A Treatise On Architecture And Building Construction Vol3: Stair Building, Ornamental Ironwork, Roofing, Sheet-Metal Work, Electric-Light Wiring And Bellwork
Stair building grew out of the necessity of securing an easy and safe passage from one level, or floor, to another. Such a passage might therefore be regarded in its inception as an inclined plane which connects two horizontal planes and provided with a series of equal risers, or steps, formed for the purpose of giving a sufficient footing to facilitate travel.
Title | A Treatise On Architecture And Building Construction Vol3: Stair Building, Ornamental Ironwork, Roofing, Sheet-Metal Work, Electric-Light Wiring And Bellwork |
Author | The Colliery Engineer Co. |
Publisher | The Colliery Engineer Co. |
Year | 1899 |
Copyright | 1899, The Colliery Engineer Co. |
Amazon | A Treatise On Architecture And Building Construction |
Prepared for Students of The International Correspondence Schools Scranton, Pa
Volume III
Stair Building, Ornamental Ironwork, Roofing, Sheet-Metal Work, Electric-Light Wiring And Bellwork
With Practical Questions And Examples
Stair Building. Introduction- 1. Stair building grew out of the necessity of securing an easy and safe passage from one level, or floor, to another. Such a passage might therefore be regarded in its inception as an inclined plane ...
Stairway Construction. Materials Used- 2, The materials most commonly used in the construction of stairways are stone, iron, and wood; the selection of material should be based on the location and the use to be made of the stairway. If pla...
Terms Used In Stair Building- 3. In stair building, a riser and tread together are termed a step, the riser being the upright portion which supports the tread, or horizontal part, upon which the foot is placed. The nosing is the p...
Details Of Construction. Risers And Treads. 6. Height Of Risers- In setting out a stairway, the first consideration should be to ascertain the exact height between the floors, the height to be measured from the top of the floor below to the top of the floor above. ...
7. Proportioning Treads And Risers- The next step is to ascertain the width of the treads, not forgetting the rules of proportion between treads and risers, and always remembering that the number of treads in each flight is one less tha...
Headroom- 8. In trimming joists of staircases, the two cross trimmers which are called headers should be so placed as to allow sufficient headroom to meet all probable requirements of a stairway. The header (wh...
Stringers. 9. Laying Out- A straight stringer is laid out by means of a pitch board, shown at (a) in Fig. 4. This board should be made of thin wood, with the grain parallel to the hypotenuse, so that the effects of shrinkage w...
10. Scribing Wall Stringers- When the treads and risers are supported by rough cut carriages, it becomes necessary to cut a wall stringer that will fit around the steps and make a finish with the wall. In Fig. 8 is shown a method...
Construction Of Steps- 11. A portion of the upper edge of the riser may be tongued into a groove in the under side of the tread, as shown at a in (a), Fig. it, instead of letting the whole thickness of the riser into the tr...
12. Bull-Nose. Steps- A form of step much used is represented in Fig. 10. The solid block is sawed into shape, and the riser is sawed out as shown, leaving a veneer for the face of the riser. The end b is firmly fastened t...
13. Curved Risers- Where risers are curved, they should be made of solid wood, or of curved strips of seasoned wood glued solidly together. It is often difficult to get seasoned wood in pieces large enough to make a sol...
14. Patforms- Where the stairways of a building are of considerable length, and are straight in plan, it is best to break the flight by a platform. Such a platform may be projected from the side wall, as shown in F...
Cylinders- 15. In geometrical stairways, the hand rail travels, unobstructed by newels, from the first step to the last, sometimes over six or more flights; it then becomes necessary to wreath the stringer and r...
Miscellaneous Details. 16. Moldings- All base and stringer moldings should be worked out of solid wood. Work that is to be bent is generally stronger when laminated, as shown in Fig. 16; but for moldings this method cannot always be used...
17. Erection- If the stairway is put up against the brown-mortared wall, the finished parts must be well covered with building paper, and rough boards placed over the paper on the treads, to remain until the interi...
Balustrades- 18. Newel posts, or newels, are used to support the hand rail, and are either made of solid materials and turned, or built up, box-like, in which case they are called boxed novels. They vary in design...
20. Hand Rails- The making of hand rails is a part of stair building which involves complex geometrical problems that belong properly to the stair builder. The architect, however, should see that the rail - except wh...
21. Ramps And Easements- In an open-newel stairway the rails usually meet the newels one above the other. To bring them to the same level, the rail must be ramped, and sometimes they are ramped and kneed - the latter being a ...
22. Stiffening Hand Rails- Continued hand rails are sometimes provided with an iron brace extending across the cylinder from the facia to the bottom of the rail. Instead of this brace, an iron baluster is often placed at each e...
Stairway Design And Construction. Ordinary Forms. 23. Step Ladders- One of the simplest forms of stairways in use is a step ladder, fixed or movable, such as is sometimes built from an attic floor to the roof, as is shown in Fig. 18, where (a) is a plan, and (b) an el...
24. Plank Stairway- In (a) and (b), Fig. 19, are shown the plan and elevation of a strong stairway, such as may be required for a shop or factory; a and b are newels, 6 inches square, to which 4 X 1 1/2 hand rails c an...
Geometrical, Stairway. 25. Straight Stairway- In Fig. 20 are shown the plan (a) and elevation (d) of a straight stairway with a 6-inch cylinder. The first requirement in planning this stairway is to fix the number and height of risers. The story ...
26. Platform Stairways- The plan (a) and the elevation (5) of a half-turn platform stairway, with a continued hand rail around a 7-inch cylinder, is shown in Fig. 21. This kind of a stairway is easy of ascent, breaking the f...
27. Winding Treads- In Fig. 22 is shown an enclosed stairway, illustrating the method of laying out the wall stringer, easement curves, etc. The widths of the winding treads at the wall are projected down from the plan b...
28. Easement Curves- At the angles, easement curves are necessary, or, at least, advisable. At h is shown a method of drawing an easement curve. From the vertex h lay off equal distances in both directions, as 1, 2, 3, 4,...
29. Items Of Detail- Both wall and front stringers are to be mortised, or housed; for the steps, the treads and risers are to be glued together, wedged and back nailed, as before explained, in order to secure good, solid ...
30. Double Winders- In Fig. 23 is shown a stairway winding one-quarter turn at the top and bottom, with an 8-inch cylinder, for a continued hand rail. In planning winding stairways, it is important to make the treads as ...
31. Width Of Winders- The winding treads must be made of uniform width around the cylinder, so as to obtain a uniform curve in the rail. It will be observed that there is a 5-inch width introduced between the straight flig...
32. Development Of Stringers- At (c) and (e) in there are 4 winders, differing but little from the plan shown in Fig. 23; while in (b) there are 3 winders with slightly curved ends. The 5 risers so changed in their arrangement in ...
33. Arrangement Of Winders- In Fig. 24 are shown the plans of two different stairways brought together for comparison, each having one-quarter turn with an 8-inch cylinder and a continued hand rail. It will be seen that by the a...
34. Carriage Timbers- In Fig. 25 is shown the plan of the top winders of a stairway similar to that in Fig. 23, a, b, and c being the principal timbers in position. The timber a is set in place after the stringers are put ...
Newel, Stairways- 35. In Fig. 27 is shown a plan of a quarter-platform open-stringer stairway with 4-inch square newels framed in the angles, the handrails making straight connections with the newels, as shown in Fig. ...
36. Open Stringers- In Fig. 29 are shown an elevation and section of an open stringer, where fillets are used. At (a) is a portion of the stringer showing the step trim with fillets a, a; the lower portion of the stringe...
37. Close Stringers- In Fig. 30 are shown a plan (a) and an elevation (b) of a quarter-platform stairway with 4 risers in the flight adjacent to the landing, close paneled and molded stringers, 6-inch square newels, 2 1/2...
38. Half Newels- In neweled stairways, the hand rails should always finish against a half newel at the wall connection, and the ends of the half newels may be shown below the soffit. Where half newels are placed on th...
39. Newel Posts And Rails- The length of newel posts is governed by the depth of the stringer, including the soffit molding. Fixing the height of the easement at G, Fig. 30, and the height of the level hand rail at j, the heigh...
40. Special Arrangement Of Newels- In Figs. 31 and 32 are shown the plan and elevation of a quarter-platform stairway having a quarter-cylinder connection to the landing, thus avoiding the use of a second newel. 41. In Fig. 33 are sho...
42. Swelled Steps And Curved Stringers- It is very desirable to give a stairway a pleasing appearance at its start; with that end in view, the stairway is often widened adjacent to the newel by curving out the front stringer 6 inches or mor...
43. Curtail Step- In Fig. 37 is shown a method of describing the curves of a curtail step. Begin by drawing a circle of a size greater than that required to enclose the required scroll. Let a b c d be such a circle; di...
Special Forms Of Stairways. 44. Quarter Platform- In Fig. 40 is shown a plan of a quarter-platform stairway with a quarter cylinder for a continued hand rail. Any radius of cylinder considered desirable may be used, but if the risers o b and o' b' be...
45. Quarter-Turn Winding- The plan of a quarter-turn winding stairway, with a quarter cylinder for a continued hand rail, and with regular treads above and below, is shown in Fig. 41. It will be noticed that the treads adjoini...
46. Platform and Curved Risers- In Fig. 42 is shown a plan of a stairway which includes two platforms with a step and two curved risers in the 10-inch cylinder between the platforms, making a half turn. The wreathed rail over this p...
47. Newel Between Quarter Cylinders- Fig. 43 is a plan of a stairway with a newel post set between quarter cylinders on the landing of a flight; the hand rail in this case would be bolted to the newel. Fig. 43. ...
48. Half-Turn Platform- In Fig. 44 is shown a half-turn platform stairway. The face of the top riser of the lower flight and the bottom riser of the upper flight have a slight curve adjacent to the cylinder. By this method t...
49. Winding Stairway- Fig. 45 is a plan of a winding stairway with 17 risers, and 10-inch cylinders for a continued hand rail. This arrangement is suitable where space is limited and where the entrance to the staircase is ...
50. Arrangement For Intermediate Floor- Fig. 46 is a plan for the starting and landing of two flights connected by a 12-inch cylinder; such an arrangement is used where the short flight ascends to an intermediate floor on the platform level...
51. Quarter Platform With Tangent Between Quarter Cylinders- Fig. 47 is a plan of a quarter-platform stairway for a continued hand rail. The cylinder opening of 18 inches is formed by two quarter circles, each of 5 inches radius, and an 8-inch piece of straight...
52. Quarter Platform With Semicircular Cylinder- Fig. 48 differs from the preceding plan only in the form of its cylinder, which is semicircular in plan, and, while requiring a little more run, furnishes a more pleasing rail and cylinder. Fig. 4...
53. Double Platforms- Fig. 49 is a plan of a platform stairway making a half turn, one riser at the center of the cylinder dividing the space into two platforms. Where the run will permit, it is always advisable to dispens...
54. Quarter Platform With Step- Fig. 50 is a plan of a quarter-platform stairway with a 15-inch cylinder having a regular step at its center. Fig. 50. ...
55. Three-Quarter Turn- Fig. 51 is a plan of a winding stairway making a three-quarter turn, the entrance being at one end of the staircase. Fig. 51. ...
56. Starting Or Landing Winders- Fig. 52 is a plan of a stairway which has winders either at the starting or at the landing. The curving of the risers is resorted to for the purpose of making them occupy less room from l to m. Curvin...
57. Quarter Platform With Newels- Fig. 53 is a plan of a quarter-platform stairway with small newels framed to the stringers in the angles; the hand rail may join the newels either straight, or with easements and with ramp and knee, o...
58. Platform Stairway With Two Return Flights- Fig. 54 is a plan of a platform stairway with two return, or wing, flights, suitable for a public building. The flights and platform may be wainscoted, and, by the introduction of half newels set agai...
59. Circular Stairway- A plan of a circular stairway is shown in Fig. 55; all the risers except the three curved ones at the start radiate from the center b, and are equally spaced at the front and wall stringers. The first...
60. Elliptic Stairway- In Fig. 56 is shown a plan of an elliptic stairway. The usual method of providing a uniform width for the treads along the wall stringer, and also along the front stringer, causes some of the risers t...
Wainscoting- 61. The paneled wall lining for halls and stairways is made of various heights, the arrangement and treatment of the panels being varied to meet the ideas of the designer. In Fig. 57 is shown a portio...
Ornamental Ironwork. Introduction- 1. Iron is used in building construction to serve two purposes, one structural and the other ornamental; but becomes an element of architectural consideration only when both purposes are combined. Unf...
Cast-Iron Work. Method Of Manufacture. Definitions Of Terms- 2. Cast Iron is the term given to that quality of iron which exists when the melted metal is poured into a suitable receptacle, or mold, and allowed to cool and solidify. Cast iron is hard, brittle, a...
Cast-Iron Work. Definitions Of Terms. Method Of Manufacture. Continued- The core is made of sand mixed with oil and flour, or some similar composition, and is molded in a box especially made for it; it is then baked hard in an oven before it is ready for use. The core bei...
Structural Details. 9. Screws And Bolts- In Fig. 7 at (a) is shown what is termed a square-head bolt. These are used for all common connections, such as the joining of two flanges or other surfaces which are not exposed to view. At (b) is sh...
10. Mullions- A window such as shown in Fig. 8 is sometimes so wide that it requires a mullion, and the design of this mullion must be consistent with the rest of the building, no matter what its construction may b...
11. Window Frames- The section of the window soffit shown at Fig. 9 shows a cast-iron frame, the outer edge of which takes the place of the weather stop, and is ornamented with an egg-and-dart molding. The section of th...
Cast-Iron Stairs. Straight-Run Stairs- 14. Stairways in public buildings should be of iron, and by reason of the prominence of their location it is usually necessary that their design should be in accordance with their surroundings. A numb...
Platform Stairs- 18. The stairs shown in Fig. 15 is one of a series of flights that might be used from the basement to the top floor of a building wherein the stairs just described would be suitable in the basement. T...
Semicircular Stairs- 21. In Fig. 19 is shown at (a) the plan of a semicircular stairway; while in Fig. 20 is shown the front elevation at (a), the development of the string at (b), and a detail of the rail on the upper la...
Circular Stairs- 26. A type of circular stairway, similar to that described on drawing plate entitled, Winding Stairs, in the section on Architectural Drawing, is shown in Fig. 22. This stair is suitable in some such ...
Friezes And Balustrades- 27. In Fig. 27 is shown a cast-iron frieze. The ornament is bold, and has considerable relief, but, being entirely on the surface, and not undercut, it does not present any special difficulty in moldi...
Wrought-Iron Work. Methods Of Manufacture. Characteristics- 29. Wrought iron differs from cast iron principally in the characteristics that it is soft, malleable, and fibrous, while the latter is hard, brittle, and crystalline, as explained in Art. 2. This di...
Tools And Implements- 30. In some structural work, cast iron is used extensively on account of its cheapness; but for certain classes of work, cast iron is not suitable, and wrought iron is employed almost exclusively; as,...
34. Grilles- Having described the tools used in working wrought-iron bars into forms from grilles, a few examples of the simpler forms of grilles are shown at Figs. 38 to Fig. 38. Fig. 39. Fig. 40. 41...
Office Grilles- 36. The metal counter rails in banking houses, offices, etc., so far as the grille-work is concerned, are in no way different from the grilles heretofore described; but the arrangement of the supports...
Elevator Enclosures- 37. All the preceding examples of grille-work are suitable for use in elevator enclosures or any similar screen work, and their application to such work will now be considered. In Fig. 50 is shown an ...
Elevator Enclosures. Continued- Fig. 60. 40. The construction of the enclosure, as well as the design shown in Fig. 61, differs considerably from that of the preceding example. With the exception of three details, it is entirely...
Combined Elevator And Stair Shafts- 44. In fireproof buildings it is a common practice to combine the elevators and stairs in one shaft. In such cases the elevator usually occupies the center of the shaft, and the stairway is constructe...
Combined Elevator And Stair Shafts. Part 2- Fig. 71. 47. The risers shown in Fig. 70 (l) are for all starters on each floor, and for all intermediate risers. The facias shown in Fig. 70 (m) are at the start of the upper stories, and form a fin...
Combined Elevator And Stair Shafts. Part 3- Fig. 74. 53. An elevation of the sliding or rolding gate, protecting the entrance to the car, is shown in Fig. 73 (a), while Fig. 73 (e) shows a large scale detail of the bottom of the sliding pos...
Leaves And Foliated Work- 56. All the work considered up to the present time has been purely structural. Such ornament as has been necessary in elevator fronts or office partitions has been of a conventional character, and is ...
Forged Work- 61. In the succeeding pages, descriptions of the illustrations given cannot be more than general, as the chief object is to give examples which are standards of artistic and ornamental design. Instruc...
Gates And Fences- G3. Most of the examples heretofore given have been of light work that could be made without heating the iron, but in Fig. 85 is shown a piece of a more substantial character. The main bars are 1 1/2 ...
Window Guards- 66. A window guard should be primarily a protective device, and secondarily an ornament or decoration. As a rule, especially in private-residence work, the design of these very necessary appendages is...
Lamps And Brackets- 69. For exterior and interior lamp posts and brackets, wrought scroll-and-leaf work lends itself most readily. There is no detail of house furnishings wherein wrought iron can be put to such effective...
Iron Structures- 75. It is sometimes desirable to erect small structures entirely of cast and wrought iron. Of these the most common are the small domes or cupolas crowning the roofs of certain classes of buildings, b...
Roofing. Historical Introduction- 1. The origin of house roofing is to be found in the endeavor and determination of man to provide for his physical wants and comforts. Man, in a primitive and uncultivated state, commenced by rudely i...
2. Tents- The skin tent was much used by the Arabs, and was generally made of goat's skin, dyed black, spread over two or more poles about 8 or 9 feet long. The Australians, the tribes of the Polynesian Archip...
3. Huts- After the tent, came the hut of wood or stone. Fig. 2. The construction of the stone huts, or beehives, so called from their shape (see Fig. 2), was a combination of both house and roof, and may ...
4. Stone And Earth Roofs- The next form of covering was probably that of large stones or monoliths, over which flat stoneswere placed (see Fig. 4). In connection with stone roofs we note also the device of corbeling out each c...
5. Tile Roofs- The history of tiles as a roof covering is too extended to completely review; tiles, however, deserve special mention, because they are the most desirable and the most serviceable materials used for r...
7. Metal Roofs- Metal roofs may rightly be termed modern roofs. Lead was the first of these to be introduced; copper, zinc, and galvanized iron followed. Lead and copper were used in medieval times for covering roofs...
General. Terms And Definitions. Varieties Of Roofs- 9. The names of different roofs are determined: (1) by their style; (2) by their outline; and (3) by their angle of inclination, or pitch. Fig. 10. In Fig. 10, at (a), is shown a pent, shed, or l...
Roofing- 11. The following terms are applied to express the different elements or details which exist in nearly all roofs: Span is the distance between the supports. Rise is the vertical distance between the e...
Design And Construction Of Roofs. General Considerations- 12. In planning a roof, the first thought must be given to the pitch, which depends upon the climate, against which it is to act as a protection; the second consideration is the devices of constructio...
Thatching- 18. Thatching on a house is an admirable covering for securing warmth in winter and coolness in summer, but, being subject to injury from birds and a great risk from fire, is very seldom used. A good ...
Asphalt Roofing- 21. Asphalt, or solid bitumen, is found in several countries. Asphalt, combined with calcareous earth, that is, earth containing lime, forms a compact, semielastic solid, not liable to injury from the...
Asbestos Roofing- 25. Asbestos is a white, gray, or green-gray fibrous variety of amphibole, usually one containing but little aluminum, trenolite, or actinolite; also, improperly, a fibrous serpentine or chrydolite. T...
Shingle Roofing. Wood Shingles- 30. Shingles are made by sawing or splitting chestnut, hemlock, cedar, white pine, or cypress. Chestnut shingles are likely to curl in dry weather, and when damp they swell and bulge; this continued ...
31. Sizes And Terms- The ordinary lengths of shingles are from 16 to 18 inches, or 24 to 27 inches, and the widths, from 3 to 7 or 10 inches. A bundle contains about 250 shingles. Thick shingles measure about 9/16- inch, ...
Laying Shingles- 32. The methods of laying shingles generally in use are: (1), on shingle lath; (2), on boarding without paper or felt; and (3), on matched boarding and lath with felt. The first method is, no doubt, ...
35. Valleys- In finishing against open valleys, care should be taken to cut the shingles parallel to the line of the tilting fillet, or the result will be a wavy line. In constructing close valleys, the shingles ...
35. Valleys. Continued- Table 2 Exposure to the Weather. Inches. Number of Square Feet of Roof Covered by 1,000 Shingles. Number of Shingles Required for 100 Square Feet of Roof. 4 Inches Wide. ...
Tin Roofing. Tin And Tin Plate- 45. Tin, when pure, is a metal of whiteness and brilliancy next to silver. It is highly malleable, but inferior in ductility and tenacity to all metals, except lead. Little affected by the atmosphere,...
48. Manufacturing Terms- The term tin plate has been defined. Terne plate is a plate of sheet iron coated with tin and lead, and is inferior in quality to tin plate. Plates in the market are known as charcoal and coke plates....
Materials Used In Metal Roofing- 49. Solder is an alloy of two or more metals. When melted, it adheres strongly to the clean surfaces of the other metals less fusible. Solders are hard or soft, according to their relative fusibility....
53. Wall Hooks And Roofing Nails- Wall or flashing hooks, as shown at (a), Fig. 41, or b, Fig. 42, hold the flashing in place where it lies against the wall, or they are driven over the apron flashing to prevent it from pulling out; t...
53. Wall Hooks And Roofing Nails. Part 2- Table 5 Size. Inches. Grade. Sheets in Box. Lb. in Box. Gauge. 14x20 IC 112 113 29 14x20 IX 112 143 27 14x...
53. Wall Hooks And Roofing Nails. Part 3- Table 7. Semicircular Eaves Gutters Sheets. Boxes. Girth. Inches. Number of Sheets. Size of Sheets. Inches. Length of Gutter in Feet and Inches. Num...
68. Laying Metal Shingles- Generally these shingles are laid from the eaves up to the ridge. There is, however, a method of laying the shingles from the ridge downwards. In laying shingles of the Gothic pattern (one of which is...
69. Flashings- Hips are finished as shown at a, Fig. 55. The edges of the shingles should be cut to the proper angle and fitted into the groove b of the hip flashing. Fig. 55. Valley flashings, as at a, Fig. 56...
Copper Roofing. Properties Of Copper- 72. Copper is distinguished from all other metals by its peculiar red color. Its resistance to corrosion when exposed to the atmosphere, combined with its lightness, gives it great value as a roof cov...
73. Sheet Copper- Copper is, obtained from its ore by the following process: First, the ore is roasted or calcined; after the roasting, it is melted in a reverberatory furnace, whence it issues in the state called coar...
Laying Copper Roofs- 75. The methods employed in laying copper roofs are usually the same as those required for tin roofing, though the flat roof laid with a lap seam is not to be commended. It is weak, and, being soldere...
Copper Tiles- 80. Copper roofing tiles are made in imitation of most of the different forms of terra-cotta tiles. They are extensively used, principally on account of their cheapness and lightness. Like all other t...
Galvanized Sheet-Iron Roofing- 85. Galvanized iron is iron coated with zinc, the object being to protect its surface from the rapid oxidation taking place when it is exposed to atmospheric influences. The zinc coating is applied to...
Galvanized Sheet-Iron Roofing. Continued- Table 9 Side Lap. Corrugation. Length of End Lap. 1 in. 2 in. 3 in. 4 in. 5 in. 6 in. One Corru-gation Lap. 2 1/2 in. 110 ft. ...
Black Sheet-Iron Roofing- 93. Black sheet iron for roofing is furnished cold rolled and annealed, in gauges ranging from 16 to 26 and in weight from 3/4 pound to 2 1/2 pounds per square foot. Anything lighter than gauge 26 is ...
Sheet-Lead Roofing- 98. Lead, the softest metal in general use, is extremely plastic, very malleable, flexible, and heavy, but lacking in tenacity and elasticity. It is mostly found in combination with other ores, the pr...
Sheet-Lead Roofing. Continued- Table 13 Thickness. Inch. Nearest Simple Fraction. Weight. Pound per Square Foot. .068 l/16 4 .085 5 5 .101 3 6 ...
Sheet-Zinc Roofing- 107. Zinc, one of the useful metals, generally extracted from mountain limestone and magnesium limestone in conjunction with galena, is met with abundantly in the form of a sulphuret. The ore is roast...
Sheet-Zinc Roofing. Continued- Trough And Cap This method is much the same as that used for copper, the difference being that the cap a is slipped over the lock b of the trough, as in Fig. 85, clips not being required to keep it i...
Slate Roofing. Properties Of Slate- 112. Slate used for roofing purposes, commonly known as clay slate, is obtained from an argillaceous or clayey rock, of a compact and fine-grained texture. This rock is formed through the deposition o...
Laying Slate Roofing. 115. Terms Used In Slating- The terms applied to the different parts of roofing slate are: the gauge, or weather, which is that part of the slate which is exposed when laid, as shown at a, Fig. 88; the lap, which is the distance...
116. Nailing- There are two methods of nailing slate: head nailing and shoulder nailing. In head nailing, which is the usual method employed, the nail holes are punched about two inches from the top, as at a, Fig. ...
123. Hips And Valleys- Hips in slate should be finished the same as described for shingle roofs. If a roll is applied, the simple method shown at Fig. 99, with a short flat wing, will serve all purposes and will give a neat...
Tiles- 127. The clay used in the manufacture of tiles is composed of aluminum and silicic acid, forming two-thirds of its bulk, with about 10 per cent. each of water and quartz, and very small quantities of ...
Glass Roofs- 136. Glass as a roof covering may be used to great advantage for inside halls and passageways, picture galleries, and extensions where ordinary windows cannot be inserted, for dome lights, greenhouses...
Stone Roofs- 143. Stone roofs are not much used at the present time, except for covering small vestibules, porches, turrets, towers, and monumental buildings. They may be flat or pitched. Large slabs are used for ...
Flagpoles- 146. The curve, taper, or entasis of a flagpole may be developed by the following method: the diameter at the base where it emerges from the roof should be about 1/50 of the height, and the diameter a...
Snow Guards- 147. Snow guards made in various forms are used on all kinds of roofs to prevent the snow from sliding down into the gutters, thus clogging them, and causing the water to overflow outside of the build...
Sheet-Metal Work. Uses Of Sheet Metal- 1. The greater part of sheet-metal work used in building construction is employed for the following purposes: 1. For covering and flashing roofs and their intersections, so that the roofs may conveni...
Exterior Sheet-Metal Work. Introduction- 2. The general subject of sheet-metal work for roof coverings, flashings, etc., has been treated in the section on Roofing, and the application of sheet-metal work for ventilating purposes is dealt wi...
Wall Coverings- 4. Wall coverings may be classed as plain and ornamental. Plain wall coverings are used chiefly on buildings intended for manufacturing purposes and for such structures as are erected for temporary us...
Cornices- 13. Sheet-metal cornices are made in such a variety of patterns, in such a wide range of sizes, and are required to be placed in such a diversity of situations, that there must be a great variation in...
14. Cornice Erection On Wood Supports- Fig. 7 shows the parts and joints in a sheet-metal cornice as ordinarily constructed in small sections on a brick wall. The foot molding a is fastened to and supported by a board and wooden lookouts, ...
16. Iron Supports- It is comparatively easy to secure a sheet-metal cornice to a wooden building, or even to woodwork which is spiked to brick buildings; but it is considerably more difficult to properly secure a cornic...
17. Joints In Cornices- Different mechanics have different methods of making vertical joints in cornices; some of these are very neat, strong, and durable, while others should not be tolerated. The only two joints worthy of ...
21. Miters- All miters in cornice work, pediments, and elsewhere may be classed as lap miters or butt miters. Outside miters are made in different ways, but there are only two reliable methods. The first, or lap...
22. Iron-Beam Cornices- In some buildings the ironwork of the first story or store front does not project beyond the wall; and the iron beams, such as those over store windows, often require to be covered with a metal pane...
23. String-Course Cornice- A string-course cornice, or store cornice as it is often called because it is so commonly used over store fronts, is shown in Fig. 15. The lookouts are made of band iron 1/4 in. X 1 1/2 in. and are ti...
27. Soldered Seams- Although it is advisable in all sheet-copper work to solder the seams on the back where they cannot be seen, it nevertheless often happens that some parts must be soldered on the front. The solder doe...
Window Sills, Lintels, And Caps- 28. Window sills are made of sheet metal to represent cut-stone sills. They should be filled in behind with timber of the proper size. The metal sills are usually slipped over the wood backing and sec...
Columns- 32. There are many different kinds of columns and pilasters, and different methods of constructing them. In a general way, however, Fig. 19 illustrates common practice. This figure shows in elevation ...
Fire Doors And Shutters- 33. Wooden fire doors may be covered with any kind of sheet metal which has a high temperature of fusion. Copper and zinc are not suitable for this work; galvanized iron and tin are therefore used, th...
Copings. 34. Wall Copings- The tops of all brick walls must be made water-proof, otherwise the rain will soak into the wall heads and ultimately ruin them. When cheap, light coping stones are used, it is necessary to lay a shee...
35. Coping Blocks- When coping blocks are used to surmount cornices, the flashing\ or wash of the crown may be extended through to the back of the wall, where it may connect to the roof covering, or to a gutter lining, ...
Balustrade Construction- 39. Balustrades, like cornices, etc., are constructed either with wooden or with fireproof supports; the kind to be employed will depend upon the construction of the building. Balustrades, pedestals, ...
Gutters- 42. The varieties of gutters that will be treated of in this section are: eaves gutters, roof gutters, parapet gutters, and belt-course gutters of various materials and for various classes of building...
43. Molded Eaves Gutters- Molded, i. e., ornamental, eaves gutters are often attached to buildings in a manner very similar to that shown in Fig. 30, but while the gutter in this figure is laid with a pitch, such molded gutter...
45. Roof Gutters- Fig. 32 shows a simple form of roof gutter. It consists of a board nailed to the roof and braced by brackets a, a. The board is laid on an incline to form the proper grade, and the lining, which is us...
46. Cornice Gutters- The cornice of a building very often does duty as a gutter also. A wooden cornice gutter, sometimes called a box gutter, as shown in Fig. 34, is employed in the construction of the better class of fr...
47. Terra-Cotta Cornice Gutters- This kind of a gutter, for a fireproof building, is shown in Fig. 35. The terra-cotta slab a of the cornice is backed by brickwork b, upon which rest the I beams c of the roof trusses. The usual angle...
48. Parapet Gutters- A parapet gutter for a building of modern fireproof construction is shown in Fig. 37. The only notable difference between this and the other box gutters, already described, is the fact that the gutter...
50. Wood Tilting Fillets- These fillets are used when the roof is covered with boards. The fillet is shaped as shown at a, Fig. 40, and extends the full length of the gutter. A number of strong cleats b are nailed to the roof ...
51. Corbel-Table Gutter- A corbel-table gutter is shown in Fig. 41. It is supposed to form a belt all around the building, being located about 4 or 5 feet below the eaves. Such gutters, being so far below the eaves, do not ca...
Conductors Or Leaders- 53. Conductors, or leaders, as they are often called, are the pipes which conduct or lead away the water from the gutters. They may be classed as inside or outside leaders. Inside leaders will be trea...
55. Expanding Pipes- Expanding pipes should be used to overcome the trouble from frost. A common form, shown in Fig. 44, is simply a corrugated round pipe. The corrugations allow the pipe to increase enough in diameter to...
56. Square Or Rectangular Leaders- These leaders are made of crimped or corrugated sheet metal, and are often used to obtain a more ornamental effect than is produced by round leaders. They should be supported by ornamental bands in a ...
58. Size Of Leaders- The proper size of leaders, of course, will vary with the climate, the amount of rainfall, and the manner in which the gutter catches the water; but a good safe rule for every-day practice is to allow...
60. Strainers- Every leader opening in a gutter must be provided with a strainer to hold back leaves, twigs, etc., and to prevent birds from building nests in the leaders. The best strainers are those constructed of...
62. Leader Cut-Off- When the leaders discharge into cisterns or tanks, it is advisable in all cases to provide them with cut-offs, so that the water may be discharged to waste or into the cisterns, as desired. Every roof...
Domes And Lanterns- 63. In many parts of Europe it is customary to cover domes, lanterns, cupolas, etc. with sheet lead; but owing to the great variations in temperature which are encountered in the United States of Amer...
65. Ribbed Surface Covering- To avoid leakage on domes by the effects of expansion and contraction, and to prevent any solder from discoloring the copper work, some form of ribbed covering is employed. This requires the use of a ...
66. Horizontal Seams- The best form of horizontal seam that can be made on domes is shown in Fig. 49. A strong cold-rolled copper cleat strip a is nailed to the roof with flat-head brass or copper nails; and the top edge o...
67. Location Of Rolls- In locating the position of the rolls it is necessary to consider the general construction of the edifice, both above and below the dome. The ribs or rolls should not be put up to suit the standard st...
68. Paneled Dome- A paneled dome is shown in elevation in Fig. 52. The lantern under the dome is octagonal in form, with a window a in each side. The dome, however, is round in plan with a panel b located directly over...
69. Flagpole Flashings- These flashings, and those around all other forms of movable finials, require much attention to detail, as they must be made water-tight, and remain water-tight under peculiar conditions. Every flagpo...
70. Flagpole Cap- The top of a pole should always be protected either by a sheet-metal flashing or by a cap. A flagpole cap, with regulation ball, is shown in Fig. 56, which is a detail of the cap shown in Fig. 51. A b...
Crestings- 71. Sheet-metal crestings are of varied design and construction. They can, in fact, be made in any design which is adapted to stone or terra cotta. The most important features to consider in cresting...
72. Attachment- Fig. 57 shows a method of attaching sheet-metal cresting on ridges and hips in such a manner that the nail heads are all concealed. Channel strips a, a of strong sheet metal are bent to the shape show...
Finals- 73. Finials which are less than about 7 feet in height are usually built in the shop to conform with the drawings of the architect, and are taken to the building and erected in one piece. Larger finia...
Interior Sheet-Metal Work- 75. Sheet metal is seldom used in the interior of buildings except for covering walls, ceilings, etc., and even then it is only used for a cheap grade of work, so as to obtain an elaboration of orname...
Materials Used In Sheet-Metal Work. 76. Black Iron Or Steel- This form of iron or steel is used only for the very cheapest roofing and siding, also for interior decoration or fireproofing. No. 26 gauge is generally used. In all cases the sheets must be protecte...
80. Soft-Rolled Copper- This copper is often called hot-rolled copper and is used for lining gutters, valleys, etc. and for pressed or hammered ornaments. The weight generally specified is 16 ounces, and 18 or 20 ounces on s...
82. Tarred Roofing Felt- This form of building paper should be laid under all sheet-metal roof work and gutters to protect the under side of the metal from moisture and deleterious vapors, also to form a soft, protecting cush...
Electric-Light Wiring. Fundamental Principles. Electric Circuits- 1. An electric current may be produced commercially by means of either a primary battery or a dynamo-electric machine. The elementary form of battery is simply a vessel A, Fig. 1, containing alkaline ...
5. Ohm's Law- The strength of an electric current in any circuit is directly proportional to the electromotive force developed in that circuit and inversely proportional to the resistance of the circuit; i. e., is ...
The Ampere- 7. The strength of an electric current can be described as a quantity of electricity flowing continuously every second ; or, in other words, it is the rate of flow of electricity just as the current e...
The Ohm- 8. The unit of electrical resistance, now universally adopted, is called the international ohm. One international ohm is the resistance offered by a column of pure mercury 106.3 centimeters in length ...
The Ohm. Continued- Rule To find the resistance of any length of wire, divide that length in feet by 1,000, and multiply by the figure giving the resistance of that wire per thousand feet, as found in Table 1. Example ...
The Volt- 13. In mechanics, pressures of all kinds are measured by the effects they produce; similarly, in electrotechnics, potential is measured by the effect it produces, and the volt, or practical unit of po...
Drop Or Loss Of Potential- 14. Referring again to water flowing in a pipe, though the quantity of water which passes is the same at any cross-section of the pipe, the pressure per square inch is not the same. Even in the case o...
Wiring For Incandescent Lights- 16. In Art. 1 reference was made to two methods of current generation, namely, by means of batteries and by dynamo-electric machinery. For electric lighting, the only practical method is the latter. C...
Conductors- 17. Conducting cables or wires for any system of electric house lighting are always arranged as a closed circuit; that is, one wire must be provided to convey the current to the lamps, and another one...
House Fixtures- 20. The incandescent lamp, Fig. 9, is provided with a composite base, made to fit in a corresponding socket connected with the house wiring. The filament F is made of a thread of carbon, which materia...
23. Conventional Symbols- In the diagrams of lighting circuits in the following pages, the symbols given below will be used. See Fig. 14. Symbol a is a safety plug, or cut-out. Symbol b is a wall switch. Symbol c is a 32-ca...
Safety Cut-Outs- 24. Safety cut-outs are devices that break a circuit before a wire becomes sufficiently heated by the passage of a current to cause danger of fire. They are also used to protect lamps. Fig. 15 shows a...
Switches- 30. A switch is an appliance interposed in an electric circuit for the purpose of readily, and without danger, opening or closing that circuit. For large currents some form of knife switch, such as th...
Connections For Incandescent Lamps- 37. There are three methods in general use by which electric incandescent lamps are connected in circuit, namely, the multiple-arc, or parallel, system, the multiple-series system, and the three-wire ...
38. Multiple-Series System- Fig. 27 shows the multiple-series system. Two or more lamps are arranged in series groups, and these groups are connected in parallel between the conductors a b and c f. Manifestly, when one lamp is b...
39. Three-Wire System- Fig. 29 shows the three-wire system. The two dynamos d and d1 are connected in series, the positive lead of one being joined to the negative lead of the other. From the remaining terminals of the mach...
40. Flexible Two-Wire System- For a local installation the three-wire system is not a good choice, as two dynamos must be constantly running; but when there is a three-wire city supply available, a combination wiring for the two s...
Methods Of Wiring. 42. Feeders And Mains- Feeders are conductors supplying current to single terminal points or distributing centers, running directly from the source of current to those points without any branches or other connections throug...
44. Connections For Equalizing The E. M. F- Fig. 32 shows two methods of preserving equal E. M. F.'s at all points. At (v) is shown a loop circuit, in which the drop from the dynamo terminals to any lamp is the same. It will be seen that the le...
Interior Wiring- 49. There are three methods of running electric-light wires, namely, cleat work, molding, and concealed work. Cleat work is used in such places where appearance is of little consequence, as in factori...
56. Concealed Work- This is the most satisfactory method of wiring a building, and consists in providing a complete network of tubing, laid beneath the plaster of the walls, between partitions and under floors, to receiv...
59. Street Junction Boxes- When connection is made between the inside wiring and the street main, a junction box such as that illustrated in Fig. 49 is employed. The three-wire system will probably be used on account of the eco...
Wiring Calculations- 60. The size of wire required to supply current to any group of lamps depends on the number of lamps, each of which takes a certain average current. The following table gives the value of this current...
Wiring Calculations. Part 2- Example A group of 41 lamps, 16 candlepower, is to be set 1,500 feet from the dynamo on a 110-volt circuit. What diameter of conductor should be used when the drop is to be 5 volts ? Solution The n...
Wiring Calculations. Part 3- Solution The line loss is 3 volts = E; the number of lamps is 24 of 16 candlepower, and 3 of 32 candlepower, equivalent to a total of 24 + 6 = 30 of 16 candlepower = N ; the distance is 75 feet = F. ...
68. Heavy Conductors- It frequently happens that a very large wire is necessary for a feeder, and the resistance is not given in the wire tables, so that the formulas already considered will not apply. In this case, the ar...
71. Size Of Conductors For Three-Wire System- The method followed in calculating the size of conductors for the three-wire system is based on the same laws as for the two-wire system. When the two sides of the three-wire system are balanced, with...
73. Arrangement Of Circuits- A group of different methods of wiring for the two-wire system is shown in Fig. 51. It will be noticed that the closet A is so placed that the lamp feet of the various branch circuits are approximatel...
74. Wiring In Large Buildings- For a large building, separate circuits may be run to the top floor up two or more vertical corners. One of these circuits is shown in Pig. 52. The terminal board of the dynamo is shown at s, correspo...
Bellwork. Bell Construction And Operation. Apparatus For Bell Circuits- 76. In nearly all electric appliances, particularly in those we are about to describe, the electromagnet is an all important feature. It was early discovered that when a current of electricity circula...
Arrangement Of Bell Circuits- 85. A simple bell circuit is shown in Fig. 63. A battery of two Leclanche cells c, c connected in series furnishes current to the bell b, located at any part of the house, and the push button p is pla...
Running The Wires- 91. The directions given in Arts. 49 to 55, for running wires, apply to bellwork in some degree, but, in this work, the wires may be laid side by side, provided they are properly insulated. All wires ...
Annunciators- 93. When a number of push buttons is used in a call-bell system, as in the different rooms of a house or hotel, it becomes necessary to provide some means of determining 6C which of these buttons has ...
95. Wiring For Simple Annunciator- A wiring diagram for a simple annunciator system is shown in Fig. 75. The pushes 1, 2, 3, etc. are located at convenient points in the various rooms, one terminal being connected to the battery wire b...
96. Wiring For Return-Call Annunciator- In Fig. 70 is illustrated a return-call system requiring one battery wire b, one return wire r, and for each room one leading wire l1, l2, etc. The annunciator board is divided into two parts, the upp...
98. Wiring For Elevator Annunciator- The wiring for an elevator annunciator is not materially different from that used in the simple annunciator described in Art. 95. A single No. 14 wire, b, Fig. 78, is connected to one pole of the batt...
Special Electric Fittings. The Electric Door Opener- 99. In apartment houses the mechanical door opener is frequently replaced to advantage by one operated electrically. A view of one of these is given in Fig. 79, which shows the position of the differe...
Burglar Alarms- 100. Automatic switches may be placed on windows and doors, in connection with alarm bells, to indicate when entrance into a building is being forced. There are two methods of installing these alarms:...
Electric Gas Lighting. Burners For Parallel, System- 102. In the application of electricity to gas lighting, a spark is caused to pass between two conductors, placed near the burner, at the same time that the gas is turned on. In the parallel system of ...
Arrangement Of Lighting Apparatus- 106. The apparatus used in electric gas lighting, on the parallel system, consists of a battery of about six cells, of a type giving a strong current, such as the Fuller Mercury Bichromate battery, an...
Apparatus For Multiple-Lighting System- 109. The multiple, or series, system of gas lighting is used in large halls where many lights are installed in groups. A fixed spark gap is used at each burner, both of the points being insulated from...
A Series Of Questions And Examples- Relating to the Subjects Treated of in this Volume. It will be noticed that the questions and examples contained in the following pages are divided into sections corresponding to the sections of the ...
Stair Building. (Arts. 1-61. Sec. 11.)- (1) (a) State a method of altering the stairway shown in Fig. 21. (b) Show how to lay out an easement curve for a stringer. (2) (a) Define riser, tread, and step, (b) What is meant by flight and by l...
Ornamental Ironwork. (Arts. 1-78. Sec. 12.)- (1) Describe the general construction of a small iron office. (2) What combination is sometimes made with elevator enclosures? (3) What characteristic renders iron of particular value as a building ...
Roofing. (Arts. 1-148. Sec. 13.)- (1) Describe the methods of constructing stone roofs. (2) What is asbestos, and where is it found? (3) What are snow guards used for? (4) Describe the manner of shingling conical towers. (5) Where...
Sheet-Metal Work. (Arts. 1-83. Sec. 14.)- (1) Describe, and show by sketch if necessary, a suitable sheet-metal finish at the corner of a building whose walls are covered with corrugated sheet iron. (2) Clearly and briefly describe, with ske...
Electric-Light Wiring And Bellwork. (Arts. 1-110. Sec. 15.)- (1) What is Ohm's law? (2) How would you define drop of potential? (3) What are the three methods of connecting incandescent lamps in circuit? (4) What are the units employed in measurement of cu...