open in could be really bad because if something fell, blocking the door, you'd never be able to open it. The resultant system was just so, well, simple.

I chose the location for the latch side so that one of the screws went into one of the shelves. I adjusted the placement of the latch peg with a 1 x 4, and a few washers. It took a bit of fiddling, but with my daughter opening and closing the door for me, while I adjusted things inside, it didn't go half badly.

Step 11: Connecting the Book

The first question was, what book will be the key? I went on Amazon and searched "open the door", when this book "Just Open The Door" showed up, I thought, how, how, obvious. It's perfect for this iconic build.

I drilled a small hole at the shelf-line where I wanted the "key" book to be. I tied two strands of fishing line to the hole that is designed for it on the latch. I ran both strands through the tiny hole.

One of those strands got tied to a paper clip so it can't go back through. This is a safety line. I can just imagine somebody pulling on the book to try to open the door. If the 20 lb fishing line broke, you'd have a dickens of a time opening the door. The safety line may prove priceless.

I drilled a hole in the book, and, with some bother, tied the fishing line to it with the right amount of wiggle room.

Step 12: It Worked!

First try. The latch holds the bookshelf nice and close. The book unlatches it nicely. When you open it slowly you get a great creaking sound. I love it.

When we finally got it full of books, it became very heavy to open. Books are just heavy. There's no way this build would work without the wheel to take the weight.

Bruce Fast
and Kaylee Fast (photographer).

Secret Compartment Challenge

Participated in the
Secret Compartment Challenge