Window Installation: What a Good Install Looks Like
Full-frame vs. insert installs, flashing details, and the shortcuts that cause leaks.
The difference between a quality window install and a shortcut install isn't visible on day one — it shows up as drafts, leaks, and rot 5-10 years later. Knowing what to look for during install prevents the bad outcomes that cause windows to fail prematurely.
Insert vs. full-frame
Insert (pocket) install: new window fits inside existing frame. Faster, cheaper, less disruption. Only appropriate if existing frame is structurally sound and dry.
Full-frame install: existing window and frame are completely removed down to the rough opening. New flashing, sealing, and trim. The right choice when frames are rotted, when adding window flashing where none existed, or when changing window size.
Critical details
Sill pan flashing under every window — channels any water that gets past the window seal to the exterior. Often skipped on cheap installs.
Backer rod and quality sealant (not just caulk) around the perimeter. Spray foam insulation in the gap between window frame and rough opening (low-expansion only — high-expansion warps frames).
Quality interior trim that lets you see how the install was done. Shortcut installers often hide poor work behind quickly-applied trim.