Composite Windows

The composite windows Lehigh Valley homeowners ask about most are going into houses people intend to keep: brick-front colonials in Saucon Valley, Center Valley two-stories from the late nineties, and Lower Macungie split-levels where the kids have moved out and the owners have no plans to follow. A composite frame is built from a blend of wood fiber and polymer, or a similar engineered mix, formed into a profile that behaves more like a dense board than a hollow extrusion. That gives it two qualities this region punishes other frames for lacking: it barely swells in a humid August, and it does not shrink back hard when a January cold snap follows a thaw.

Our editorial stance is simple. For a home you plan to stay in, composite is the material we point to first, because it pairs the warm look of wood with a surface that never asks for a paint schedule. That stance comes from what homeowners tell us years after the install: sashes still travel evenly, dark exterior colors still read the way they did on delivery day, and the interior finish still looks like trim rather than plastic. The local pro we connect you with may carry one composite line or several; either way, the conversation should center on how the frame handles moisture and movement.

Where composite earns its place is at the corners and in the glazing pocket. A frame that moves at a different pace than the glass it holds puts the perimeter seal under stress twice a day on a sun-facing wall, heating through the afternoon and cooling fast after dusk. Composite moves less than vinyl and stays closer to the glass, so that seal ages slowly. It also grips screws the way wood does, which matters for casement hinges and double-hung locks. Small details, but they decide whether a window still feels solid when it is fifteen winters old.

A composite frame is rigid enough to carry a heavier glass package without the sash sagging, so this is the material where a triple-pane conversation makes the most sense for bedrooms on the windward side of the house. Ask your matched installer to list the Low-E coating, gas fill, and spacer type for each opening; the south-facing living room and the north-facing bath do not want the same coating.

Hardware is where composite quietly outperforms. Because the frame takes a fastener the way wood does, hinges and locks stay tight instead of working loose over years of use. Look for cam locks you can work with a closed hand and tilt latches large enough to find without looking. Composite double-hungs weigh more than vinyl of the same size, so lift a sample sash: it should rise with even effort and stay wherever you leave it.

Most composite replacements in sound openings go in as inserts, which keep your interior casing and exterior trim intact. Your matched installer will check the existing frame for square, probe the sill for softness under old paint, and look at how any storm window has been draining. On the 1960s and 1970s ranches around Emmaus and Coopersburg the sill is usually fine; where water has gotten behind the frame, a full-frame install with new flashing is the honest answer.

Day-of, a crew of two typically finishes a composite house in one to two days depending on count and access. Because each unit weighs more than a vinyl equivalent, second-story windows are staged and lifted deliberately, and wide openings may arrive as mulled pairs the crew joins on site. Expect low-expansion foam in the perimeter gap, a cold-rated flexible sealant outside, and a walk-through where you operate every lock.