42. Combination Frame

The better class of wooden buildings are now framed on a sort of combination of the balloon and old-fashioned methods. The braced frame is adopted as far as the sills, posts, girts and braces are concerned, but the common studding is generally mortised at the lower end only and spiked at the upper end, and generally the plate is made of two thicknesses of 1x4 or 3x6 plank spiked to the top of the studding and breaking joint.

Fig. 18.

An example of this method of framing is shown in Figs. 19 and 20, which are taken from the framing drawings of a building built in the suburbs of Boston.

Fig. 19.

Within the limits of that city (outside of the fire limits) this method of framing is required by law, the building ordinance reading:

All wooden buildings erected outside said (lire) limits shall be built with posts, girts and plates properly mortised, tenoned, braced and pinned in each story and supported by suitable studding, the studs to be not more than 32 inches apart, the posts and girts to be not less than 4x8 inches or equivalent thereto.

In the opinion of the author this method of framing should be employed for all large buildings and for the better class of dwellings.

43. Dimensions And Details. - Sills

Where the sill rests on a brick or stone wall, and the cellar openings are narrow, a 6x6 sill answers very well, but if the sill rests on posts, or there are wide openings beneath, the sills must have sufficient strength to support the wails and floors above the opening. It should also be remembered that in this method of framing a good deal of the sill is cut away by mortising, as shown in Fig. 21, thereby greatly lessening its strength. In all large or heavy buildings the sill should be at least 6x8 inches and laid with the board side on the wall.

Fig. 20.

The sills should always be imbedded in cement mortar and should set in at least 1 inch from the outside face of the wall. They should be halved and pinned at the angles * and wherever splices occur, but when practicable they should be in one length from angle to angle; they must, of course, extend all around the house. In commencing the frame of a wooden building the sills are the first timbers to be cut and put in place.

If the basement is 5 feet or more above grade, the sill should also be bolted to the masonry by -7/8-inch bolts 30 inches long, solidly bedded in the wall and extending through the sill, with the nut turned up tight. The sills of buildings having the first story of brick or stone should also be secured in this way.

Studding. - For frame buildings of medium size 2X4-inch studding is almost invariably used; for churches, schools, etc., 2x5 or 2x6 studding should be used. In the cheaper class of buildings the studding is generally set 16 inches on centres, but a much better building is obtained if the spacing is made 12 inches. All studding for buildings that are to be plastered should be sized, by passing through a planer, to a uniform width. The lower end of the studding should be mortised into the sill, either as shown at a or at b, Fig. 21; the latter method is the better of the two and should always be used for 5-inch or 6-inch studding.