(Fig. 25.) For instance, in our case the amount of horizontal wood in the outer wall from the rigid underpinning to the bottom of attic joists will be,— the sill at six inches, the girt at six inches and the upper part of the ledger board above its nailings at two inches,—in all fourteen inches of shrinkable wood. 1f the inside partitions were set on a two-inch sole resting on the under floor in each story, there would be in the inside wall, from the rigid piers in the cellar to the under side of the attic the girder at ten inches, the two tiers of floor beams with under floors at eleven inches each, and two soles and two caps at two inches each,—making in all forty inches of wood, the shrinkage of which would amount to an inch and a half or more as against a probable half-inch on the outside walls. The result, when the house has become completely would be that the inner end of the floor beams would be an inch or more lower than the outer end, enough to crack the plastering, and make doors bind in the cross-walls of the second and third stories. The remedy for this, is to let the studs of the first story stand on the girders, and the studs of the second story stand upon the cap of the first story partition, and so on, so that the floor timbers do not form a part of the vertical frame. (Fig. 26.) This will give an amount of horizontal wood equal to the girders at ten inches, and the two caps at two inches each, making fourteen inches in all, about equal to the horizontal timber in the outside frame. Partitions running through two or more stories which do not carry floor beams should be built in the same way. Partitions which have no corresponding partitions under them will often occur and will be found in two conditions, those running parallel with the floor beams and those running across the floor beams. In the former ease it will be necessary to set two floor beams under the partition spaced far enough apart to give a good nailing for the ends of the upper floor boards. In the latter case it will be necessary only to lay down upon the under floor a sole two inches thick by the width of the studs.
An important matter in relation to the levelling of the floors is to see that all measurements for sizing down of the timbers are made from the top of the timber, so that the floor will be level on the top and any inequalities in the depth of the joists can be taken up in the furring. A half-inch will usually be enough to overcome the differ ences in the depth of the joists so that a series of ten-inch joists should be set with their tops nine-and-one-half inches above the girder or partition cap upon which they rest.
Roofs. As soon as the attic floor is on, the roofs will be raised. In ordinary country houses the roof should be supported where pos sible by the interior partitions where they extend down to first floor girders over basement piers, in which case no complicated framing or truss work will be required. The ordinary form of roof consists of a series of rafters supported at the bottom by the plate of the house and at the top by the ridge pole. Intersecting roofs are supported by larger timbers called valley rafters and these should always con tinue up to the ridge. If the rafters are over eighteen feet long it will be necessary to support them near their center, this is done by partitions or by collar beams spiked across from rafter to rafter.
(Fig. 27.) In large buildings they are supported by purlins resting on trusses or on posts. The spacing of the rafters varies from sixteen inches to two or three feet, twenty inches being the most usual.
For any roof of less than 30-foot span with the plate securely tied, no interior supports will be needed, and above this span, purlins should be used. The size of rafters not over 12 feet long should be 2 X 6 inches, from 12 feet to 18 feet 2 X 7 inches and 2 X S inches, and over that length 2 X 10 inches. On the whole it will be cheaper to reduce the length to 10 or 12 feet by means of purlins. An exam ination of the framing plans shows that our rafters are about fifteen feet long and two by seven inches in size, set twenty inches on centers. The roof is a hip roof, that is, a roof which draws in from all sides, which is the strongest kind of roof, so that we shall not have to pro vide any special sup ports, and shall only have to see that the proper pitch is given according to plans, that the valleys are properly put in and are extended to the ridge or to the hips, and that the openings are of the right size and in the • right positions. All portions of the roof must be well spiked together, the ridges per fectly straight and level and in the center, and the rafters all set exactly to a line.
Partitions. With the covering in of the building we may turn to the completion of the inside partitions, and these must be carefully followed to sec that the studs are straight and plumb. Crooked studding may be straightened by cutting with a saw on the concave side and then wedging the eut apart. All studs which bear an extra weight, as at the sides of large openings, should be examined to see that they have a sufficient support on the partition under and do not come between the studs, in which case a block should be cut in under the partition cap, and the same should be clone where heavy timbers bear between studs. All corners must be examined to see that they are made solid for lathing (Fig. 2S), and that provision is made for running pipes, etc. If any of the unsupported partitions running parallel with the joists are found to have a considerable span. so that there is danger of too much sagging, the difficulty may be overcome by trussing the partition at a small cost and if by any means such a partition is used to support floors or other partitions over, this should be clone in any case. The studs at the sides of all openings are to be doubled, and all openings of more than three feet are to be trussed. The head of all openings should be double, with the lower piece an inch from the upper so that if there is any sagging of the upper or weight-bearing piece it will not affect the lower one to which the finish is nailed. All the partitions should be bridged, and all sliding door pockets sheathed with end joints secured, so that there will be no possibility of a board starting off. The lining of sliding door pockets should be set upon heavy sheathing paper in such a way as to prevent air drafts from the cellar which are a source of great annoyance.