Nails, when they became cheap, replaced dowels, doveta Is, and mortise-and-tenon joints. Most nailing is called surface nailing: driving a nail straight through one board in order to fasten it to another. This is the way roofing planks and plywood are installed, as well as wooden siding.
But one of the most valuable skills in timber framing for the rest of us is to learn how to toenail properly. A toenail (in carpentry) is a nail driven at an angle that allows us to join one timber to another where they meet at right angles. It is a fairly strong method of nailing, because toenails are always installed opposite each other, as in Fig. 4.21. Some of the nails will always provide shear strength, no matter which way a timber is forced. Toenails don’t pull out easily, as you will discover when you make a mistake, and have to take your own work apart.
Toenails should be installed at about a 60-degree angle, as shown in the illustration. With two-by framing, an 8-penny (2.5-inch) toenail is started about three — quarters-inch (1.9 centimeters) up the upright. But with heavy timbers, I tend to use a larger nail, such as a 16- penny (3.5-inch) nail, and start it an inch or even 1.25- inch (3.2 centimeters) up the side of the post. With the 60-degree angle, you will still get plenty of purchase into the wood below.
The "law of the toenail" says that you will move the base of the post or beam in the direction in which you are striking. You can avoid this by marking the post in its correct position with a pencil and then starting one of the toenails until it grabs the substrate. You can drive it until the post begins to move, then stop. Install the opposite toenail as a reactionary thrust. It will move the post back into the correct position. By working on one toenail, then its opposite, you can set the post firmly, right where it belongs.
You can lessen the chance of splitting wood while toe-nailing if, first, you hit the pointy end of a nail quite stiffly with a hammer while its head bears against something hard, such as concrete. This will dull the point. A pointed nail tends to spread the fibers and split the wood, but a blunt nail will simply puncture the wood grain as it penetrates: no split. With large nails, pre-drilling the angle will also reduce the chance of splitting wood and make the nail easier to install.
As the years go by, I use nails less and screws more. Screws have the advantage of being removable. Toescrewing is my term for using a screw instead of a nail in a toe-nailing situation. With large (3.5- to 4-inch or 10.1 centimeter) deck screws, drill a small pilot hole first to lessen the chance of splitting. Use an electric drill to install these screws, not a screwdriver. Robertson screws — the ones with the little indented squares in the head — drive more positively than Phillips or slotted screws and the heads are less likely to get mangled by the driving bit.
For the remainder of this book, the terms "toenail" or "toenailing" also implies the optional use of screws.
Toenailing can also be used to fasten any beam over a post. The toenails (or screws) are driven upward through the post into the beam. See the sidebar on the facing page. The “law of the toenail” is particularly strong In this situation, and screws give a little more control than nails.
Another way to hold the beam fast over a post as by the use of truss plates, as shown in Fig. 4.22a, and you really need to place one each side of the wall to get the proper strength. The downside of this method is that the truss plates will often be in view in this application, and they are not particularly nice looking. You can beat this by making your own heavy (one-eighth-inch or 3.2 millimeter) pieces, drilling holes in them, and installing them as in Fig. 4.22b, with, say, two one-quarter-inch by 3- inch (0.6- by 7.6-centimeter) lag screws into each member (four per plate, each side of the joint.) Paint them whatever color tickles you. But black is nice.
Yet another post-to-beam fastening method is shown in Fig. 4.22c, in which the metal can be hidden inside of an infilled wall. Here, right-angle fasteners, commonly available at any hardware store, are used instead of toenails. These are like ordinary truss plates, but bent in the middle to form a right-angle. In a pinch, I have bent truss plates into right angles for the purpose, as in Fig. 4.35. Use four — penny (4d) nails, which are one-and-a-half inches long. You don’t have to put a nail in every hole provided. I generally use about half the holes, as long as this is at least five in number, more with larger plates or right-angle fasteners.
