The short answer
Find the Leak Source
Water entering through a bay window usually comes from one of three places: the window frame itself, the flashing where the window meets the roof or wall, or the roof above. Check the interior first. Look for water stains on the ceiling, walls, or windowsill. Feel the frame and the joint where the window meets the wall for dampness.
Then, inspect the exterior if you can do so safely. Look at the flashing, the metal or rubber strip that seals the top and sides of the window. Cracks, gaps, or lifted edges are common culprits. Also examine the sealant around the glass panes. Heavy rain and high humidity can speed up sealant wear.
Stop Active Dripping
Your immediate goal is to stop water from spreading. Use towels, a bucket, or a large pan to catch the water. If the leak is steady, you can also cut a small hole in the drywall below the leak to let water drain into a container, which prevents it from running along the wall. Do this only if you are comfortable with minor damage.
To seal a small crack or gap temporarily, dry the area with a cloth and apply a bead of silicone caulk. Press it in with a wet finger to fill the gap. This works for minor leaks but is not a permanent fix. For larger openings, you might need to use a piece of plastic sheeting taped over the area until a proper repair can happen.
- Move furniture and rugs away from the window.
- Use a bucket or large pan to catch dripping water.
- Dry the leak area with a towel before applying caulk.
- Apply silicone caulk to small gaps and cracks.
- For larger gaps, tape plastic sheeting over the opening.
- Keep a mop and rags handy for cleanup.
Check Roof and Flashing
Bay windows often have a small roof over them, especially in homes with a protruding bay. That roof is a common leak point. Inspect the shingles or metal roof for missing, cracked, or lifted pieces. Check the flashing where the roof meets the wall. If the flashing is loose, water can run behind it and into the window frame.
You can also check the gutters above the bay window. Clogged gutters can cause water to overflow and pool against the window. If you see standing water on the bay window roof after a storm, that is a sign of poor drainage. You can clear debris yourself, but for repairs to flashing or roofing, consider calling a roofer.
Inspect Window Sealant
The sealant around the glass panes and the frame deteriorates over time. Sun and rain cause it to crack, shrink, or pull away. Run your finger along the sealant beads. If they feel brittle or you see gaps, that is an entry point for water. Reapplying caulk around the glass and frame can stop many leaks.
Remove old, loose sealant with a putty knife or a scraper. Clean the surface with a mild detergent and let it dry completely. Then apply a fresh bead of exterior-grade silicone or butyl rubber sealant. Smooth it with a wet finger. This task is doable for a careful homeowner, but if the leak is extensive, a professional may be needed.
When to Call the Pros
If you cannot locate the leak or if water keeps coming after your temporary fixes, it is time to call local water damage pros. They can trace the water path and identify hidden issues, such as rot in the window frame or damage to the wall structure. They also have tools to dry out the area and prevent mold growth.
Water damage can lead to mold, which is a health concern. If you see mold or smell a musty odor, that is a sign of ongoing moisture. The pros can assess the extent of damage and perform cleanup. They can also coordinate with a roofer or window installer if the repair is beyond their scope. Act quickly to limit damage.
- You cannot find the source after a thorough check.
- The leak returns after you apply sealant.
- You see water stains spreading on the ceiling.
- You notice mold or a musty smell.
- The window frame feels soft or rotted.
- The leak is near electrical outlets or fixtures.
Water damage does not wait
Call (386) 272-5697 any time, day or night, and describe what happened.
Call Now (386) 272-5697Frequently asked questions
Can I fix a bay window leak myself?
Yes, you can handle minor sealant cracks and simple flashing gaps with caulk and a ladder. But if the leak is from the roof or involves structural damage, you should call a professional. A temporary fix is fine, but a lasting solution often requires expertise.
How long does a temporary seal last?
A silicone caulk seal can hold for a few weeks to a few months, depending on the weather and the size of the gap. It is not a permanent repair. You should still plan for a proper fix, such as replacing flashing or resealing the entire window, to avoid repeated leaks.
What causes a bay window to leak?
Common causes are worn sealant around the glass, damaged flashing where the window meets the roof, clogged gutters, or a roof leak above the window. In humid climates, sealant degrades faster. A thorough inspection of these areas will usually reveal the source.