Vinyl Windows

Most of the vinyl replacement windows Lehigh Valley homes received over the past thirty years went into the same kinds of houses: the brick ranches of Whitehall and Palmer, the twins and rowhomes of Allentown and Bethlehem, and the coal-era doubles of Scranton and Wilkes-Barre, many of them rentals. Vinyl became the default because it does the basic job without fuss. It never needs paint, the sashes are light enough for anyone to lift, and it is stocked in every common style. If you are replacing vinyl that went in during the 1990s, you are seeing what the material does over time, and that experience should inform what you buy next.

Vinyl is PVC, and PVC moves with temperature. A dark frame on a south-facing wall in July is far warmer than the same frame at dawn in January, and the material grows and shrinks between those extremes. Over years of freeze-thaw that motion works at the corner welds and at the seal between glass and sash, which is why fogged glass and a sash that sticks in summer and rattles in winter are the classic ways an older vinyl window announces its age. The frames also stiffen with cold and soften with heat, so a very wide or very tall vinyl sash can bow slightly on a hot afternoon.

None of that makes vinyl the wrong answer everywhere. For a house you expect to sell within a decade, a rental you want to keep simple, or a standard-size opening in a sheltered wall, a well-made vinyl window is a reasonable choice. Our editorial stance for a home you plan to stay in is composite first, because it holds its shape through the same weather for far longer. What follows is how to tell a vinyl window worth installing from one that will be back on the replacement list.

The glass is where vinyl lines differ most. Every line offers two panes with a Low-E coating and a gas fill, but the spacer between the panes is what determines whether the seal survives twenty winters. A warm-edge spacer made of a stable material outlasts a plain metal one and keeps frost off the glass edge in January. Ask which spacer is in the quote, and ask to see the corner of a sample sash; a clean, fully fused weld with no gap is the sign of a frame that was made carefully.

Frame construction matters as much as glass. A multi-chambered frame with internal walls is stiffer and warmer than a hollow one, and some lines add reinforcement in the meeting rail so the lock keeps pulling the sashes together as the material ages. Hardware should be metal, not plastic, at the cam locks and tilt latches, since those are the parts that fail first. Screens on vinyl double-hungs are usually half screens; confirm the frame holds them snugly, because a loose screen rattling in the wind is a common complaint.

Vinyl is light, which makes it the easiest material for an insert installation into a sound wood frame. Your matched installer will probe the sill and jambs for rot first; vinyl is also the material most often set into frames that should have come out, and the new window then inherits every draft the old frame had. If the sill is soft or the frame is out of square, a full-frame vinyl unit set to the rough opening is the right call, and the difference in the finished wall is small.

Because vinyl moves with temperature, the gap between the new frame and the opening must be filled correctly. Low-expansion foam that will not bow the frame, a backer rod and sealant at the exterior, and enough shims to hold the frame square while the foam cures are what separate a window that operates smoothly in August from one that binds. A crew of two typically works room by room, and a whole floor of standard double-hungs is often finished in a day. On homes built before 1978, lead-safe work practices apply to the removal of the old sashes.