Like a lot of craftsmen, I became a carpenter and cabinetmaker by accident. After graduating from college with a degree in Comparative Literature, I hired on with a small Brooklyn contractor. John and his crew of four or five guys did concrete work, kitchen remodeling, brownstone renovations, loft conversions, decks, built-ins, office renovations—you name it. Working with John turned out to be the equivalent of another college education.
For the first few weeks, he kept me in the shop as another pair of hands, mainly to clean up and pack the laminate- and hardwood-veneer cabinets that he built for installation on his jobsites. Before long, he gave me a lesson in how to operate the shop tools, then started to teach me cabinetmaking.
For my first job, John sent me to measure a wall in an apartment where we were to install a wall-to-wall, floor-to-ceiling built-in with shelves and doors. Then he left me alone to work out the number and sizes of the cabinet modules I'd need to build to cover that wall.
As I recall, I divided the length of the wall into six equal parts so that each component would be no wider than 24 inches; convenient enough to fit through the doors, up the stairs, and through the hallways we'd have to negotiate to get the components into the apartment for installation. We would screw the boxes together side to side on site, lag them to the wall, and finish the raw plywood edges with oak veneer tape.
I built the cabinets and cut the shelves in the shop, and John and I trucked them into the city. When we assembled the modules, however, we found the unit to be about 1/2-inch too wide to fit between the walls at either end.
As we drove back to the shop to alter one cabinet module, John explained the principle of accumulated error and how it applied in this case. First, he pointed out that despite careful measuring, I was likely to be off by a little as the thickness of a pencil line on a high percentage of them. And he noted that I had measured the length of the wall along the floor only and had no clue that the walls were out of plumb (the measurement along the top of the wall was shorter than at the bottom). With six shelf widths and 12 cabinet sides joined to make up the units' full width, plus whatever error I might have made when originally measuring the wall, it wasn't surprising that the accumulated errors added up to make the assembled unit too big to fit.
The first inference, of course, is to never plan to make the major components of a built-in fit exactly. Design it with reveals or filler panels that can be scribed to disguise or cover up gaps, and aim to make the assembly a little smaller than the space into which it will be installed.
I also decided to spent time learning to measure and cut more accurately. I quickly figured out how to position one eyeball directly in front of the mark on the ruler before transferring it to the work piece to avoid parallax distortions. And I learned to make marks only with a sharp pencil or a thin knife blade to avoid ambiguity that comes with drawing cut lines that are too thick.
Marking in Place
In the course of things, I also figured out that it is actually faster and more accurate to rely on a tape measure or folding rule as little as possible. When installing crown molding, for example, work around the room in one direction, and start on a long wall. For straight lengths, plan coped and butts for the same end (when working left-to-right, copes on the left and butts on the right works best). Leave out the fasteners at the starting corner to make it easier to snap the last piece into place.
When you need to cut a number of pieces that must match in width or length or both, it is better to measure once and set up a guide or jig that enables you to make repetitive cuts without measuring for each one. To cut shelves for a bookcase, for example, set the fence on a table saw or the rip guide on your portable circular saw, and rip as much stock to width as you'll need. Then set a stop on your miter saw table and cut uniform lengths.
Spacing and Aligning Shelves with Minimal Measuring
You don't need to make a whole lot of finicky measurements to get shelves evenly spaced and perfectly aligned in a bookcase. To fasten fixed shelves with consistent spacing one above another, cut two identical panels equal in height to the desired space between the shelves. Clamp the spacer panels against the sides of the cabinet carcass, set a shelf on the spacers and fasten it to the cabinet. Remove the spacers and repeat as needed.
To bore consistently spaced holes for adjustable-shelf rests, cut a panel from thin plywood or hardboard equal in width and length to the inside dimensions of the cabinet sides. Lay out the centers of the holes you need for the shelf rests, then bore holes where marked with a bit equal in diameter to the shelf rest pin. Use this template to bore holes in the cabinet sides making sure to set it against the cabinet wall with the same end down and the same face out for each set of holes.
Guides for Edge Cuts
For decking that cantilevers over an end joist, don't try to cut each board to a certain length and line up the ends as you fasten. Instead, fasten all of the decking in place using boards approximately the correct length, letting the ends fall where they may. Then set up a straightedge guide that enables you to cut the ends off in a straight line all in one pass. The only critical measurement here is the distance between the edge of the shoe and the blade of your circular saw. If the edge of the decking is to be curved, cut an arc-shaped guide from a sheet of plywood and clamp or screw it to the deck surface to guide a jigsaw or reciprocating saw for a smooth, graceful curve.
Layouts with Story Poles
Story poles come in handy for layouts and installations in which you have to maintain consistency in a repeated pattern or visual alignment of a number of components. A story pole that is carefully prepared is virtually foolproof because it enables consistent transfer of a single set of marks rather than repeated measurements. Story poles are widely used in masonry work and exterior siding applications, as well as interior trim work and cabinet installation.