Trade walkthroughs
How to inspect a curtain wall
A curtain wall doesn't try to keep every drop of water out; it manages water inside itself and drains it back out through a weep path. That means the inspection is about the system working as designed: anchored to carry its load and movement, sealed and gasketed at the right lines, and draining where it's supposed to. Once the interior is closed and the wall is glazed, the anchorage and the internal drainage are out of reach.
For the superintendent or envelope lead verifying stick or unitized curtain-wall installation against the shop drawings, anchor details, and the tested mock-up.
Step by step
Start from the approved mock-up
Where a performance mock-up was built and tested for air, water, and structural movement, use it as the accepted benchmark. Every field condition — gasket lines, sealant joints, anchor detail — should match what the mock-up proved to pass.
Verify anchors, embeds, and dead-load supports
Confirm anchor type, location, and slotting match the shop drawings, that embeds and slab-edge conditions were verified before framing, and that dead-load anchors and wind anchors are where the details show them. Anchors carry the wall and let it move — the wrong one in the wrong place is structural.
Check framing plumb, alignment, and movement joints
Verify mullions and transoms are plumb, aligned, and set within tolerance, with the specified expansion and stack joints left open to move. A wall shimmed tight or racked at the anchors can't take thermal and building movement without stressing the glass and seals.
Inspect gaskets, pressure plates, and thermal breaks
Confirm gaskets are continuous, correctly seated, and lapped or vulcanized at corners, that pressure plates are fastened at the specified spacing and torque, and that the thermal break is intact. A skipped fastener or a pinched gasket is where the pressure-equalized system loses its seal.
Verify glazing, setting blocks, and edge bite
Check glass type, coating orientation, setting-block placement, edge bite, and that captured or structural-silicone glazing matches the detail. For structural silicone, confirm the joint was cleaned, primed, and cured per the manufacturer before it's loaded.
Confirm the weep path is open and continuous
Trace the internal drainage: weep holes and baffles open and clear, flashing and end dams at the sill and stack joints, and gutters draining out rather than into the building. A blocked weep path turns a drained wall into a reservoir.
Verify perimeter seals and transitions to the barrier
Check the perimeter joint between the curtain wall and adjacent construction — backer rod, sealant, and transition membrane tying the wall into the building's air and water barrier. The frame can be perfect and still leak at a poorly detailed perimeter.
Test, document, and punch
Where field water testing is specified, confirm representative bays are tested and pass, photograph anchors, weeps, and perimeter transitions before the interior closes them in, and write up any leak, racked frame, or failed seal as a punch or nonconformance item.
What gets missed
- Treating a curtain wall like a barrier wall and caulking the weeps shut instead of letting it drain.
- Anchors installed without the slots or the movement the shop drawings call for, so the wall can't move.
- Structural-silicone joints loaded before the substrate was cleaned, primed, and fully cured.
- A perimeter joint sealed to the face instead of tied into the building's air and water barrier.
- Closing the interior before anchors, weeps, and perimeter transitions are photographed and cleared.
Questions people ask
- How is a curtain wall different from a window wall or storefront?
- A true curtain wall hangs off the structure and spans floor to floor, carrying only its own weight and wind. Window wall and storefront sit between or on the slabs. The anchorage and movement details differ, so inspect against the specific system's shop drawings rather than a generic checklist item.
- Does my walk replace the specialty subcontractor's water test?
- No. The glazing subcontractor and, where required, a third-party envelope consultant run the specified air and water performance tests. Your walk verifies installation against the shop drawings and the mock-up and tracks the punch. Keep both records in the file.
Terms worth knowing
Checklists that make this a one-tap job
Free, field-ready checklists, each with the photo every item needs before it can be submitted.
Related guides
- How to inspect windows and glazingInspect windows and glazing from rough opening to seal — pan flashing, anchoring, integration with the WRB, and glazing — where water and air most often get in.
- How to inspect the building envelopeInspect the envelope as a system — air barrier, water-resistive barrier, flashing, transitions, and sealants — with the continuity and mock-up that make it perform.
- How to inspect metal panel claddingInspect metal panel cladding as a rainscreen — WRB and flashing, sub-girts and clips, panel attachment and engagement, joints, and terminations — before it's closed in.
Reading the steps is one thing. Proving you walked them is the job.
RTI holds the submit button until every mandatory item is answered and the photos are attached, then chains the record so it can be proven untouched later.