CHAPTER VExterior Covering and Finish

49. Sheathing or Sheeting.—After the frame work of a building is erected and the openings made in the frame for windows and doors, the sheeting is to be placed. Sheeting is placed either horizontally across the studs or diagonally, sometimes both ways, depending upon the specifications of the architect. The diagonal is somewhat stronger but is more expensive. The horizontal is satisfactory upon ordinary frame dwellings, especially where the building is braced at the corners by studs cut in diagonally, or by sheeting placed diagonally at the corners as inFig. 90.Such sheeting should be matched and well nailed with two 8d nails to each stud. Building paper should be placed upon the sheeting to further protect the interior from cold.

Fig. 90. Sheathing

Roof sheeting for shingle roofs may best be of unmatched boards spaced about 2" apart. For slate, matched stock should be used and this covered with a tar or asphalt paper.

Fig. 91. Setting T-bevel for Roof Boards

In making the face cut on roof boards for hips or valleys the framing tool or the T-bevel may be made use of, being set to the complement of the angle used in making the side or cheek cut on jack rafters. The complement angle in this case equals 90 less the angle of the side cut of jack. Or, if the framing square is to be used, the same numbers used in making the side cut of the jack will be used in laying out the face cut of roof boards, with the scribing being done along the tongue instead of along the blade as in the case of the side cut.

A second T-bevel may be set as inFig. 91, the beam being placed across the edge of the jack and at right angles to it, with the blade adjusted to the cheek or sawed surface of the jack which is to fit against hip or valley rafter. A framing tool might be used.

Carpenters more frequently, however, get the angles for sawing roof boards by laying the board to be cut out over the hip or valley rafter, then sawing along the side the rafter as inFig. 92.

In warm climates, weather boarding is often applied directly to the studs, no sheeting being used; the frame being strongly braced at the corners.

50. Scaffolding.—Cornice is placed after sheeting. To do this advantageously it is necessary to erect scaffolding or staging.Fig. 93illustrates a common type. Stock 2" × 4" is used for the uprights, and 1" × 6" for the horizontal members and braces or stays. Planks are placed upon these horizontals as shown.Fig. 94illustrates a substitute for staging, a scaffold bracket upon which planks are laid.

Fig. 92. Sawing Roof Boards

Fig. 93. Scaffolding

Fig. 94. Scaffold Bracket

51. Cornice.—Cornices are generally classified as open or skeleton, and box, Figs.95and96. Each of these types will be found constructed in almost endless variety of forms. The illustrations shown will serve the purposes of this text. The student should familiarize himself with the various common forms, details of which may be got from any good, modern book on building details.

Fig. 95. Skeleton Cornice Fig. 96. Box Cornice

In making the various cuts on cornice work, a miter-box must be available for mouldings. The old type of wood miter box, with the various necessary cuts laid out in its sides is satisfactory. Some experimenting will be necessary upon the part of the beginner to determine the manner of placing the moulding in the box to give the correct cut.

The cuts for the plancher, which rests in the planes of a hipped roof and which must be membered around a corner are determined in a manner similar to that described for roof boards,Sec. 49, from the cuts of the jack rafter cheeks.

Fig. 97-a. Skeleton Cornice

Fig. 97-b. Box Cornice.

Fig. 97illustrates the manner of "framing in" the lookouts on' gables where a skeleton cornice is used. Also there is illustrated the manner of placing lookouts in gables for a box cornice. Unless the cornice is quite wide, these blocks are merely fastened to theunderside of the roof boards at intervals of 3 or 4 feet. The depth of these blocks will depend upon the manner of framing the tail ends of the rafters.

Metallic gutters made to assume the form of the crown mould, no wood crown mould being used, will be found in common use upon ordinary house construction. A fall of ½ inch to every 10 feet is usually given gutters.

52. Raked Mouldings.—In all cases where a moulding resting in one plane, as crown or bed moulding at the eaves, is to be membered with moulding swung up out of that plane, as up a gable, one of two things must be done to make the surfaces of the mouldings match or member properly at the joint: (1) The moulding at the eave may have its top edge tipped forward until its top edge lies in the same plane as the top edge of the corresponding gable moulding; (2) a moulding with a new face may be worked which will member with the eaves moulding when their reverse surfaces are fitted to the fascia or, in case of bed moulding, to the frieze.

Fig. 98. Laying out Gable or Raked Moulding

To member by means of the second method proceed as follows: (1) Make a full sized drawing of a cross-section of the moulding,Fig. 98.(2) Draw a number of lines thru the more important reference points of the moulding at an angle equal to the pitch of the gable. (3) Draw horizontal lines thru the points of reference and erect a perpendicular thru these passing thru the back of the mould asA-B. (4) Lay off a lineC-D,Fig. 98, perpendicular to the oblique lines. (5) Using the linesA-BandC-Das reference lines, transfer the distances of the various points on the eaves moulding, measured horizontally fromA-B, to pitch lines measured obliquely. A curve traced thru these points will give the shape of the moulding required for the gable. Since this moulding would, in all probability, have to be worked up especially for any particular job, this practice is not followed except upon large or important work. Cornices are usually designed so as to avoid such work.

Fig. 99. Miter Box for Raked Gable Moulding Cut at Eaves

Fig. 100. Miter Box for Plumb Cut of Gable Mouldings

Figs.99and100illustrate two miter-boxes constructed for use in cutting rake mouldings in gables.

In making the miter cuts on mouldings of the eaves, the horizontal members, no special box is needed. The moulding will be set on the far side of the box, upside down. The box will have the side cuts perpendicular to the top edge and the angles across the top edges will be determined by the miter of the plate, sill, or corner of the building. On a square cornered building this miter will be one of 45, 12" and 12" being taken on the square. Two cuts of each kind, but reversed, are made in each box so that the moulding for each side of each gable may be readily cut. On the octagonal building 5" and 12" would be used in laying out the miter, with scribing done along the 5" member of the square.

For the miter cuts of the rake or gable member, special boxes would best be constructed. For the cut of the gable memberwhere it joins the eave moulding: (1) Lay off across the top of the miter-box, right and left, the miter of the plate, sill, or corner of the building. (2) Down the sides of the box lay off the slanting lines as shown inFig. 99, at angles determined by the plumb cut of the common rafter. (3) Lay the moulding in the box as indicated by the cross-section,Fig. 99, being careful to keep the backs of the mouldings adjusted to the side and bottom of the box. A good plan is to drive a nail or two in the bottom of the box against which the moulding may be made to rest, once the proper position is determined by trial.

For the plumb cut of the gable moulding, (1) lay off lines across the edges of the box as inFig. 100, using on the framing square the numbers which give the plumb cut of the common rafter. Lay off a right and a left cut as shown. (2) Square these lines down the sides of the box and saw. (3) The moulding will be placed in the box as shown in the cross-section view ofFig. 100, especial care being taken to have the backs of the mouldings adjusted to the back of the box.

Manifestly, one box may contain all these cuts to advantage instead of having three boxes.

These cuts, Figs.99and100, serve in cutting the miters on ends of the gable fascia. A little consideration will make clear the remaining cuts upon ordinary cornice work.

In splicing mouldings, corner boards, etc., a mitered joint is best and should be made so as to shed water from the joint,Fig. 101.

53. Shingling.—The reason for placing cornice before base or window frames, etc., is to allow the workmen to work inside should inclement weather overtake building operations at any time. Shingling, therefore, will follow cornice work.

Fig. 101. Spliced Comer Boards and Moulding

The amount of shingle to be exposed to the weather will depend in general upon the pitch of the roof. In no case should this exposure exceed 5 inches. The shingle most used is 16 inches long, and each shingle should lap two courses beneath it. The usual amount of lay is from 4" to 4%", by quarters. When nearing the ridge or comb of a roof in shingling, the dimensions used on the main body of the roof should be increased or decreased so as to make the final layer show under the comb or ridge or saddle boards properly. The worker should begin such calculations when within about four or five feet of the ridge so that changes of exposure of the different layers may not be noticeable and so that the line of shingle butts may be kept parallel with the ridge.

Fig. 102. Beginning Course

The first layer of shingles should be a double one with joints properly broken, and with the butts projecting over the crown moulding about 1½" to 2". Lay the shingles at the gables first, then at intervals of about ten feet. Stretch a chalk line between these fastening it to the butts by shingle nails driven into the butts,Fig. 102.

The remaining courses may be laid by means of a straight-edge or by means of a chalk line. Both practices have ardent advocates. Where a straight-edge is used, it is usually a piece of lap siding or clapboard, and is held in place by being lightly tacked.

Fig. 103. Shingling. Toe Hold

In using the chalk line a man for each end is required. The line is chalked and snapped for three courses at a time. The mechanic, after a little practice, is able to keep the butts of the shingles straight and to sight them so that they shall follow the chalk line mark. On long courses a third person may be utilized in chalking and in laying shingles. In chalking, this person holds the line to the roof as sighted by an end man and the snapping is done on each half of the line.

The chalking of a line so as to conserve the chalk is one of the tricks of the trade which must be mastered early. It consists inrotating the chalk about its hemispherical axis while being worked backward and forward along the line, the line being held between the chalk and the ball of the thumb. Otherwise the line would soon sever the chalk.

Fig. 104. Shingling. Toe Holds

Cut nails should be used in preference to wire nails because of their greater rust-resisting quality. Dry shingles should not be laid tight together, ⅛ inch between is not unusual with dry shingles. It is best to split shingles over 10 inches wide before laying them. Each shingle should have at least two nails, the average is two nails for every four to six inches of shingle.

Scaffolding for roof work, or toe hold, is usually constructed by nailing shingles to 2" × 4" as shown in Figs.103and104. Other forms are equally common. Apparently the holes left by the nails used to fasten the toe hold to the roof would cause a leak in the roof. To avoid any such danger, tho such danger is slight because of the swelling of the wood fiber upon the application of moisture, the shingles having such holes are driven down the roof slightly by striking their surfaces a glancing stroke.

54. Shingling Hips and Valleys; Flashing; Saddle or Comb Boards.—Hip and valley shingles are usually sawed to shape beforebeing taken to the roof, the face cut being the same as that used across the face of the roof boards and plancher members intersecting about a corner of a hipped roof where plancher lies in the plane of the roof. The cut across the edge of such shingles is made square to the face.

Fig. 105. Shingle Tins Fig. 106. Valley

Of the many ways of protecting the intersection of hip shingles when in place upon a roof, the simplest is that of employing tin shingles. Such shingles should be of sufficient length to allow the corners to be turned under as shown inFig. 105, and still extend far enough under the next course of shingles to permit the nails holding the tins to be covered. It is not good practice to nail thru these tins after the roof has been covered, that is, to place these tins after the roof has been shingled because the action of the weather "lifts" the nails when exposed thus.

Valleys are covered with a strip of metal to a width of 20 inches. Upon steep roofs and short valleys this width may be reduced to16 inches. Space must be left between the edges of valley shingles as shown in Figs.106and107. The amount will depend upon the length of the valley and the steepness of the roof. For a ½ pitch with a length of twelve to fourteen feet of valley, the space at the top of the valley may well be 1 inch to each side of the valley center line, widening gradually toward the lower end to 2½ inches to each side. Chalk lines snapped upon the tin or other metal forming the valley indicate the location of shingle edges. Nails in valley shingles should be kept well back from the valley edge of the shingles.

Fig. 107. Shingling Valley

Flashing consists in placing tin shingles or other material about the members making up a joint so that the joint shall "turn water." Counterflashing consists in placing a double layer of tins in such a way as to doubly insure turning water from a joint.

Fig. 108is an illustration of flashing where shingles meet lap siding. Shingle tins are forced under the siding on one side and either under or over the shingles, several inches of lap being allowed all about.

Fig. 109illustrates a counterflashed chimney. A layer of tins is placed as in flashing against siding except their top edges are notinserted. Over these tins a second layer is placed as shown, the top edges being inserted ¾" between the layers of brick, the mortar being raked out so that this can be done. These turned edges are held in place by the insertion of a wedging nail or tack, after which the cracks are filled with cement, or better, an elastic roofing composition.

Tins should be carried high enough to prevent drifted snow from entering; 2½ or 3 inches at the narrowest place.

Fig. 108. Flashing Fig. 109. Flashed and Counter-flashed

Saddle or comb boards are of various forms. They are used to give the ridge a finished appearance and to turn any water which might happen to strike thereon; also to hold the last course of shingles in place. A simple form is obtained by creasing to the appropriate angle a strip of tin eight inches in width. Place this on the ridge and nail its edges at intervals of 3 or 4 inches. Where boards are used, one board should overlap the other and extend a half inch beyond to turn water from the joint so made. Galvanized ridge rolls may be purchased in stock styles.

55. Finishing Exterior Walls.—With the roof completed, side walls are next covered except where porches are to be attached.

Fig. 110illustrates the manner of constructing an exterior wall having a water table and lap siding, also the relation of the various parts of an exterior wall.

Fig. 110-a. Interior Wall Detail

Fig. 110-b. Exterior Wall Detail

A belt course is sometimes used between the first and second stories of a building. Such a course is often constructed like the water table. Like the water table or base, this belt course is furred out in order to throw the course into greater relief. In case this furring is not done, the lower edge of the belt board must be rabbeted to receive the top edge of the siding. Frieze boards, too, are frequently furred instead of being rabbeted. More elaborate belt courses are common.

Fig. 111. Leveling Door Sill

Building paper should be stripped about the openings for doors and windows before the frames are set, to insure warmth; also about corner boards and cornice.

Corner boards and casing edges should be very slightly beveled so that the siding may take a slight squeeze as it is placed. Care in setting frames and in making casing edges true will insure a saving of time in placing siding.

56. Setting Window and Door Frames.—Two men usually work together in setting frames, as in fact they do on much other carpentry work. In setting door frames on outer walls (1) the rough floor, etc., must be cut away so that the top of the sill may rest on a level with finished floor when that is in place. (2) When this is done the door sill is carefully leveled,Fig. 111, and shingle points inserted under the sill where needed to give solidity and support. (3) The casing is given a nail close to the sill at each side of the frame and (4) the sides of the jambs, are plumbed and the casings finish nailed. If the work is carefully done the frame should be square.

Where heads of several windows are a given distance from the floor, a stiff stick may be cut this length and used in placing windows in position for height. The window sills will be leveled as are door sills; the jambs are plumbed,Fig. 112, and casings nailed at intervals of about a foot.

57. Siding.Preparatory to siding, a siding stick should be made. Such a stick is made by planing parallel edges upon a piece of Y% inch stock about 1 inch in width. Upon this stick marks will be made which will indicate the spacing of the siding; these marks being transferred to corner boards and casing edges,Fig. 113. To lay off this stick a given space is taken, water table drip cap to the lower edge of a window sill for example. (1) This space may be transcribed upon the stick easiest by setting the stick upon the drip cap and against the casing edge, marking under the sill upon the stick. (2) This space is "stepped off" by means of a pair of dividers set to the amount of exposure desired. Exposures will run from 4¼ to 4¾ inches on ordinary lap or bevel siding.(3) Should there be a remainder, and there almost always is, the exposure must be increased or decreased, whichever is necessary, an amount sufficient to give an equal or even number of divisions. In practice this amount is found by stepping off as suggested and then making necessary adjustments by guess and again stepping. This is continued until the desired result is attained. The difference is thus divided equally over the whole space instead of over the last courses as in shingling.

In a similar manner a stick, or another space of the same stick is laid off and stepped for the space between the bottom of the window sill and the top of the drip cap above the head casing of the window, etc. On long lateral spaces this stick will be used to keep the lower edges of the boards in position between the casings, by transferring its marks to the building paper, stepping down from one of these marks with a pair of dividers to the lower edge of the siding board being placed. (4) A bunch of siding boards should have one end of each sawed square across the face, but sawed under on the back side slightly so as toinsure a fit on the surface. (5) One end is next fitted, with block plane if necessary, after which (6) the length is marked by turning the board upside down and marking on the lower edge of the board, which is uppermost, with a knife,Fig. 114.Another way to mark length is indicated inFig. 115.This tool is called a siding hook or tool and this method possesses the advantage of caring for any lack of squareness in the frame or trim.

In nailing, care must be taken to place the nail so that it shall pass thru both boards where lapped. Under windows it will be necessary to trim off part of the upper edges of the siding boards. Saw kerfs at either side of the part to be cut, and a sharp, deep knife scoring along a straight-edge should be used to outline the part to be removed. To determine the amount to be removed, set the dividers to the amount of spacing used for the boards in the space under the window, plus the depth of rabbet, or groove in the under side of the window sill into which the upper edge of the siding board must fit. Set off this amount on the siding board from the butt or under edge at each end of proposed cut, and connect with straight-edge; scoring with knife.

Fig. 116. Siding Circular Tower

Occasionally the carpenter is called upon to side a circular tower or rounded corner of a building. That the lower edge of each board may rest in a horizontal plane it will be necessary to shape that edge before applying the board to the side of the building. Todetermine the amount of curvature to give such an edge proceed as follows: (1) Plot a curve to represent the plan of the tower,Fig. 116.Draw this upon a scale sufficiently large and make use of accuracy such as will insure a result equal to the requirements of the occasion. (2) Draw the lineA-Bof indefinite length. (3) Place a section of a clapboard in the position it will have on the sheeting, as atabc,Fig. 116, and (4) extend a line along the face surface to meetA-B. (5) With a radius equal toB-Cdescribe an arc withBas a center which shall cut the siding board as shown, taking an equal amount off the edge at each end.

Occasionally it becomes necessary to fit a casing against a sided wall. This casing is scribed as indicated inFig. 117, a pair of sharp dividers being made to follow the contour of the wall with one point while the other marks or scribes the casing. A saw will be used to cut to these lines, sawing under slightly to insure a fit at the face.

Fig. 117. Scribing against Irregular Surface

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