I want to make a series of bookcase out of 1 X 10 cedar. Is it as simple as screwing together four pieces to make the top and sides and then putting plywood on the back annd intermediate shelves in? Is a 1 X 8 too thin to use a router to cut grooves in for the shelves? (I have a router but I’ve never used it) Or is there a better method of supporting shelves? I’d rather not have too many screw holes showing on the sides. Will a four foot shelf sag under the weight of books or should I buy 6 foot lengths and then cut them in two for three foot shelfs?
Cutting box joints for the shelves is a PITA unless you’ve done it a lot. Most shelving comes with pre-drilled holes for shelf support pins, which work perfectly. Make sure you drill several pin holes at different heights, so you can adjust the shelves.
IMO, a four foot shelf out of 1" stock (3/4" actual) is not sturdy enough for even a 3’ span. My bookcase shelves are 1-1/4" stock (1" actual) and have not sagged in the 20 years we’ve had them. The bookshelf casing is of 1" material (3/4").
1X10 is fine. Mount standards to hang the shelves on so you can adjust them. You need to reinforce the top and bottom of a basic box frame with something like a 1X4 apron in front. But 4 foot shelves are too wide, if you want a 4 ft. wide bookcase add an upright in the middle or switch the whole thing to thicker lumber.
I love cedar, but even #1 pine should cost less, and will be easier to paint if you want that. If you want the natural cedar try some teak oil for a finish.
Easy way if you don’t have the wood already: buy IKEA “Billy” bookshelf kits.
Easy way if you have wood and want to avoid PITA work: Lay horizontal shelf pieces on cinderblocks or bricks.
Not-too-hard way if you dislike cinderblocks: Screw sides, top, and bottom together, as tall and wide as you wish. Add backing if you want. Cut shelves to fit; secure with steel angle brackets. Expanses over 30 inches will sag; I cut vertical pieces to slide between shelves as supports halfway along a shelf, secured with screws.
Easy way if you’re even lazier than me: Find a bankrupt retail store. Look for EVERYTHING MUST GO! signs.
As for shelf length, you may want to consult the Sagulator.
I’d say 4 feet is probably stretching it unless it’s supporting lightweight paperbacks. But my experience is mostly with particleboard rather than actual wood, and the Sagulator suggests it will be acceptable.
If you are using ply on the back (a good idea since it will keep the bookcase square) then put a screw through the middle of each shelf for additional support, so long as you don’t want them to be adjustable.
I would also suggest ripping strips of the 1x10 to 1 inch or 3/4 inch and gluing them to the bottom of the shelves. Yes you lose an inch 9actually 3/4 inch) of shelf opening, but one strip front and one strip back will probably make your shelves sturdy enough to span 4 feet, and sacrificing the material for 1 shelf will brace 5 others. If you are worried about the front of the shelves looking too thick, put the front bracing back an inch or twofrom flush with the front edge. Plus, now you can cut short grooves in the end of the bracing bracing to accept a short length of dowel as pins for the shelves.
But generally, I agree - 4 feet is probably too long and doesn’t look good, plus makes book management more difficult - books will slide and fall over easier. Better to put a center board vertical and limit your shelving to 2 feet long, max 5 feet wide with center piece and 2.5 foot shelves.
Usually plywood backing is done with finishing nails… It’s just stiffening, not load-bearing. If you want load-bearing, on the back of the plywood put those 1-inch strips and run screws through the stiffening strips, plywood, and back of the shelves. I hope your measuring and aim are better than mine and don’t be off by a bit and have screws showing missing or cracking the shelfs.
So to add - most shelving I’ve seen with adjustable shelves either has specific shelf support hardware (small L brackets that attach tot the upright with a metal pin into a hole) or use dowels as supports. To support points, front and back of shelf ends about an inch in. Groove the shelf a bit for the dowel to rest in, and you ensure the shelf does not slide but do not significantly weaken the shelf. Also, you just drill holes to press-fit the dowels in the upright, thus not significantly weakening the uprights the way a dado cut would do.
you can also buy dedicated hardware to support the ends of shelves which is a set of metal strips with regular holes to hold shelf supports - dado a groove to hold one of these front and back on each side.
Too many options.
The specific application is my collection of vintage to modern juvenile fiction- Nancy Drew, Hardy Boys, Henry and Ramona, etc. So paperbacks and small hardcovers, not huge coffee table books.
I already tried IKEA Billy. They sag even with 3 feet shelves with these relatively light books. I have one of IKEA’s solid wood product, Hemnes, for some larger books in the kitchen, but it has six shelves with no option to add more. I figure i can fit 7 shelves on a 7 foot ceiling height.
The idea for a four foot span was mainly to use a full sheet of plywood and lumber comes pre-cut in four foot lengths. I do have a miter saw to cut longer length. Come to think of it potential sagging aside the proportions might look weird with wide, short shelves.
I particularly like the look of cedar rather than natural or painted pine. I’ve previously finished it with linseed oil and liked the result but also like the look of unfinished cedar. My stepfather made some shelves years ago with 1 X 12 shelves and 2 X 12 end pieces with mitered grooves, but I don’t need it that deep and that thick of cedar is hard to find now (Menards and Home Depot don’t seem to have it).
I don’t care if they’re adjustable unless using an adjustable system is the easiest way to do it.
Upthread, someone suggested using shelf standards and I think using them in a groove will be the easiest way to hang the shelves. (And while right now you don’t think you need to adjust the shelves, it’s nice to have the option for the future.)
And I’m surprised that the IKEA Billy bookcases sagged. Googling, the specifications say that the 31 1/2" shelves can support 66 pounds.
Since you already have the Billys, you might try stiffening the shelves with something like these perforated steel strips on the back edge. Alas, the widest Billy shelves are 80cm (31.5 in), so you’d have to cut a bit off each 36-inch length. The steel strips are deeper than your Billy shelves, but no one will notice if they stick up a couple centimeters behind the bottom of the books.
If you build new ones, an alternative to routering deep grooves for metal shelf standards is to use standard 5mm pins, and just router two notches in the bottom of each shelf end.
Rockler sells a jig to get nicely spaced 5mm holes in your uprights.
They used to have a 2 foot Billy, which I modified by drilling some extra holes. But the bastards dropped that line, leaving only the 3’ (which has trouble supporting the weight of full shelves), and 1’ (Which is ugly and inefficient when trying to fill an 8’ space).
I also got some simple pine custom bookshelves made. The quoted price would have been reasonable, if not for the unbelievable incompetence and untrustworthiness of multiple businesses.
I haven’t weighed my books, but my shelves are full. There is some slight sagging, but the real problem is that the structure isn’t stable, the sides eventually bow and shift. It’s really not designed for full shelves.
If I was putting them in again, I’d not do it again. But if I was, I’d screw in every shelf, instead of the way it’s designed with adjustable shelves.
You don’t need grooves for standards, they can be mounted on the surface, they’re only 1/4" thick.
I suggested grooves because the OP said they have a router they’ve never used and cutting grooves is a perfect way to do so.