Custom Chimney Chase Cover

Framed chimneys — the boxed chases common on many Missouri homes — are topped with a metal chase cover instead of a masonry crown. When that cover rusts through or pools water, everything below it gets wet. A custom cover, sized and sloped correctly, fixes it for good.

Signs you may need custom chimney chase cover

• You see rust streaks running down the chase from the top
• The metal top is dented, pooling water, or rusted through
• Water is getting into the chase or the firebox below
• The current cover has no slope and holds standing water
• The cover is the wrong size and doesn't overhang the chase

What we check first

Good work starts with looking. Before we recommend anything, here is what we examine:

• Chase dimensions for a custom-fit cover
• The number and position of flue penetrations
• Rust damage on the old cover and any water already inside
• Whether the chase framing beneath has taken water damage
• The slope and overhang needed to shed water

How the work goes

Materials & options

Stainless steel resists rust and is a durable standard; copper is a long-lasting premium option. A proper cover is cross-broken or sloped so water runs off instead of pooling, with sealed collars where the flues pass through.

What can change the scope

Every chase is a little different, so covers are made to fit. Size, number of flues, and the condition of the framing beneath the old cover all factor in. If water has already damaged the chase top, that gets addressed too.

Missouri considerations

A flat, rusting chase cover is a Missouri classic — it holds rain and snowmelt until it rusts through, then feeds water straight into the framed chase. A sloped stainless or copper cover ends that cycle.

Repair or replace?

A rusted or flat cover holding water should be replaced with a properly sloped custom cover. Patching a rusted cover rarely lasts a season, so we build a new one to fit.

Keeping it in good shape

Check the cover and its seams yearly, especially after hail. Stainless and copper hold up well, but sealant at the flue collars is worth keeping an eye on.

Why water is the problem behind most chimney repairs

Almost every masonry chimney repair traces back to the same culprit: water. A chimney sheds rain through a layered system — the crown throws water off the top, the cap covers the flue opening, the flashing seals the roof joint, and sound mortar joints keep the brick from soaking it up. When any one of those fails, water gets in, and Missouri's freeze-thaw winters do the rest, expanding inside cracks and joints until a hairline gap becomes spalled brick or a leak on your ceiling.

That's why the honest first step is finding where the water actually enters, not sealing the nearest stain. A leak that only shows in wind-driven rain points to flashing; one that appears after any rain often points to the crown or brick. Repairs that last address the entry point and match materials to the existing masonry — mortar matched in strength and color, brick matched in size and profile. Once the water path is closed, breathable waterproofing on sound masonry buys years of protection, but it is never a substitute for a real repair.

Frequently Asked Questions

Related reading from our blog

• Chimney Cap vs. Chase Cover: What Is the Difference?
  Compare chimney caps, chase covers, crowns, and flashing, learn which system your Missouri home may have, and understand common water-entry clues.
• How Often Should a Chimney Be Inspected in Missouri?
  Learn when St. Louis and Kansas City homeowners need chimney inspections, what different inspection levels cover, and which warning signs should not wait.
• A St. Louis Chimney Maintenance Calendar
  Plan chimney care through St. Louis seasons, from spring leak observations and summer repairs to fall preparation and winter operating checks.