The short answer
Check the Flashing First
Flashing is the metal strip that seals the gap between your chimney and roof. Over time, it can rust, pull away, or develop holes, letting rainwater run down into your home. Look for visible gaps or lifted edges, especially after a storm, and consider re-sealing or replacing worn sections.
If the flashing looks fine, the problem may be the step flashing that overlaps shingles. Water can wick behind it if the sealant has dried out. A simple caulk bead along the top edge can stop minor leaks, but larger damage needs professional attention to prevent rot and interior stains.
- Inspect flashing for rust or gaps
- Check sealant around flashing edges
- Look for lifted or bent metal pieces
- Watch for water stains on ceiling near chimney
Inspect the Chimney Crown
The crown is the concrete or stone cap at the top of the chimney. Cracks in the crown allow rain to soak into the brick and mortar below. Even hairline cracks can widen over time, especially with freeze-thaw cycles in winter, so repair them early to avoid bigger leaks.
A missing or damaged crown leaves the chimney top exposed. Water then runs down the inside of the flue or through the masonry, appearing as damp spots on interior walls. Rebuilding or sealing the crown is often the fix, but a professional can tell you if replacement is needed.
Look at Mortar and Brick
Mortar joints between bricks can crumble or develop gaps, letting water penetrate. This is common on older chimneys, especially after years of weather exposure. Use a screwdriver to gently probe the mortar; if it flakes away easily, it needs repointing, which means removing old mortar and replacing it with fresh material.
Bricks themselves can also crack or spall, where the surface flakes off. Water then enters through these weak points. If you see white staining, called efflorescence, it indicates moisture moving through the masonry. Addressing these issues promptly prevents structural damage and keeps water out of your living space.
- Probe mortar with a screwdriver
- Look for cracked or spalled bricks
- Notice white efflorescence stains
- Check for damp interior walls near chimney
Consider the Chimney Cap
A chimney cap sits on top of the flue and keeps rain, debris, and animals out. If the cap is missing or damaged, water can pour directly down the flue and into your fireplace or surrounding walls. Check that the cap is securely attached and has no holes or rust.
A cap with a screen also helps with ventilation, but it needs to be clear of soot and leaves. If water is coming in, a new cap might be all you need. This is a simple fix that many homeowners can do, but if the flue is damaged, call a professional.
When to Call the Pros
If you cannot find the source of the leak, or if water damage has already stained walls, ceilings, or insulation, it is time to bring in local water damage pros. They can inspect the area thoroughly, find hidden entry points, and dry out any damp materials to prevent mold growth.
Water that has soaked into drywall or wood can weaken structures over time. The pros use moisture meters and drying equipment to handle the job correctly. If you live in Fresno, act quickly after a leak to limit damage and keep repair costs down. Policies vary, and your insurer decides what is covered.
- Hidden leaks behind walls or ceilings
- Visible water stains or peeling paint
- Musty odor suggesting mold growth
- Sagging drywall or soft wood
Talk to someone now
Call (559) 272-9793 any time, day or night, and describe what happened.
Call Now (559) 272-9793Frequently asked questions
Can I fix a chimney leak myself?
Small fixes, like re-caulking flashing or replacing a cap, are doable. But if you suspect structural issues or have interior water damage, call a professional. They can safely inspect the roof and chimney and address the root cause.
How do I know if my chimney flashing is bad?
Look for rust, gaps, or lifted edges on the metal flashing. Also check for water stains on the ceiling or walls near the chimney. If you see daylight through any gap, that is a clear sign of a problem.
What should I do if water is already inside?
Dry the area quickly with towels or a fan, and move furniture away. Then contact local water damage pros to assess and dry the affected spaces. They can also help document the damage for your insurance claim.
More questions and answers
- Why Is There Water Around the Base of My Toilet?
- Why Is Water Coming in Through My Brick Walls?
- Why Is Water Coming Through My Basement Floor Cracks?
- Why Do Water Stains Keep Coming Back on My Ceiling?
- How Do I Temporarily Stop Water Coming Through a Crack?
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