The double-hung window is maybe the most familiar window type. It is composed of a lower and upper sash that slide vertically in separate grooves in the side jambs or in full-width metal weather-stripping ( see drawing ).This kind of window offers a maximum face opening for ventilation of 1/2 the total window area. Each sash is supplied with springs, balances, or compression weather-stripping to hold it in place in any location. Compression weather-stripping, for instance, stops air infiltration, provides strain, and acts as a counterbalance ; a few types permit the sash to be removed for straightforward painting or repair . The jambs are made from nominal 1-inch lumber ; the width makes provisions for use with drywall or plastered interior finish. Sills are made of nominal 2-inch lumber and sloped at about three in twelve for good drainage ( figure D ). Sash are usually one three / eight inches in thickness and wood combo tempest and screen windows are customarily eleven / eight inches deep. Sash could be split into a considerable number of lights by small wood members called mentions. A ranch-type house may supply the best appearance with top and bottom sash split into 2 horizontal lights. A colonial or Cape Code house generally has each sash split into 6 or 8 lights. Some makers provided preassembled dividers which snap in place over a single light, dividing it into 6 or 8 lights. This simplifies painting and other upkeep. Assembled frames are placed in the coarse opening over strips of building paper put round the fringe to reduce air infiltration. The frame is nailed and plumbed to side studs and header thru the casings or the blind stops at the sides.
Where nails are exposed , for example on the surrounding, use the corrosion-resistant type. Hardware for double-hung windows comprises the sash lifts that are attached to the bottom rail, though they're infrequently eliminated by providing a finger groove in the rail. Other hardware is composed of sash locks or fasteners found at the meeting rail. They not only lock the window, but draw the sash together to supply a "wind tight" fit.Double-hung windows can be prepared in a considerable number of methods -- a single unit, doubled ( or mullion ) type, or in groups of 3 or even more. 1 or 2 double-hung windows on every side of an enormous still insulated window are sometimes used to effect a window wall. Such massive openings must be framed with headers huge enough to carry roof loads.