How to inspect windows and glazing

Step by step

1. 1

   Check the rough opening and sill pan

   Confirm the rough opening is the right size, square, plumb, and level, and that a sill pan flashing with end dams and a back dam is installed before the unit. Water that gets past the frame has to land on a pan that drains out, not into the wall.

2. 2

   Verify the unit and its condition

   Confirm the window or storefront is the specified product, size, and performance rating per the submittal, and check for shipping damage, seal failure, or scratched glass before it's set.

3. 3

   Inspect anchoring and shimming

   Check that the unit is anchored per the manufacturer's pattern, shimmed at the right points so it isn't racked, and that fasteners don't compromise the frame. An over-shimmed or racked unit won't seal or operate.

4. 4

   Confirm integration with the WRB and flashing

   Verify the flashing sequence around the unit: jamb flashing lapping the sill pan, head flashing over the jambs, and the WRB lapping over the head. The unit has to be woven into the barrier, not just sealed to the face.

5. 5

   Check the perimeter seal and backer rod

   Inspect the perimeter sealant joint for correct joint width, backer rod, tooling, and a two-sided bond — and confirm interior and exterior seals match the detail. Confirm any required weeps in the frame are open.

6. 6

   Verify glazing, setting blocks, and gaskets

   For glazing, confirm glass type and thickness, setting-block placement, edge bite, and that gaskets or wet seals are continuous. On curtain wall, check pressure plates, gaskets, and that the system drains through its own weep path.

7. 7

   Confirm operation and hardware

   Operate every operable unit — sash, lock, weatherstrip — and confirm smooth operation and full engagement. A window that binds or won't lock is both a security and an air-leakage defect.

8. 8

   Test, document, and close

   Where water testing is specified, confirm representative units are tested and pass, photograph the pan and flashing integration before the interior is closed, and punch or write up any leak, racked unit, or failed seal.

Questions people ask

Why does a window need a sill pan if it's sealed all around?

Because sealant fails and water finds a way in. The sill pan is the backup: it catches water that gets past the frame and drains it back out to the exterior instead of into the wall. Belt and suspenders.

How does inspecting a curtain wall differ from a punched window?

A curtain wall is a drained-and-vented system — you're checking that it manages water internally through its weep path, along with pressure plates, gaskets, and anchorage. A punched window relies on the surrounding wall's barriers, so integration with the WRB and flashing is the focus.