Post by ogeezer on May 2, 2007 12:39:30 GMT -6
The framing square is one of the most used building tools of a journeyman carpenter but unfortunately today with so few really profficient craftsmen around, being replaced by undertrained construction assembly workers and technicians with electronic builder calculators, this tool is slowing slipping into disuse, mainly because nobody knows the myriad uses that can be solved with this simple construction device.
The framing square consists of a wide, long side, called the Blade and a narrow, shorter side called the Tongue. the blade and tongue form a right angle. The face of the square is the side one sees when the square is held with the blade in the left hand, the tongue in the right hand, and the heel poited araw from the body. The blade is 24" long and 2" wide. The tongue is 1 1/2 inches wide and typically is 16" long.
The outer and inner edges of the tongue and blade, on both face and back, are graduated in inches. On the back of the square, the outer edge of the blade and tongue is graduated in inches and twelfths of inches. The inner edge of the tongue is graduated in inches and tenths of inches. The inner edge of the blade is graduated in inches and thirty-seconds of inches on most squares.
Generally the twelfths scale provides various shortcuts in problem solving of dimensions in feet and inches to be reduced to 1/12th by simply allow each each graduation on the 12th scale to represent 1 inch. Conversely the tenths scale provides a means to solving problems dealing with surveyor measures rooted in whole numbers and tenths. For most woodworking and framing tasks the 16th scales are utilized.
In addition to the unit of measure scales, a good framing square will have a hundreths scale, located on the back of the tongue, in the apex (corner) of the square with incorporates a sixteenths conversion scale. This assists in determining rafter lengths when a decimal factor is given.
An octagon scale (aka eight-square scale) is located in the middle of the facr of the tongue. It is used to layout an octagon (8-sided figure) in a square of given even-inch dimensions. Using a set of dividers, it is easy to determine the width in inches between each of the eight sides of the octagon.
There are three tables on the framing square: the rafter table located on the face of the blade; the brace table, located on the back of the tongue; and the Essex table, located on the back of the blade.
The brace table sets forth a series of equal runs and rises for every 3-unit intermal from 24/24 to 60/60, defining the length of the hypotenuse, for each give run and rise. The hypotenuse the length of measure of a brace member, from long point to long point (tip to tip), measured in inches and decimal place. In addition, a good framing square will have a run and rise unit that are not equal, namely 18/24, which has a 30 inches hypotenuse. Through the use of extrapulation by algebraic expression one can easily determine brace lengths for runs and rise not provided on the table.
The Essex table is used to determine board footage in lumber of known dimensions, typically 1x4s, 1x6s, 1x8s, 1x10s, 2x2s, 2x4s, and 2x6s. This table is particularly helpful when order lumber in bulk, instead of purchasing it from do-it-yourself suppliers per the stick.
Having discovered the components of a framing square, a person can accomplish any number of tasks, including:
* squaring a board
* laying out the location of wall studs, ceiling joists, rafters, ridge boards
* stepping off the actual lengths of common, hip, valley, and jack rafters spaced at different centerline positions, including the bird's mouth cut, ridge plumb cut, fascia plumb cut, and length differences of jack rafters at set intervals
* layout octagons, including octagonal inversions
* laying out staircases, steps and stoops
* layout of bracing, purlins, collars, and antirafters
* calculating the length of boards needed for each type of rafter
* calculating the amount of lumber needed for each dimension type
* layout of soffit bands, soffit and gable lookouts, fascia and trim components
* layout of roofs with equal and unequal spans
* layout of splayed, vaulted, cathedral ceilings
* layout of dormers and chimney frameworks
* framing of gable, hip, mansard, gambrel, and shed roofs
* truss construction
* layout of floor bridgeworks, fireblocks, trimmers, king studs, headers, frame corners, frame tees, lathing,
* Calcualte proportions, enlargements, and calculate wages
* Calculate the carrying capacity of pipes and even figure out what size pipe that would be needed to carry the capacity of two different sized pipes
* Find the center of any circle or disk,
* Use framing square to draw a circle or ellipse
plus a host of other uses specialty uses.
The following link, tho not as absolute source of every bit of information for use of a framing sqare does make for a excellent definitive start for using this building tool for more than a square or a woodbutcher's boomerang:
www.tpub.com/content/construction/14044/css/14044_53.htm