How to Build a Plywood Bookcase

After several years worth of frustration with the sagging shelves of el-cheapo bookcases crammed full of books, and a limited budget, I decided to take matters into my own hands.  This bookcase is made from 3/4" plywood, 2x4's and a bit of trim. It measures 7 feet tall, 4 feet wide and 1 foot deep.  It is a larger version of one I built for my wife last year (4' x 4' x 1').  It is easily scalable if you want to make it smaller.  If this were a conventional bookshelf with 1" x 12" or 1" x 6" such a wide span for each shelf would sag when fully loaded with books, however since this one has a 2x4 frame under each shelf you can boost the width.

All the wood I used is Pine because its cheaper.  The 2" x 4"s don't really matter on quality just so long as they are straight.  The plywood should be with the least amount of blemish you can find.  The rest of the wood should be nice stuff even if you have to pay a little bit more for "premium" grade pine, it needs to be straight and with the least amount of knots, and with a grain pattern you like.  One last tip, Since this will take a while to put together consider buying it in stages to be easier on the budget ex. buy the 2x4's first, make the joints put that together then buy plywood, cut to size then buy trim...

Materials Needed:

Basic Structure
(2) Full sheets of 8' x 4' x 3/4" Plywood  and 1 piece that measures 14" x  48" 
(6) 12' x 2" x 4" 

Trim
(1) 6' x 1" x 4" (for the bottom) 
(1) 6' x 1" x 6" (for the top)
(1) 6' stick of crown molding your choice
(2) 8' sticks of trim (at least 2" wide) 
(2) 1" x 2"
(4) 1" x 3"
  

Stain:
pre-stain treatment (I used Minwax brand for all of the stain treatment)
stain 
polyacrylic
synthetic brush
sandpaper
tack cloth

Tools:
20" or 24" Crosscut saw
Cordless Drill 
Circular Saw (optional)
Kreg Jig® Mini (can actually be done without this but that means you'll have to be really carefull where the screws go to hide them under the trim)
(48) Kreg brand 2" Coarse self tapping pocket hole screws
(72)  1 1/4" drywall screws
Box of !.5" Finishing nails
Box of 2" drywall screws
1" bench chisel
Rubber Mallet
Spokeshave
Rabbet plane (optional but very handy)
Coping Saw 
Nail Set
Stain able wood putty
Wood glue
Combination Square
Tape Measure
Pencil
Back saw
Miter box
Butcher paper
Scissors
Exacto knife

To help speed things along and help with transportation you might consider having the plywood and 2x4's chopped up at the lumberyard/home center here are the dimensions:

(12) 46.5" length 2x4's
(12) 12" length 2x4's
(1) 4' x 7' for the back of the bookcase
(2) 1' x 7' for the sides of the bookcase
(5) 12" x 46.5" for the shelves 
(1) 48" x 14" plywood  for the top

One word of Caution here.  Most Lumberyards are going to be in a hurry and will not likely be very accurate in their cuts, this can be a big problem later.  I would recommend rounding up the lengths where possible (the 46.5" becomes 48") then cutting them again when you get home to their correct length.  You might even want to ask the employee to measure each piece before cutting, he might grumble but this could save you serious time later.  Its ok if in the end you are less than 1/16" off, any more than that might cause problems.
 

Why 46.5 you may ask? because 46.5 + 0.75 + 0.75 = 48 which will make it line up nicely with the plywood backing.

For this project I used 3 kinds of joinery Half-lap, Screws and Nails.  Each shelf will be composed of a frame topped with plywood.  The frames are (2) 46.5" x 2" x 4" and (2) 12" x 2" x 4".  They are held together by a half-lap joint.  A Half-Lap joint is where half the wood is removed on the bottom of one piece, half the wood is removed on the top piece where they will overlap so that they fit together flush.

        If you haven't already cut the 2"x4"s to length then there should be (12) 46.5" length and (12) 12" lengths.  Hold one of the 12" pieces at a right angle from the 46.5" overlapping it at one end then using a pencil trace a line.  Technically a 2x4 is 1.5 in × 3.5 in so this should be 3.5.  Next using a Combination Square hold it up against the 1.5" side and measure to the halfway mark.  This should be 3/4"  draw this all around where you will be cutting so you can easily see what the waste material should be.  When you are done with the 2 cuts they should look like the pictures below.  The cuts are made with a Back saw.

  After you have finished the cuts, clean up the surface with a rabbet plane or some sandpaper.  If this were a smaller half-lap you could do the entire half-lap with a rabbet plane.  Once you finish all the joints, try putting them together as a dry run to see how well the fit.  If either side (or both sides) need adjustment then plane or sand it down some more till they both fit for all the frames.

Now that all the cuts are finished you need to assemble the frames.  Since you have already checked the fit on all of them this should be easy :-) 

    Put some glue on one (that is too much in the picture by the way) then place the 12" piece on top wiggling it around to try and spread the glue (or you can roll it around with a small paint roller or an old rag to get an even distribution of glue).  Clamp it together and drill some pilot holes, then screw the drywall screws in.  After you put the screws in you can remove the clamp (if you have a limited number of clamps) and move your clamp to the next spot to be glued up.  Repeat this process for all 6 shelves.

This step is optional but if you choose not to do it you will have to be creative on hiding the screws with trim or by painting it (thats how I did the first version of this shelf for my wife's craft room)

Set your combination square to 1 and 1/4"
Set the Kreg Brand Drill bit to 4 and 3/4" from adjustable collar to tip of the drill bit

The Combination square will function as a backstop for the jig to help set the distance from the edge.  Next clamp the jig down.  Drill the hole and then move the jig down to the next hole.  I drilled 4 holes on one 46.5" side and 2 holes on both of the 12" sides for a total of 48 holes.  

Now take one of the frames, put the pocket holes you just drilled on the bottom.  Take one of the pieces of plywood (12" x 46.5") and check to see how it fits on top of the frame.  If it needs any adjusting now is the time to do so.  If its 1/16" or less small its ok.

  After checking the fit, take the plywood off, put some glue on it (spread the glue around for better coverage) and place the plywood on it again (best side up) try to position it so that the front will be flush, because it will be seen more than the back anyway.  If the sides are short then try to split the difference.  Once it is positioned, clamp the plywood down to the frame in all 4 corners. Taking your Finishing nails (1.5")  nail the plywood down with at least 2 nails on the short side and probably 4 or 5 on the long side.  Don't nail it all the way down, stop about 1/8" of an inch above the surface and finish driving it with a nail set so that it is just a little below the surface.  Go back over the nails with stainable wood putty.  Let the whole thing dry as long as the glue bottle says then sand the wood putty spots flat.

    Do this process to 5 of the shelves leave the 6th one bare, it will be the top and we will put it on later, it uses the 48" x 14" piece of plywood.

Apply wood putty if needed (any big cracks or holes) and sand the plywood backing, sides and the tops of the shelves (don't worry about the frame unless you just want to make sure their aren't any loose splinters).  On the backing just sand the part that will be the inside of the bookcase.  The sides will need to be sanded front and back. 

 For this part I moved all the work into the house because my wife suggested it :-)  A word of caution though, if your wife isn't tolerant of wood chips, sawdust, the odor of paint or stain then do all this outside and get some very strong friends to help move it inside when you finish, because it will be VERY heavy.  Even the smaller version I made earlier 48" x 48" x 12" is very heavy.

Lay out the back, sides, top and bottom as they will go together.  Place the top and bottom shelves on their side so they stand up.  Very carefully screw the sides into the top and bottom shelves using the 2 inch wood screws drill straight through the sides into the frame of the shelf (trim will cover this later) making sure that the front of the shelves and the front of the sides are as close to flush as you can make them. Ensure that the top is flush with the top of the sides and that the bottom is flush with the bottom.  

  Carefully position the assembly on top of the backing and put in the special bit for the Kreg wood screws.  Using the pocket holes you drilled earlier screw the back and sides to the shelves.  Turn it up on its side and place some drywall or wood screws straight through and into the frame for extra strength.  Now lay it back down.  Congratulations you now have a coffin err I mean partially assembled shelf.  

  Next you will need to make 4 spacers.   Measure the inside of the case from top of the bottom shelf to the bottom of the top shelf.  Subtract from that number the thickness of a shelf x 4 because there will be 4 shelves between the bottom and top, then divide that number by 5.(because there are 5 gaps between shelves between the top and bottom)

X = distance from bottom of top shelf to top of bottom shelf
Y = thickness of shelf (frame + plywood top)

[X - (Y * 4)] / 5 = spacing between shelves.

For my bookcase I think it came out around 14.5"

You can use this formula to scale down this bookcase if you want.

Once you have the spacer length figured out, cut four spacers out of scrap wood.  Place them on top of the bottom shelf and put the next shelf on top of them.  Make sure the shelf is flush with the sides in the front and screw it together using the pocket holes you drilled earlier.  

For extra support if you are really careful you can screw 2 drywall screws in the sides straight through to the frame but do it so that it will be hidden by the trim (less than 1/2 inch away from the edge).  Also add drywall screws on the back side, be very careful to keep them straight so you don't screw under or over a shelf.  If you have trouble you might try using a chalk line on the back of the case to give a visual indicator of where each frame will be.  The extra screws will help to strengthen the case.

Now just  repeat this step till you get all the shelves in.

Attach the extra big shelf (14" x 48") to the top.  This should be big enough to cover the edge of the plywood on both sides and the back.  If this were a shorter bookshelf and people could actually see the top then this would be important.  

Now we will attach "feet" to the bookshelf.   This is so that the edge of the plywood will not be resting on the floor.  That might damage the plywood.  It is also so that the trim (which is made up of a 1" x 4") will fit.  Don't worry there isn't any joinery involved here except drywall screws.  Just  make (2) 2" x 4" s  41 inches long and the sides should be 14 inches (measure to make sure, just ensure it will be flush with the edges) after cutting the boards to size wood glue and screw them into the frame of the bottom shelf.

 You might need to call a friend for this step, it is really heavy DON'T hurt yourself.

 Now attach most of the trim.  By most I mean the 1x3's go along the sides to cover where the back of the bookcase would show then one on the front side flush with the edge of the plywood.  1x2's on the front of the sides to cover the edge of the plywood on the front.  Measure the distance between the 1x3's on the side and cut the 1x4 to size for the bottom, do the same for the 1x6 for the top.Measure and cut all these attach them all EXCEPT the 1x6.  Just dry fit it to ensure it has a snug fit but not too tight.    Attach them with wood glue and finishing nails.  Remember to countersink them with the nail set.

Measure and cut the Trim for the front and the 1x4 and 1x6.  Go ahead and glue and nail everything (making sure to counter sink the trim nails)  except for the 1x6, just dry fit it.  Make sure its snug but not too tight.

 If you want you can skip this step.  I did this to try and challenge myself.  If you want you can just go on to the next step and either use really big crown molding or instead of crown molding find a nice decorative trim (I used an Ivy leaf trim for the top of the smaller version of this case, it looks very nice IMHO just be sure to do a 45 degree miter cut)

  First position the 1x6 in the shelf as it will be when its finished.  Next reach behind the 1x6 and draw a line against the frame so that you will know where the frame begins (so that you know exactly how much wood you have to work with).   In this one I have exactly 3.5" to work with.  After you draw on the backside of your board go get some butcher paper.  Draw out the board and the line so that it is a perfect representation of the board.  

Draft out your design on some scrap paper.

Now do the numbers.  In my case the first notch is 1", 2nd notch 12", halfway mark (not a notch) is 23.25", 3rd notch 34.5" and 4th notch 45.5"  Yes I know its not exactly even but its pretty darn close, and it looks nice :-p

  Locate and place a dot for each notch.  Next figure out where the highest point on each arch will be and place a dot there.  Then very carefully free hand the arch.  After you draw it out and are happy with it (if your not happy thats why they invented erasers), cut out the paper template with scissors and an exacto knife.  Next pin the template down on the 1x6 and carefully trace the edge of the template onto the wood.  Remove the template, retrace it if its not dark enough.

  Clamp the board into a vise upside down so you can cut out the bulk of the waste with a coping saw.  This part should be performed with extra patience.  Haste makes waste.  After cutting out most of the waste leaving just about 1/8" go back on the edges with a 1" bench chisel and hammer.  After the edges are finished you can either continue on with the chisel if you don't have a spokeshave or you can use the spokeshave.  I must confess I have not used a spokeshave prior to this but I found it to be very enjoyable.  It leaves a very smooth result and handles these curves wonderfully!  If you don't have a spokeshave get one :-)

Attach the decorative trim you just made (try to place the nails were they will get covered by the crown molding).

  Miter cut the crown molding at a 45 degree angle.  Measure out the side, place a mark in pencil on the crown molding of where the Inner dimension should be.  Line that up in the miter box.   One tip here I wish I would have known... take some scrap wood and cut a few small 45 degree miter cuts to fit against the crown molding and make it more square it is very difficult to clamp a slanted piece of wood while cutting it.  Take your scrap wood, one on top and one on bottom, and tape it (masking tape)  around , then clamp the whole assembly to the miter box.  This should help cutting the 45 degree angles.

Make sure all the trim nails are counter sunk.  Go back over them all with stainable wood putty, allow it to dry then sand it down.  Sand the whole bookcase, if its really rough start with a course sandpaper like 60 grit and work up to 220 so its nice and smooth, no splinters etc.  Remove all the dust and then go over it again with tack cloth just to be sure. 

Apply a Pre-stain wash.  This will help the whole thing come out more uniform, no blotching and more even coverage.  Allow the Pre-stain wash to dry then apply the first coat of stain.  Be very carefull not to let it drip.  I chose a water based stain because its easier to clean up and very easy to work with.  Allow the first coat of stain to dry for three hours then lightly sand (just lightly brush the "Between coat finishing pad" over the entire project.

Go over the whole project with tack cloth.  If it looks like it needs another coat of stain to make it darker then go ahead and do so, allow it to dry, use the finishing pad again and tack cloth again.

 After using the finishing pad and tack cloth apply the first coat of Polyacrylic carefully.  Drips show up so be careful.  I found it handy to keep a paper towel in one hand in case I noticed a bit of drip, and a task light of some kind to let you see the reflection of the clear coat to see what all you have covered.

Allow the first coat to dry per the can's instructions, sand lightly with the finishing pad, tack cloth the whole thing then apply the second coat.

Allow the second coat to dry then sand lightly with polyacrylic, wipe the tack cloth over it again, and apply the final coat.

Step back and enjoy.  After its fully cured fill it up with some good reading material :-)