Post-Storm Homeowner Guide

After the Storm: A Window, Door & Flashing Leak Checklist for GTA Homes

What Toronto-area homeowners should check after heavy rain—and what to document before making repairs.

Heavy rain can expose water issues around windows and doors that may not be immediately obvious. After a major storm, taking a few minutes to inspect your home can help you identify areas that deserve a closer look.

For GTA homeowners: complete your post-storm inspection within 24–72 hours while the evidence is still fresh, and do the exterior portion when conditions are dry.

On This Page

Start With a Quick Interior Scan

Begin inside your home. Walk around the windows, exterior doors, patio doors, and nearby window wells.

Check for water.
  • Standing water near doors, windows, or window wells
  • Water collecting near thresholds or lower corners
Use the smell test.
  • Musty or damp smells around window and door trim
Look at finishes.
  • Swollen baseboards
  • Bubbling paint
  • Discoloration under windows
Use the touch test.
  • Bottom corners of window sills or door thresholds that feel cool or damp

Check Your Windows for Signs of Water Intrusion

Next, take a closer look at your windows. Do not focus only on the glass—the frame, sill, drywall, and drainage openings can also provide important clues after heavy rain.

Above the frame
  • Water stains or dark lines on drywall
Between the panes
  • Condensation or fog between glass panes
Along the sill
  • Peeling caulking or paint
  • Soft or spongy drywall around the frame
Outside the window
  • Weep holes clogged with mud or storm debris

Don't Forget Your Exterior Doors & Patio Doors

Windows are not the only openings that should be checked after a storm. Pay attention to exterior doors and patio doors too.

  • Daylight visible around a closed exterior door
  • A threshold that is loose, cracked, or pulling away
  • Water pooling at patio door corners after the rain has stopped
  • A door that has become difficult to lock or latch
Why operation matters: if a door suddenly becomes difficult to lock or latch after saturated conditions, the frame may have shifted. That change is worth documenting.

The Flashing Check: This Is Critical

After a major storm, the window itself is not always the source of the leak. Failed water management around the opening can allow water to move behind exterior finishes.

Above the Window

  • Dark streaks running down from the top trim
  • No metal head flashing visible

These signs can mean water is getting behind siding or brick.

Brick or Stucco Homes

Look for efflorescence—white powdery marks below windows—which can indicate water getting behind the veneer.

Siding Homes

Check for warped or buckled J-trim around the windows.

Under the Sill

Staining on the exterior wall directly below the window sill can point to pan flashing failure.

“Caulking is not flashing. Flashing is your last line of defence that directs water out, even when caulking fails.”

If you see thick beads of caulking where metal flashing should be, do not assume that adding more caulk is the right fix. The checklist identifies that as a temporary approach that can fail during flooding.

Take a 15-Minute Walk Around Your Home

Once conditions outside are dry, walk around your home and inspect the areas surrounding your windows and doors.

Window Wells

Look for leaves, mud, or standing water. Clear debris and check the drain.

Grading

Check whether the ground slopes toward the home. It should slope away approximately 6 inches over the first 3 feet.

Downspouts

Make sure downspouts are not dumping water directly beside doors or window wells.

Drip Caps

Check above doors and windows for drip caps that are damaged or missing.

See Something Wrong? Document It Before You Repair It

If you discover a possible leak or signs of storm-related water intrusion, document the condition before removing trim or applying fresh caulking.

Before cleanup or repairs:

  • Take timestamped photos or video of the interior stain and the exterior of the same window.
  • Do not rip out trim or re-caulk yet—document first.
  • Note the date and time the rain started and stopped.
  • Record which side of the home was facing the wind.
  • If drywall is soft, save a sample to help distinguish the source of the moisture.

How Many Warning Signs Did You Find?

One unusual sign may not tell you the full story. The goal is to understand where the water is coming from and how it is being managed before covering up visible symptoms.

Checked two or more boxes? Consider a flashing inspection before re-caulking. This can help avoid trapping water and may help protect your warranty documentation.

Heavy Rain Is a Good Time to Pay Attention

Storms put your home's exterior through conditions that are not present on an ordinary day. Once the weather clears, take a few minutes to look around.

Include these areas in your post-storm check:

  • Window sills and frames
  • Exterior doors
  • Patio doors
  • Flashing
  • Window wells
  • Downspouts
  • Exterior grading
  • Drip caps

Not Sure What You're Seeing?

If you noticed multiple warning signs around your windows or doors after heavy rain, Optima Windows & Doors can help you take a closer look before you re-caulk or cover up the evidence.

Contact Optima Windows & Doors