Prefab Chimney Housing & Chase Repair

Repair and Restoration for Prefab Chimney Housings Above the Roofline

Factory-built fireplaces commonly vent through a manufactured chimney system that extends through the roof inside a square or rectangular exterior housing, often called a chimney chase. This service is specifically for that exterior housing and the components around it above the roofline - not the interior firebox or refractory panels.

AirPlease Missouri Chimney Services inspects deteriorated prefab chimney housings and provides repair or restoration options based on the condition of the exterior structure, chase cover, termination area, flashing, coatings and accessible metal components.

Common Prefab Chimney Housing Problems

• Rust or corrosion on the exterior metal housing.
• Peeling, failing or weathered exterior coatings.
• Loose, separated, bent or deteriorated housing panels.
• Water intrusion around the chase cover, seams or roofline.
• Rusted, damaged or improperly fitted chase covers.
• Deteriorated sealant around storm collars or termination components.
• Open seams, gaps or exposed areas that allow weather into the housing.
• Deterioration around the base of the housing where it meets the roof.

Exterior Housing Restoration

When the existing prefab chimney housing remains structurally serviceable, restoration may be possible instead of complete replacement. The approved scope may include cleaning and preparing affected surfaces, removing loose material, treating accessible rusted areas, sealing appropriate exterior joints, priming and applying a durable exterior coating or paint.

The exact repair depends on the material and condition of the existing housing. Areas that are severely rusted through, loose, structurally deteriorated or no longer suitable for restoration may require replacement rather than coating over the damage.

Chase Cover Replacement

The chase cover is the metal cover at the top of the prefab chimney housing. When it rusts, separates, holds water or no longer protects the chase properly, replacement may be recommended. AirPlease Missouri Chimney Services can install a properly sized stainless steel chase cover when included in the approved scope.

Stainless steel is commonly used for replacement chase covers because it provides significantly better long-term corrosion resistance than basic galvanized steel.

Termination, Storm Collar and Weather Protection

The top of a prefab chimney system includes the manufactured chimney termination and surrounding weather-protection components. During housing service, accessible areas around the termination, storm collar and chase cover can be evaluated for visible deterioration, failed sealant or conditions that may allow water into the chase.

The factory-built chimney pipe and termination are part of a listed manufactured system. Housing repairs do not mean unrelated chimney components can be substituted. Any work involving the manufactured venting system must remain appropriate for the specific fireplace and chimney system.

Roofline and Flashing Areas

Water can also enter where the prefab housing meets the roof. Accessible exterior conditions around the base, flashing and sealant can be documented during inspection. If roofing work outside our masonry or chimney scope is required, a qualified roofing contractor may be needed for that portion of the repair.

When Replacement May Be Necessary

Some prefab chimney housings have deterioration that extends beyond surface rust or coating failure. If metal panels are rusted through, badly deformed, unstable or extensively deteriorated, partial or complete housing reconstruction may be the more appropriate solution.

The goal is not to hide deterioration with paint. The goal is to determine what can be properly restored, what should be replaced and how to protect the chimney chase from continued weather exposure.

Frequently Asked Questions

Restore and Protect the Exterior Prefab Chimney Housing

A deteriorated prefab chimney housing can expose the chase to continued moisture, corrosion and weather damage. AirPlease Missouri Chimney Services can evaluate the exterior housing, chase cover, termination area and other accessible roof-level components and recommend an appropriate repair or restoration plan.