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You can count on a good plan
A successful building or remodeling job requires not only a plan, but also the skill to interpret it and an understanding of the mathematics behind it. Whether you are a builder by trade or a do-it-yourself carpenter by choice, turn to this newly updated guide for easy explanations of the math involved and clear instructions on developing and using the necessary plans and ...
You can count on a good plan
A successful building or remodeling job requires not only a plan, but also the skill to interpret it and an understanding of the mathematics behind it. Whether you are a builder by trade or a do-it-yourself carpenter by choice, turn to this newly updated guide for easy explanations of the math involved and clear instructions on developing and using the necessary plans and specifications.
* Explore the different types of wood products and learn what is best for your purpose
* Choose appropriate building materials for weather and other natural factors
* Refresh your knowledge of fractions, ratios, geometry, and measurement
* Understand how to use basic surveying tools
* Become familiar with the design process and recognize various styles of architecture
* Learn to read architectural drawings and work with computer design
The strength and stability of any structure depend heavily on the fastenings that hold its parts together. One prime advantage of wood as a structural material is the ease with which wood structural parts can be joined together with a wide variety of fastenings-nails, spikes, screws, bolts, lag screws, drift pins, staples, and metal connectors of various types. For utmost rigidity, strength, and service, each type of fastening requires joint designs adapted to the strength properties of wood along and across the grain and to dimensional changes that may occur with changes in moisture content.
Nails are the most common fasteners used in construction.
Up to the end of the Colonial period, all nails used in the United States were handmade. They were forged on an anvil from nail rods, which were sold in bundles. These nail rods were prepared either by rolling iron into small bars of the required thickness or by the much more common practice of cutting plate iron into strips by means of rolling shears.
Just before the Revolutionary War, the making of nails from these rods was a household industry among New England farmers. The struggle of the Colonies for independence intensified an inventive search for shortcuts to mass production of material entering directly orindirectly into the prosecution of the war. Thus came about the innovation of cut nails made by machinery. With its coming, the household industry of nail making rapidly declined. At the close of the eighteenth century, 23 patents for nailmaking machines had been granted in the United States, and their use had been generally introduced into England, where they were received with enthusiasm.
In France, lightweight nails for carpenter's use were made of wire as early as the days of Napoleon I, but these nails were made by hand with a hammer. The handmade nail was pinched in a vise with a portion projecting. A few blows of a hammer flattened one end into a head. The head was beaten into a countersunk depression in the vise, thus regulating its size and shape. In the United States, wire nails were first made in 1851 or 1852 by William Hersel of New York.
In 1875, Father Goebel, a Catholic priest, arrived from Germany and settled in Covington, Kentucky. There he began the manufacture of wire nails that he had learned in his native land. In 1876, the American Wire and Screw Nail Company was formed under Father Goebel's leadership. As the production and consumption of wire nails increased, the vogue of cut nails, which dominated the market until 1886, declined. The approved process in the earlier days of the cut-nail industry was as follows. Iron bars, rolled from hematite or magnetic pig, were fagotted, reheated to a white heat, drawn, rolled into sheets of the required width and thickness, and then allowed to cool. The sheet was then cut across its length (its width being usually about a foot) into strips a little wider than the length of the required nail. These plates (heated by being set on their edge on hot coals) were seized in a clamp and fed to the machine, end first. The cutout pieces, slightly tapering, were squeezed and headed up by the machine before going to the trough.
The manufacture of tacks, frequently combined with that of nails, is a distinct branch of the nail industry, affording much room for specialties. Originally it was also a household industry, and was carried on in New England well into the eighteenth century. The wire, pointed on a small anvil, was placed in a pedal-operated vise, which clutched it between jaws furnished with a gauge to regulate the length. A certain portion was left projecting. This portion was beaten with a hammer into a flat head.
Antique pieces of furniture are frequently held together with iron nails that are driven in and countersunk, thus holding quite firmly. These old-time nails were made of foursquare wrought iron and tapered somewhat like a brad but with a head that, when driven in, held with great firmness.
The raw material of the modern wire nail factory is drawn wire, just as it comes from the wire drawing block. The stock is lowcarbon Bessemer or basic open-hearth steel. The wire, feeding from a loose reel, passes between straightening rolls into the gripping dies, where it is gripped a short distance from its end, and the nailhead is formed by an upsetting blow from a heading tool. As the header withdraws, the gripping dies loosen, and the straightener carriage pushes the wire forward by an amount equal to the length of the nail. The cutting dies advance from the sides of the frame and clip off the nail, at the same time forming its characteristic chisel point. The gripping dies have already seized the wire again, and an ejector flips the nail out of the way just as the header comes forward and heads the next nail. All these motions are induced by cams and eccentrics on the main shaft of the machine, and the speed of production is at a rate of 150 to 500 complete cycles per minute. At this stage, the nails are covered with a film of drawing lubricant and oil from the nail machine, and their points are frequently adorned with whiskers-a name applied to the small diamond-shaped pieces stamped out when the point is formed and which are occasionally found on the finished nail by the customer.
These oily nails (in lots of 500 to 5000 pounds) are shaken with sawdust in tumbling barrels from which they emerge bright, clean, and free of their whiskers, ready for weighing, packing, and shipping.
The Penny System
This method of designating nails originated in England. Two explanations are offered as to how this interesting designation came about. One is that the six penny, four penny, ten penny, and so on, nails derived their names from the fact that 100 nails cost six pence, four pence, and so on. The other explanation, which is the more probable of the two, is that 1000 ten-penny nails, for instance, weighed ten pounds. The ancient, as well as the modern, abbreviation for penny is d, being the first letter of the Roman coin denarius. The same abbreviation in early history was used for the English pound in weight. The word penny has persisted as a term in the nail industry.
Nails are the carpenter's most useful fastener, and a great variety of types and sizes are available to meet the demands of the industry. One manufacturer claims to produce more than 10,000 types and sizes. Figure 1-1 shows some common types.
Nails also have a variety of characteristics, including different points, shanks, finishes, and material (see Figure 1-2). The following shapes of points are available:
Common blunt pyramidal Long sharp
Blunt or shooker
Duckbill or clincher
The heads may be
Oval or oval countersunk
Each of the features or characteristics makes the nail better suited for the job at hand. For example, galvanized nails are weatherresistant, double-headed nails are good for framing where they can be installed temporarily with the second head exposed for easy pulling, and barbed nails are good when extra holding power is required.
Tacks are small, sharp-pointed nails that usually have tapering sides and a thin, flat head. The regular lengths of tacks range from 1/8 to 1 1/8 inches. The regular sizes are designated in ounces, according to Table 1-1. Tacks are usually used to secure carpet or fabric.
Brads are small slender nails with small deep heads (see Figure 1-3). Sometimes, instead of having a head, they have a projection on one side. There are several varieties adapted to many different requirements. Brad sizes start at about ½ inch and end at 1 ½ inches. Beyond this size they are called finishing nails.
The term nails is popularly applied to all kinds of nails except extreme sizes (such as tacks, brads, and spikes). Broadly speaking, however, it includes all of these. The most generally used are called common nails, and are regularly made in sizes from 1 inch (2d) to 6 inch (60d), as shown in Table 1-2 (see Figures 1-4 through 1-8).
You can think of a spike as an extra large nail, sometimes quite a bit larger. Generally, spikes range from 3 to 12 inches long and are thicker than common nails. Point style varies, but a spike is normally straight for ordinary uses (such as securing a gutter). However, a spike can also be curved or serrated, or cleft to make extracting or drawing it out very difficult. Spikes in larger sizes are used to secure rails to ties, in the building of docks, and for other largescale projects.
If you have a very large job to do, it is well to know the holding power of nails (see Table 1-3). In most instances, this information will not be required, but in more than a few cases, it is.
Tests for the holding power of nails (and spikes) ranging in size from 6d to 60d are shown in Table 1-4. It is interesting to note, in view of the relatively small force required to withdraw nails, that spikes take tremendous pulling power. In one test it was found that a spike 3/8 inch in diameter driven 3 ½ inches into seasoned yellow pine required 2000 pounds of force for extraction. And the denser the material, the more difficult the extraction is. The same spike required 4000 pounds of force to be withdrawn from oak and 6000 pounds from well-seasoned locust.
The roofing nail has a barbed shank and a large head, which makes it good for holding down shingles and roofing paper felt without damage (the material couldn't pull readily through the head).
Such nails come in a variety of sizes but usually 3/8 inch to 1 ¼ inch long with the nail sized to the material thickness (see Figure 1-9).
As the name implies, these are for fastening drywall (Sheetrock). The shank of the nail is partially barbed and the head countersunk so that if the nail bites into the stud, it takes a good bite. Drywall nails come in a variety of lengths for use with different thicknesses of Sheetrock (see Figure 1-10).
Masonry nails are cut (that is, stamped) out of a sheet of metal rather than drawn and cut the way wire nails are (see Figure 1-10). A masonry nail is made of very hard steel and is case hardened. It has a variety of uses but the most common is probably for securing studs or furring to block walls. Safety is important when doing any kind of nailing, but, when using masonry nails, it is particularly important to wear protective goggles to guard the eyes against flying chips.
The most tenacious of all nails in terms of holding power is the spiral nail (also known as the drive screw). Its shank is spiral so that as the nail is driven, it turns and grips the wood. Its main use is to secure flooring, but it is also useful on rough carpentry.
This fastener is a small section of corrugated metal with one sharpened and one flat edge. Corrugated fasteners are often used for making boxes or joining wood sections edge to edge (see Figure 1-11). They come in a variety of sizes.
Many varieties of staples are available, from ones used to secure cable and fencing to posts (such staples are always galvanized) to ones used in the various staple guns. Fence staples range in size from 7/8 inch to 1 ¼ inches, and some are designed (the so-called slash point) so that the legs spread when the staple is driven in place. This makes it grip better.
Selecting Nail Size
In selecting nails for jobs, size is crucial. The first consideration is the diameter. Short, thick nails work loose quickly. Long, thin nails are apt to break at the joints of the lumber. The simple rule to follow is to use as long and as thin a nail as will drive easily.
Excerpted from Audel Carpenter's and Builder's Math, Plans, and Specifications by Mark Richard Miller Excerpted by permission.
All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.
Excerpts are provided by Dial-A-Book Inc. solely for the personal use of visitors to this web site.
|About the Authors||xv|
|Chapter 1||Nails, Screws, Bolts, and Other Fasteners||1|
|The Penny System||3|
|Selecting Nail Size||12|
|Dimensions of Screws||18|
|Shape of the Head||18|
|How to Drive a Wood Screw||18|
|Strength of Wood Screws||21|
|Manufacture of Bolts||23|
|Kinds of Bolts||27|
|Proportions and Strength of Bolts||27|
|Fasteners for Plaster or Drywall||33|
|Hollow Wall Screw Anchors||34|
|Hanger Bolts, Dowel Screws, and Toggle Studs||37|
|Chapter 2||Wood as a Building Material||41|
|Growth and Structure of Wood||41|
|Softwoods and Hardwoods||41|
|Seasoning of Wood||44|
|Virgin and Second Growth||54|
|Time of Cutting Timber||54|
|Air-Dried and Kiln-Dried Wood||54|
|Sapwood Versus Heartwood||55|
|Defects and Deterioration||55|
|Decay of Wood||57|
|Chapter 3||Lumber, Plywood, and Other Wood Products||67|
|Standard Sizes of Lumber||67|
|Softwood Lumber Grades for Construction||68|
|Types of Plywood||79|
|Grades of Plywood||79|
|Retail Yard Inventory||82|
|Important Purchase Considerations||86|
|Chapter 4||Strength of Timbers||89|
|Working Stresses for Columns||91|
|Transverse or Bending Stress||96|
|Modulus of Elasticity||100|
|Allowable Loads on Wood Beams||100|
|Breaking Loads on Wood Beams||102|
|Wind Loads on Roofs||104|
|Chapter 5||Mathematics for Carpenters and Builders||111|
|Notation and Numeration||111|
|Signs of Operation||115|
|Use of the Signs of Operation||116|
|Rule of Three||128|
|Powers of Numbers (Involution)||129|
|Roots of Numbers (Evolution)||129|
|Board or Lumber Measure||136|
|Measures of Weight||137|
|The Metric System||140|
|Functions of Numbers||197|
|Construction of the Wye Level||199|
|Lines of the Level||201|
|Adjustments of the Wye Level||202|
|Methods of Leveling||206|
|Directions for Using Level||209|
|Construction of the Transit||212|
|Lines of a Transit||218|
|Adjustments of the Transit||219|
|Adjustments of the Compass||221|
|Instructions for Using the Transit||222|
|Care of Instruments||224|
|Chapter 7||The Design Process||233|
|An Example of Design||236|
|Conference with Builder||236|
|Changes Agreed On||238|
|Chapter 8||Building Specifications||243|
|Example of Specifications||243|
|Height of Ceilings||243|
|Interpretation of Drawings||244|
|Spacing and Bridging||247|
|Sheathing and Sheathing Paper||247|
|Condition of Bids||252|
|Chapter 9||Architectural Drawings||255|
|Use of Drawings||255|
|Top View or Plan||256|
|Right-End View (Elevation)||256|
|Left-End View (Elevation)||258|
|Directions of View for Sectional Views||259|
|Chapter 10||Building Styles Explored||281|
|The Two-Story New England Colonial House||281|
|A House of Modern Architecture||284|
|The Contemporary House||285|
|Utility Pole-Type Building||287|