Think Twice Before Installing Retrofit Windows

If your home has wood siding and exterior wood trim, retrofit windows may seem like a quick and convenient replacement option. However, this installation method can create moisture problems that eventually lead to leaks and dry rot. Here’s some more information:

The risks
A retrofit window is installed inside the existing window frame after the glass, sliding panels and center divider are removed. Since the original frame remains in place, the new window will be smaller, which means your contractor will likely use self-adhesive vinyl trim to cover the surrounding gaps. On a wood-sided home, this method can trap moisture behind the exterior trim and cause the wood to rot over time.

The better option
For stronger moisture protection, remove the existing window and install a traditional nail-on window. This involves removing the exterior trim and cutting back the siding so the new window’s nailing fin can be properly attached, flashed, and caulked directly to the framing. Although a nail-on installation requires more work, it creates a more reliable waterproof barrier and helps protect the surrounding wood from long-term damage.