An old wood straight ladder combined with new or recycled wood becomes a useful, decorative bookshelf with some basic tools and a little know-how. Whether you repurpose a wood ladder from the garage or find an interesting specimen at a flea market or antique mall, you can create a shelving unit with character that purchased shelving units lack. Flex your creativity in choosing wood for the shelves, or simply purchase inexpensive melamine board shelves. The key is to make sure each shelf has the same length, width and thickness and will fit over the rungs of the ladder.
Measure the ladder you'll use for your bookcase. Also measure floor to ceiling the wall where you'll install the book shelf. The height of the ceiling will determine the ladder lengths you'll use for the bookshelf supports. For instance, if you have an old wooden straight ladder that measures 16 feet long, you can saw it in half to create two eight-foot supports. However, if your wall height is less than eight feet or you want a shorter book shelf, you'll have to saw the ladder into two even sections to fit the room height, with a length of ladder left over. A longer wooden ladder, such as 24 feet, could yield supports for two book shelves with six-foot supports, so consider the ladder and wall measurements and how you can make the most of your ladder before you cut.
Saw the ladder into two equal lengths according to the measurements you've determined. If you want the four ends of the vertical supports to serve as the top of your shelving unit and you'll be making more than one cut, mark the ladder carefully before you saw. Double-check that the rungs on the two pieces line up. The rungs support the shelves, so the shelves will be uneven if the rang on one ladder piece is higher or lower than the corresponding rang on the other ladder piece. Make the cut as even as possible, but keep in mind you'll be attaching the bookshelf supports to the wall when the unit is complete, so wobbling won't be an issue.
Determine the number of shelves you'll need and their dimensions. Figure out how close you want the shelves to be. Plan on one shelf each for the top and bottom rungs, then work toward the centre to determine your spacing, skipping rungs for more space between shelves if needed. The length of the wood depends on how long you want your shelves. However, to prevent the shelves from bowing under the weight of books or other heavy materials, stay within a three-foot to four-foot range. The width of the shelves depends on the width of the rungs between the ladder's vertical supports. The shelves will slip over the rungs, so measure carefully to make sure you don't choose wood that's too wide to fit or so narrow you can't screw the shelves to the supports.
Purchase or reuse wood for your shelves. Options include plain wood planks, melamine board shelves (such as those used with wall brackets), unpainted wood shelves from the craft store, shelves recycled from a dismantled bookcase, leftover wood from other do-it-yourself projects and recycled barn wood. Consider the design style of the room where you'll be using the bookcase---for instance, rustic, shabby chic, funky, utilitarian or contemporary---when selecting wood for the shelves. With some styles, mismatched shelving would look great. With others, clean lines and uniformity of colour and shape would be important.
Prepare the ladder pieces and shelves. Wash with citrus-based wood soap and water to clean. Scrape off any loose paint. If the ladders or shelves are rough in places, smooth them with a sandpaper labelled "for general sanding." Further preparation depends on the condition you want for your shelving unit. The more rustic the appearance, the less preparation the elements will need. On the other hand, if you plan to paint the unit, take more care in sanding the ladder and shelves. Wipe everything with a tack cloth or rag to remove dust and debris.
Fasten the shelves to the ladders. Start by propping one ladder length upright. Slip the first shelf into position over the bottom rang. Mark where to drill pilot holes in the sides of the shelf and the two vertical portions of the ladder. Remove the shelf and drill the holes. Slip the shelf back into place, lining up the pilot holes, and secure the shelf to the supports with wood screws that are long enough to go through the ladder and into the shelf. If the ladder piece is too unsteady to work upright, lay the ladder on its side on the floor and put something under the other end of the shelf to make it level while you mark, drill and secure the shelf.
Position the second ladder so you can slide its bottom rang under the free end of the shelf. If you prefer to work on the floor, lay both ladders on their sides parallel to each other, then scoot the second ladder's bottom rang under the free end of the shelf. Mark corresponding pilot holes on the sides of the free end of the shelf and on the second ladder. Drill the four pilot holes, slip the shelf back into place with pilot holes aligned and screw the shelf into the second ladder piece.
Repeat with the top rungs of the ladders: Position the shelf, mark and drill pilot holes, and secure the shelf to both ladders. Continue the same procedure with each of the remaining shelves, simply slipping each shelf into place through the space above the rungs.
Leave the surface of the assembled bookshelf as is if you want a shabby or rustic effect. Otherwise, stain or paint the unit as desired. Since old wood can be porous, consider sealing any unfinished wood before painting. Apply at least two coats of paint for durability. If staining, use a combined sealer/stain product to save time and expense.
Decide exactly where you want the bookshelf to stand against the wall. Mark the back vertical supports of both ladders for pilot holes; position these holes about one foot from the bottom and one foot from the top of the back supports on each ladder. Drill the holes using a bit that corresponds to the size of the screw you'll be using with the wall anchors. These screws must be long enough to go through the ladder support and into the wall anchor for a secure hold. Mark the wall with corresponding pilot holes; this time use a drill bit slightly larger than the wall anchors you'll be inserting.
Install the anchors in the wall pilot holes by tapping or screwing, depending on the type of anchors you're using. Align the ladder pilot holes with the anchor holes. Screw through each ladder pilot hole into the corresponding wall anchor, securing the shelving unit to the wall.
If you'd rather not drill through the ladder supports to attach the shelf unit to the wall, use shelf brackets, also known as L brackets, instead. Choose brackets that are an appropriate size for the weight of the ladder and shelves in your unit. Attach two brackets, evenly spaced, to the bottoms of the top two or three shelves so the short part of the L extends down. Scoot the unit against the wall, then screw the brackets to the wall. Use wall anchors for added security. If you're unsure what size or type wall anchors and screws you need for your particular shelf unit, consult the sales staff at your local hardware or home improvement store for assistance.