Chimney Cap Replacement
A chimney cap, sometimes interchangeably referred to as a chimney crown, serves as a critical shield at the top of your chimney. Over time, exposure to harsh weather, cracking, or general material breakdown can weaken this structure. Replacing it restores vital protection against water intrusion and other damaging elements. Our service emphasizes a careful assessment of your chimney followed by the installation of a durable, properly formed replacement. We use proven, leading construction methods to ensure the new cap stands the test of time and lasts for decades.
Workmanship Guarantee
Monahan Masonry stands behind every project with confidence.
We confidently back the craftsmanship and longevity of our chimney cap replacements. Should any portion of our work ever fail, we’ll correct it at no cost to you. We’re dedicated to providing meticulous, reliable installations designed for lasting protection.
Key Benefits a Well-Constructed Chimney Cap
A well-constructed and correctly formed chimney cap acts as the first line of defense for your entire chimney structure. It directs water away, seals vulnerable areas, and prevents common issues that arise from exposure to rain, snow, and debris.
Here are the main reasons a proper chimney cap matters:
- It sheds rainwater and snowmelt away from the flue and structure, preventing water from seeping into cracks, eroding mortar, or damaging the interior liner and chimney structure.
- It incorporates expansion joints where the concrete cap meets the brickwork or flue tiles, allowing for natural expansion and contraction from temperature changes (such as heating during fires or seasonal shifts) without causing cracks in the cap.
- It helps protect against animal intrusion, falling debris, and blockages that could obstruct airflow or create hazards.
- It supports proper ventilation by allowing exhaust gases to escape while minimizing downdrafts that push smoke or odors back into the home.
- It extends the lifespan of the chimney by limiting water-related deterioration, which is one of the primary causes of costly repairs in most chimneys.
Even minor cracks or uneven surfaces in an existing cap can allow water to penetrate over time, leading to larger structural problems. A properly formed replacement addresses these vulnerabilities directly and helps prevent the need for more extensive chimney services, contributing to the long-term health and safety of your chimney.
Other Types of Chimney Caps
While the term chimney cap often applies to the protective top structure on traditional chimneys (sometimes called a crown), different styles exist to suit various chimney designs.
Prefab caps are commonly used for smaller utility or furnace chimneys, offering a more affordable and straightforward option compared to a custom-formed and poured concrete cap. Metal chase covers enclose the top of prefabricated or factory-built chimneys, protecting the entire chase area from weather and extending over the structure. Flue covers, also known as rain caps or flue-specific caps, seal individual flue openings to keep rain or critters from entering your home. The right type depends on your chimney’s build, whether it’s brick, metal, or prefab, ensuring targeted protection where it’s needed most.
Our Approach to Chimney Cap Replacement
We carefully evaluate every project to ensure brick replacement is the best solution for long-term durability. When it is, we follow a precise, step-by-step method to minimize disruption and achieve clean, integrated results.
1. Removing Defective Cap
We start by safely removing the existing deteriorated or cracked cap. We often use a specialty masonry saw equipped with a diamond blade to make precise relief cuts in the cap, allowing us to break it away more delicately during deconstruction. This careful approach helps avoid any damage to the surrounding brick, stone, or flue tiles, preserving the chimney’s original structure and preventing unnecessary additional work or expense.
2. Constructing Forms
We then set up custom forms around the chimney top to define the shape and boundaries of the new cap. These forms are precisely positioned to incorporate expansion joints around the flue tiles and at the brick interface, which prevent cracking by allowing for natural thermal movement. The design also includes a 2-inch overhang on all sides and a 1/4-inch drip edge integrated into the underside of the overhang to guide water away effectively and provide long-term protection for the masonry below.
3. Pouring Concrete
We mix and pour a high-strength concrete enhanced with extra portland cement for superior toughness and long-term durability in outdoor conditions. We construct a 5.5-inch-thick chimney cap (thicker than the typical industry standard of around 4 inches) reinforced with 1/2-inch rebar to provide exceptional structural strength and longevity. The concrete is carefully worked to create a smooth, even finish on the top surface and all sides, while the design incorporates a centered pitch throughout to eliminate water pooling on the cap or near the flues, ensuring consistent drainage and reliable protection year after year.
4. Removing Forms & Caulking
We carefully remove the forms once the concrete has had sufficient time to cure, taking care not to disturb or damage the fresh surface. We then apply a commercial-grade polyurethane sealant to all expansion joints, tooling it neatly for a clean finish that remains flexible and weather-resistant over time. This final step creates a watertight seal at the interfaces while allowing for natural movement, helping to prevent future cracking and ensuring the cap provides dependable, long-term protection.
Our Service Area
Ozaukee County
- Port Washington
- Saukville
- Grafton
- Cedarburg
- Mequon
- Thiensville
North Shore
- Bayside
- River Hills
- Fox Point
- Brown Deer
- Glendale
- Whitefish Bay
- Shorewood