In addition to the shelves, which are currently a little hard to access, we are going to be making and installing a rolling ladder. That, however, is another instructable for another time.
Step 1: Tools and Materials
Miter saw (Chop saw)
Drill - both for drilling holes and driving screws
Square or Straightedge (a ruler is fine)
Countersink drill bit, #8 (to match the screws)
Melamine shelving, 3/4" x 11 3/4" x 97"
MDF board, primed, 1" x 2"
Screws, #8 x 1"
Screws, 2" drywall
Liquid nails (or other construction adhesive)
Caulk, interior grade
Paint, interior grade
I was able to find everything I needed in one trip to my local home improvement store. I have occasionally had trouble finding a source for the primed MDF boards, but there are a lot of alternatives out there. Base moulding works great (used upside down), or 1 x 2 pine boards, or even 2" strips of 3/4 plywood would be fine, really, whatever you like.
I also spent a little time clearing off all our stuff and cleaning the ledge off. It was pretty dusty up there!
Step 2: Layout
I don't want the shelves to sag, so I planned them to be 30" to 32" wide.
I tried to keep my shelves to one of three heights: 7", 10", or 14". The 7" shelves work great for paperback books, and the 10" shelves are great for most of our hardbacks. The 14" shelves were made for a few of our taller books like yearbooks, dictionaries, a few photography and artwork books, binders, etc.
I ended up having two 14" tall shelves that are both 32" long, and it is WAY more than we needed. If we could do it again, the majority would be 10" because they have been the most versatile, and the first to fill up. We could really use a few more. While the goal was for 7", 10", or 14" shelves, I did make a few adjustments to that to take the overall aesthetic into account, so there are a few "odd" sizes mixed in.
Step 3: Cut Your Support Strips
I chose for the support along the wall to be full length, so the side pieces each need to be 3/4" shorter than the depth of the shelf they support.
Step 4: Install Vertical Dividers
Once you have a good horizontal measurement, take the shelf down and install the shelf supports which will control the height between shelves. Start by carefully laying out and marking lines where the supports should be attached. If you aren't careful, you could end up with shelves that aren't level, so measure twice, install once.
Set your countersink drill bit to match the length of your screws. Lay your support strip on the melamine shelf, line it up with the layout marks, and drill two holes. I placed one near the front and one near the back, but exact placement is not critical here, and finally, drive your screws tight. Be careful not to counter sink too deep or drive your screws too far and have a screw stick through on the other side.
Put the vertical divider back in place and use the side supports to help hold the long back supports in place while you fix them to the wall. I use a small bead of construction adhesive along the back, then screw into any studs you can find.
To install the dividers may take a little patience. Make sure you go back and line up with the dry fit marks (or your shelves won't fit), and set the dividers in place. Put a thin bead of construction adhesive on the back edge of the divider, where it will meet the wall, and use shims to get the dividers to sit perfectly vertical. This is important so that your shelves don't slope from front to back.
The dividers should not move very much, but they are not really well fixed in place just yet. They won't be super stable until you get the shelves set in place, so be gentle as you work with them.
Step 5: Shelf Installation
Place a shelf on top of the supports, then countersink and screw it down tight. You could put a small bead of adhesive under the shelf, but I don't think it makes a big difference, and I didn't do this to my shelves
Step 6: Finish Work
Once the putty is smooth and sanded, caulking is in order. Put a thin bead anywhere you have one surface meeting another. shelf to divider, shelf to wall, divider to wall, etc.... Also run a bead at the bottom and top of the vertical dividers where they meet the ceiling or the base they are sitting on, and don't forget under the shelves.
Again, any place where you have different surfaces meeting each other, you want a bead of caulk to ease the transition. You can use a caulking tool to smooth out your bead, but I prefer to use my finger as I have a little more control. Just run your finger along the bead, squishing the caulk into the gap between surfaces and leaving a uniform concave caulk surface behind. The most challenging spots are inside corners where you have three caulk lines converging.
You can see from the pictures that I actually putty and caulk as I go, not wait until the end, but either way works just fine.