Double Hung Replacement Windows

Double hung windows have two separate parts of the window, an upper sash and a lower sash. In some models both sashes can be opened and in other styles one of the sashes remains stationary while only the other one (usually the bottom) can be opened and closed.

The framework of a double hung window consists of styles and rails along the side jambs, which help the window to slide up and down, as well horizontal sashes along the frame that hold the window in place. There are typically two separate panes of glass, one on the top and one on the bottom, that are framed within their own sash and operate independently of one another. Some window manufacturers offer preassembled dividers that separate the glass into smaller subsections, and other manufacturers also offer the option of having the dividers set within the glass, which makes for easier cleaning and maintenance. The sections of glass on the window are sometimes referred to as lights, so if you see a window that says it has ’six lights’, it means that there are dividers on the sash that separate the expanse of glass into six sections.

Along the side rails and stiles, double hung windows include balance springs that work to hold the moveable sash in a particular spot when opened. This keeps windows from dropping down when opened and allows homeowners to open the windows as much or as little as they’d like. The sides of the sash also include compression weather stripping, which is used to seal off drafts, but it also acts as a counterweight.

Most double hung windows come standard with one inch wide jambs, so they can easily fit into a wall and accommodate the thickness of the drywall or plaster. The bottom sills are typically two inches wide and are slightly sloped (usually about 20 degrees) to allow for good drainage. The windows may also include hardware, such as sash lifts or handles, so that the windows can be easily opened and closed. In some cases, the sash contains a finger groove instead that can be used to move the sash up and down easily.

Some models of double hung windows allow for the removal of the entire window sash for easier cleaning and maintenance. Other styles allow the sash to be popped out on an angle but not completely removed, and this is also done to ease cleaning and maintenance of the window.Hardware locks or fasteners for the windows are usually installed along a section of the window called the meeting rail, which is where the top and bottom sashes meet and overlap. The locks and fasteners lock the window in place so it can’t be opened and provide a tight seal between the two sashes where they meet.

Installation of double hung replacement windows is usually a fairly simple process. Once the old window is removed, the opening is lined with strips of building paper, which helps with insulation and minimizing drafts. The fully assembled window frames are then placed in the rough opening. The window frame is leveled and then nailed into place. Windows are nailed to the side studs and header through the casings or blind stops. If nails will be exposed to the elements, then corrosion resistant nails are a must.

Once the windows are attached to the frame of the house, then the panes of glass can be inserted if they are removable and were not kept in place during installation. The frame section that is located between the jamb and the casing allows room for a storm sash or screen. Once the window is fully assembled, the any interior or exterior molding or trim can be installed.