Leaky Chimney? Here’s What’s Really Going On

If you’ve noticed water stains near your fireplace, a musty smell, or visible moisture inside your chimney, you’re not alone. Chimney leaks are one of the most common (and frustrating) problems Wisconsin homeowners face—especially with our freeze-thaw cycles and heavy spring rains. At Bollerud & Sons Masonry in Milton, we’ve seen it all. Here’s what might be happening—and how we can help fix it.

Common Causes of Chimney Leaks

1. Damaged or Missing Flashing
Flashing is the metal barrier that seals the gap between your chimney and the roof. Over time, it can crack, rust, or pull away—allowing water to seep into your attic or down your walls. Improper installation is also a common issue we see. We repair and seal flashing with high-performance materials to prevent future leaks.

2. Cracked Chimney Crown
The crown is the concrete or mortar top of your chimney. Its job is to keep rainwater out and shed it away from the flue. Cracks in the crown—often caused by age or temperature swings—let water penetrate the structure. We can repair or rebuild damaged crowns with waterproof sealant or new concrete to restore your chimney’s defenses.

3. Missing or Broken Chimney Cap
A chimney cap acts like an umbrella for your flue. Without it, rain pours directly into your chimney system. Water can rust dampers, deteriorate liners, and lead to mold or odor problems. We install durable, stainless-steel chimney caps to keep water, animals, and debris out.

4. Porous or Spalling Brickwork
Bricks and mortar can absorb water like a sponge. When that trapped moisture freezes, it expands and causes bricks to crack or crumble—known as spalling. Left untreated, this damage only worsens. Our team repoints and waterproofs masonry to restore strength and prevent future leaks.

Why Prompt Repair Matters

Moisture is a chimney’s worst enemy. Even small leaks can lead to thousands in damage—from moldy insulation to ruined drywall and deteriorating chimney liners. Early detection and expert repair save money and extend the life of your chimney.

Trust the Local Masonry Experts

Bollerud & Sons Masonry has been protecting chimneys across Rock County for generations. We know Wisconsin weather, and we know what it takes to keep your masonry sealed tight. Whether it’s a quick fix or a full chimney rebuild, we deliver honest, reliable work every time.

Don’t wait until water damage gets worse.
Call us today for a chimney inspection and get peace of mind before the next storm hits.