Your chimney cap, crown, and liner are the three parts that protect it from water, animals, and heat. The cap covers the flue opening, the crown sheds water off the top, and the liner shields your home from heat and combustion gases. When any one fails, water or heat gets where it shouldn’t. Chimney Sweep Squad installs and repairs all three across McHenry, IL. Call (815) 420-6665.
What each part does
Chimney cap: the metal cover and screen on top of the flue. It keeps out rain, snow, birds, squirrels, and leaves, and its spark arrestor stops embers from landing on your roof. A missing cap is one of the most common causes of chimney problems.
Chimney crown: the sloped concrete or mortar slab at the very top that sheds water away from the flue and brick. A cracked crown funnels water straight into the chimney, so crown repair is one of the highest-value fixes we do.
Chimney liner: the flue lining that contains heat and carries combustion gases out safely. A cracked clay liner or an unlined chimney is a fire and carbon monoxide risk, and relining with a stainless steel liner restores safe venting.
When you need this work
- No cap, or a rusted, bent, or missing-screen cap
- A cracked or crumbling crown, or water stains on the ceiling near the chimney
- A chimney fire, cracked flue tiles, or an unlined chimney
- Installing a new stove or insert that needs a correctly sized liner
Relining explained
If an inspection finds cracked flue tiles or no liner at all, relining installs a continuous stainless steel liner sized to your appliance. It restores a safe, smooth path for smoke and gases and improves draft. We size the liner to the fuel and appliance, because an incorrectly sized liner causes draft and condensation problems.
What affects the cost
A cap is a small job; crown repair is mid-range; a full reline is a larger investment that depends on chimney height and liner size. We quote each after inspecting, and we will tell you if a simple cap or crown repair solves the problem without a reline.
Cracked liner after a chimney fire
If you have had a chimney fire, the flue liner may be cracked even if the chimney looks fine from outside. Do not use the fireplace until a Level 2 inspection checks the liner. A cracked liner can let the next fire reach your home’s framing. See our emergency guide.
Frequently asked questions
How much does a chimney cap cost?
A standard single-flue stainless cap is an affordable job; custom multi-flue or decorative caps cost more. Given that a missing cap lets in water and animals, a cap is one of the best-value protections you can add. Call for a quote on your flue size.
What happens if my chimney has no cap?
Without a cap, rain and snow pour straight into the flue, birds and squirrels nest inside, leaves and debris cause blockages, and embers can escape onto the roof. A cap prevents all of these for a small cost.
How do I know if my chimney crown is cracked?
Signs include visible cracks on the top slab, pieces of concrete in the firebox or on the roof, water stains on interior walls or ceilings near the chimney, and spalling brick just below the crown. An inspection confirms it.
What is a chimney liner and why does it matter?
A liner is the inner lining of the flue that contains heat and channels smoke and combustion gases out of your home. A cracked or missing liner lets heat reach nearby framing and can leak carbon monoxide, so a sound liner is essential for safe use.
When does a chimney need to be relined?
A chimney needs relining when the flue tiles are cracked (often after a chimney fire), when there is no liner, or when you install a new appliance that requires a different liner size. A Level 2 camera inspection shows the liner’s true condition.
Are stainless steel liners better than clay tile?
Stainless steel liners are durable, continuous with no joints to crack, and can be sized precisely to your appliance. They are the standard choice for relining and for connecting modern stoves and inserts. Clay tile is original to many older chimneys but cracks over time.
Can a damaged crown be repaired, or does it need replacing?
Minor crown cracks can often be resurfaced with a flexible crown sealant. A crown that is badly broken or deteriorated needs to be recast. We recommend the least invasive fix that will actually last, and tell you honestly which one you need.
Will a new cap or liner improve my fireplace’s draft?
Often yes. The right cap can reduce downdrafts, and a correctly sized liner gives smoke a smooth, insulated path out, which improves draw and reduces smoke spillage into the room. Draft problems sometimes trace directly to a missing or wrong-sized liner.
Protect the top of your chimney
A cap, a sound crown, and a safe liner prevent the most expensive chimney problems. Get yours checked, 7 days a week.
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Published November 10, 2026 · Reviewed by Joseph Ino, Founder & Master Chimney Technician, Chimney Sweep Squad