This section is from the book "A Treatise On Architecture And Building Construction Vol2: Masonry. Carpentry. Joinery", by The Colliery Engineer Co. Also available from Amazon: A Treatise On Architecture And Building Construction.
On this ledger board the floorbeams n of the second story are laid, each beam being slightly notched at i, on its under side, in order to bring the tops of the beams to an even alinement. The second-story beams are not nailed to the ledger board, but are securely spiked to each stud, on the same side of the stud as the beams in the tier below.
175. The beam shown at j is double the thickness of those at n, as it is a trimmer beam and carries the header / and the weight from the tail-beams m. This header and trimmer forms one end of the stair well, or opening, and if there is to be a similar opening in the third, or attic, floor, great care must be taken to place the attic-floor header perfectly parallel and plumb over this one, as trouble will arise when the stairs are built unless such care is observed.
176. The second-story beams being laid, we may now start the tier above, but if this third tier is simply to be of ceiling beams, and the attic story is not to be finished off in rooms like the rest of the house, we will first lay the wall plate o, which is usually composed of two pieces of studding nailed together and so lapped that the joints of any two lengths are as far apart as possible.
This plate is laid along the top of the wall and securely nailed to each stud; the attic beams are then notched over it in the same manner as the first tier of beams was notched on the sill, and securely nailed in place.
Our exterior frame is now fairly complete from sill to plate; and while the above described work has been in progress, the partitions have been erected, the first, or rough, floors laid on the interior, and the window and door openings framed, and the frame sheathed in, on the exterior. In fact, it is sometimes necessary to erect the main partitions at the same time as the outside walls, in order to provide a support for the interior ends of the floorbeams.
177. The studs qq, supporting the partition plate r, show the position of a principal partition which supports the ends of the second-story beams m and n, and the continuation of this partition in the second story supports the interior ends of the attic beams p.
The plate r on the top of these stud partitions is generally composed, like the main wall plate o, of two pieces of studding nailed together, and though one thickness would be strong enough for all practical purposes, the two pieces are preferable in order to secure the same amount of shrinkable mate-rial under each end of the beam, and as the ledger boards on the outside are 4 inches deep, the plate in the interior is made 4 inches deep, also.
178. The framing of the openings is shown at E, where the studs on each side of the opening are doubled and spiked securely together to act, practically, as one piece. The head and sill of the opening, if it is a window, are also composed of doubled studs, and where the window is over 3 feet in width, the top should be trussed, as shown at s, and described in detail in Art. 129. The double studs at the sides of the opening are carried through to the plate, and if there are to be two openings, one over the other, the upper one alone need be trussed, unless there are floorbeams, or other details, which will concentrate too much weight over the opening. This is the case at E, and the window head is trussed to carry the load of the two beams t to the double studs at the sides.
179. In laying out the studding of the exterior walls of a building, two methods are used; one where the double studs at the sides of the doors or windows are first placed in position, and the single intermediate studs are spaced 16 inches on centers between them; and the other method, in which the studs are spaced throughout at the uniform distance of 16 inches on centers, after which the door and window openings are sawed out and the studding framed to suit.
The former of these methods is shown at E and the latter at F, where two studs u u have been cut out and the adjacent ones vv have been doubled, the space between them being trussed to carry the floorbeams in the same manner as at E. This leaves an opening of 4 feet between the centers of the studs at the sides of the opening, and, as this is more than we require, we limit the opening by the stud g' cut in between the truss and the sill; or, if the plan requires the door to be further to the right, we can cut in two studs and center the opening at any point desired.
180. Sheathing is composed of 7/8-inch boards, matched or unmatched, and planed on one side to give them a uniform thickness. In balloon-frame buildings they should always be laid diagonally, as it is upon the bracing effect of the diagonal sheathing that the building depends for its strength. When the corner posts of a building are set and plumbed, two pieces of sheathing are then nailed on its adjacent exterior sides with their lower ends spiked to the sill, as shown at g, and as the studs are successively set they are braced on the outside by similar sheathing boards, and every sixth or eighth stud is braced temporarily from behind, as shown at h. The sheathing is then carried over the whole side of the building, no attention being paid to door or window openings, except where a sheathing board projects a few inches over an opening; it is permitted to remain so, and the next board to it in the course is started from the other side of the window.
This is illustrated at G, where the dotted lines show the outlines of the window opening, and the full lines indicate the sheathing boards as they are laid up on the studs, to each one of which they are nailed with two tenpenny nails. At w is shown the sheathing sawed out to fit the opening, the boards being cut flush with the face of the studs.
181. When the sheathing is nearly completed and the first, or rough, floors are laid, the structure is ready to receive the first timbers of the roof.
The pitch of the roof in this case is rather steep, being 17 inches rise to 12 inches run, and the plumb-cut of the rafters will be found by laying the steel square on the side of the timber with 17 inches of the blade and 12 inches of the tongue on the line of what is to be the top edge of the rafter; the outside line of the blade will then mark the plumb-cut, as explained in Art. 153. The foot-cut and overhang for the eaves are measured and cut as explained in Art. 153, and when one rafter is finished and sawed complete, it is used as a templet to mark and cut all the others by, before the framing of the roof is commenced.
The first rafters set are those forming the end of the gable at x, and the ridge plate z is composed of a wide piece of \\-inch material beveled on its upper edge, as explained in Art. 164. To this ridge plate the rafters x are spiked on opposite sides, and somewhere near the other end two other rafters are similarly spiked to hold the ridge plate in position. The rafters y and y' are so placed as to foot on the plate o adjacent to the valley rafters w' and v', which are then placed in position, having been previously cut to the required lengths. The valley rafter w' is set first, and then the valley rafter v' is securely footed on the plate and spiked against it. The header plate t' is then spiked between these two valleys at the point where the slope of the smaller gable is to start, and after t' is securely nailed to the two valley rafters, the first two of the small gable rafters s' may be set in position, securely nailed to the header plate t' and spiked through the ridge plate u', whose other end is nailed into the angle formed between the two valley rafters w' and v'.
The ridge plates z and u' and the header rafter t' must, of course, be perfectly true and level, and when set they must be so securely fastened that subsequent operations will not force them out of line. The jack-rafters r' and p' may now be set in pairs, one each side of the valley rafter w'. This is done in order that the thrust may be the same on each side of the rafter at the same time, for, if we laid all the jack-rafters on one side at the same time, it would cause the valley rafter to bulge and curve out of line and prevent the opposite rafters from fitting properly.
For this same reason great care must be exercised in setting the jack-rafters q' as, in driving them close into their places, we are apt to cause the header rafter t' to bulge inwards, and out of line with the gable rafters s' above.
182. After all the rafters are in place, the boarding of the eaves is laid, as shown at o', and above this boarding the shingle laths d' are laid, with a clear space between them equal to the exposed length of the shingles. The spacing of the shingle laths is measured from the lower edge of the lowest roof-board at the eaves, and the spaces are measured off up the rafters to the ridge, where any difference in exposure of shingles can be taken up by increasing, or slightly diminishing, the width of the ridge boards when they are laid. Side sheathing, roof sheathing, and shingle laths must be nailed to each stud, or rafter, with two nails for boards and one nail for shingle lath; where a joint occurs in a length of board, or shingle lath, it must be in the center of the rafter, or stud, and both joining ends must be securely nailed to the supporting timber.
183. The rough framing of the building may now be considered as complete. The skeleton is up and covered in with its sheathing; the floorbeams, or joists, are in position, and the rough, diagonal flooring is laid; the partitions dividing the interior are all studded, and the openings for doors and windows have all been framed and sawed out through the sheathing.
It now remains for the carpenter to lath the partitions, cross-fur and lath the ceilings, nail on the grounds which are to secure the wainscot, trim, picture moldings, etc., on the inside of the building, and to set the frames for the windows and doors, apply the outside casings, put on the clapboards, or siding, and shingle the roof on the exterior of the building; his work will then be practically complete, until after the joiner and painter have finished. In many localities, lathing is executed either by special lathers or by plasterers.
184. Before the walls are lathed, it is sometimes desirable in buildings where the ceiling is high, to provide a line of bridging between the studs, as shown at h' the bridging tends to make the walls stiffer sidewise, and the studs are thus prevented from warping.
This nogging consists of pieces of old or broken bricks, laid in lime mortar so as to completely fill the spaces between the studs and up to the top of the beams, as shown at a, Fig. 73, thus closing not only a passageway for cold drafts from the cellar, but also against the rapid spread of flames in case of fire. The brick nogging may, with advantage, be continued up three courses higher than the beams, between the studs, which will prevent drafts at the floor level, caused by the circulation of the air through the channels between the studding. Sometimes, where brick is not convenient, short pieces of 2" X 4 " studs are filled in and spiked to the sill and beams.