Leaks & Building

BuildingWrench repair guide

Leaks & Building

Commercial Window Leaks During Rain? How to Find the Entry Point

A leaking commercial window may admit water through perimeter sealant, head flashing, masonry joints, glazing gaskets, sill joints, or wall cavities above the window. Start high and work down.

Last reviewed 2026-09-12 · General facility-maintenance information, not a substitute for site procedures, manufacturer instructions, codes, or qualified professional judgment.

Routine facility fixSkill: Beginner-friendlyFormat: Diagnose → Fix → Test
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Quick answer

Do not assume the visible wet spot is the failed joint. Water can enter above or beside a commercial window through perimeter sealant, flashing, masonry, glazing gaskets, or the wall assembly and then travel before appearing indoors.

Safety boundary

Protect occupants first and avoid unsafe roof, ladder, ceiling, electrical, or structural access while tracing water.

Full troubleshooting steps are in Pro

The safety boundary, quick answer and stop-work conditions above stay free. Pro opens the likely causes, symptom table, step-by-step procedure and preventive maintenance for this guide.

Stop and call a licensed professional when

  • Leak originates inside wall cavity
  • Glazing system needs specialist repair
  • Access requires lift or fall protection

Mistakes, FAQ, parts and tools

Pro opens the rest of this guide: common mistakes, field FAQ, the parts list, and the tools for the job.

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Leaks & Building

Water Coming Under an Exterior Door: How to Find the Entry Path

Water at an exterior door can come through the threshold, failed sealant, door sweep, jambs, masonry joints, or exterior drainage that sends water toward the opening. Start outside and follow the path instead of immediately replacing weatherstripping.

Leaks & Building

Ceiling Leak After Rain? How to Trace Where the Water Is Coming From

A wet ceiling tile often is not directly below the exterior leak. Rainwater can travel along roof decking, framing, conduit, piping, insulation, or wall cavities, so document the wettest point and trace the path upward and outward.

Leaks & Building

Water Leak: Find the Source and Control the Damage

Stop the water if there is an accessible isolation valve, keep people and electricity away from it, then trace the path from the lowest wet point up to the highest. Condensate, roof, supply piping, and drain leaks all look the same on a ceiling tile.

Leaks & Building

Commercial Gutter Overflowing: Find the Blockage or Capacity Problem

Overflowing gutters usually come from debris, blocked downspouts, poor slope, undersized drainage, or roof water overshooting the gutter. Watch where the water actually goes.