Why Toss Money Out a Double-Hung Window?

Old, worn-out, double-hung windows are the largest source of drafts and energy loss in many older houses. Replacing even a modest double-hung window may cost as much as $250, but it can be renovated for a fraction of the cost using a jamb liner kit, which typically costs about $50.

Years of opening and closing, the settling of the house and effects of the weather take their toll on a window. Wood sashes are durable, but the jambs they ride in wear out. The sash becomes loose in the jamb, and large gaps develop in the center meeting rail, allowing air to leak between the jamb and the sash and between the inner and outer sash.

Although the damage done to the window may have been years in the making, the renovation takes only a couple of hours per window.

Jamb liner kits made of vinyl or a combination of aluminum and stainless steel provide fully weatherstripped channels for old sashes to ride in. These replacement jambs, teamed with a high-quality exterior storm window, give the window a heat-loss efficiency equal to many double-glazed replacement windows.

The new replacement jambs have weatherstripped tracks that fit old window sashes snugly. Friction holds the windows open, eliminating the need for sash weights. This makes it possible for you to insulate the sash-weight compartments and stop another source of air infiltration.

The jamb liner must be at least as long as the existing window jamb is high. The manufacturer of your jamb liner may have specific instructions about measuring for the liner. For instance, one manufacturer asks that you measure the glass area of your window and then consult a chart to determine the correct size of the liner to purchase.

If you have a non-standard, site-built window with one or more different-size sashes, measure the distance inside the window channel between the bottom of the sash (not the windowsill) and the top of the sash. Purchase a jamb liner kit that is at least as long, or longer than, this measurement.

To install the new liners, first lubricate the edges of the jamb weatherstripping with the silicone lubricant provided in the kit. Next, place the windows in the jamb liners and check that the angled bottom of each liner faces down. Slide the windows together to the center of the jamb liner, then place the bottom of the liner into the old jamb.

Raise up the jamb liners and windows so the pointed end of the liners are as far forward as possible in the old jamb and rest against the outer stop. When the liners are fully upright, temporarily secure the top of the jamb liners with a nail or screw--but don’t drive the fastener home.

Slide the windows up and down, and check their fit in the jamb. They may be difficult to move at first, but the jambs will loosen after some use. If everything checks out, fasten the jamb liners to the old jambs with a nail or screw driven through the top of the jamb. The inside stop holds the jamb in place, so these fasteners are needed only until you install this stop.

Installing spring-loaded jamb liners allows the sashes to be removed for cleaning and repair. This job is only a little different from installing standard replacement jambs. These jamb liners are made from aluminum with a stainless-steel wear strip.

The spring-loaded channel is screwed or nailed to the left side of the existing jamb. A jamb liner is snapped into place on top of this, and a standard jamb liner is installed on the right jamb.

Next, to accommodate the increased thickness of the spring-loaded channel, cut off about three-fourths of an inch from the left side of the sash.

Push the sash against the left jamb liner to compress the springs, then push the window into the track on the opposite side of the jamb. Spring tension keeps the jamb in place.