Cracked panels and worn fireplace parts fixed in Bay Hill

Alterations that take a fireplace out of its listing

Makers draw a clear line around changes to their units. One maker lists actions that void its warranty and that it disclaims responsibility for, including modification of the fireplace, its components, doors, air inlet system and damper control, and use of component parts it did not make or approve.

Past owners and past remodels sometimes altered a unit by trimming a panel, removing a shield or blocking an air inlet. We look for those changes, explain what each one affects and list what it takes to return the fireplace to its intended build.

Inserts inside a factory-built fireplace

An insert placed inside a factory-built fireplace changes how that fireplace heats and vents. One maker's manual warns against installing an insert in its firebox unless the insert maker's instructions specifically state that this fireplace has been tested for use with that insert.

We read both labels and both manuals before an insert is discussed. If an existing insert sits in your prefab unit without that match, we explain what the documents say and what your options are.

How high a factory-built chimney must reach

One maker's instructions follow a familiar rule for the top of the chimney. The top has to stand 3 feet or more above the highest point of its roof penetration, and 2 feet taller than any part of the roof that lies within 10 feet.

Additions and roof changes can put a higher roof section inside that 10-foot circle. If the chimney no longer meets the rule, we explain what the manual allows for extending it with listed sections.

• At least 3 feet above the roof penetration
• At least 2 feet above roof within 10 feet
• Extensions with listed sections only

Getting to the chimney in the attic or chase

Attic and chase access lets us check the pipe joints, supports, firestops and insulation shield along the chimney. Some homes have an attic hatch near the fireplace, and some chases have no access panel at all.

We tell you where access is needed before the visit, and if an opening has to be made in a chase, the estimate says where and how it will be closed.

• Where the attic hatch is
• Whether the chase has an access panel
• Where a new opening would go
• How that opening will be closed