When most people think about a chimney, they picture a chimney sweep on the roof with special tools, checking every brick and every inch of the flue. A home inspection is not that. I do not evaluate a chimney to the level that a chimney sweep does. I look at the chimney the way a home inspector is required to under the New Jersey standards and in a way that helps a buyer understand what they are getting into. A chimney can tell you a lot about the house. It can also hide a lot of problems if you do not know what to look for. It sits out there in the weather every single day. Rain, snow, sun, wind, freeze and thaw. If there is one part of a home that gets beat up more than the rest, it is usually the chimney. So during a NJ home inspection I try to give you a clear picture of what I can see and what it means.
What I look at on the outside
I always start on the exterior because that is where the weather hits first and where many problems begin. I look at the bricks or the stone or the siding on the chimney. I check the mortar joints. I look for gaps, deterioration, missing mortar, loose bricks and any movement. I look for bulging, leaning or any separation between the chimney and the house. A chimney that is pulling away or leaning has usually been doing that for a long time. It is not sudden.
If the chimney is stucco or stone veneer, I look for cracking, gaps around the edges and places where water may be getting behind the surface. These materials can hide moisture issues if nobody is paying attention.
I look closely at the crown at the top. The crown is supposed to shed water. A cracked or poorly built crown is one of the biggest reasons water ends up inside a chimney. Once water starts getting in at the top, it can run down the interior, rust parts, cause staining, damage the liner tiles and weaken the chimney over time.
If there is a metal chase cover on a factory built chimney, I look for rust, open seams, holes and ponding water. A rusted chase cover sends water straight down into the chimney chase.
I also look to see if the chimney should have a cricket behind it. A cricket is a small roof shape built to push water around a wide chimney. If you have a wide chimney with no cricket, a lot of water ends up sitting behind it. This is one of the most common reasons for chimney leaks. It does not look dramatic at first, but the damage adds up.
Flashing and why it matters so much
The flashing around the chimney is one of the biggest problem spots on any home. Flashing is supposed to make a watertight connection between the roofing and the chimney. When flashing is missing, loose, rusted or buried under roofing cement, water gets in. Sometimes the chimney itself looks fine, but the flashing is the real issue.
I look for loose or lifted flashing, gaps between the flashing and the masonry, fresh roofing cement smeared everywhere, rusted metal or missing step flashing. Water entry at the flashing can cause stains in the attic, stains on ceilings and walls in the living space and deterioration of the chimney masonry. It can also rot the roof framing around the chimney.
How I look at the top and the cap
From the roof, from the ground or with binoculars, I look for chimney caps and rain covers. A proper cap helps keep water out of the flue. A missing or damaged cap is very common. Without a cap, rain goes straight down the chimney and lands on the smoke shelf, the damper or the insert. Over time this leads to rust, staining and failure of metal components.
I check to see if each flue has its own cap and if the caps are loose, rusted or damaged. A little rust is usually the first warning sign. Heavy rust means long term water entry.
Looking inside from the fireplace or insert
Inside the home I start at the firebox. I look at the bricks or panels, the mortar joints, the damper and the smoke chamber. I look for cracks, gaps, loose bricks, rust and staining. If you have a metal insert and I see rust on the top or down the sides, that usually means water is coming from the top of the chimney.
When I look up from the firebox, I can usually only see a few feet up the chimney. That is normal for a home inspection. We are not climbing up inside the flue. We look with a flashlight and sometimes a mirror and there is only so much that can be seen.
From that limited view I look for gaps in the liner, missing mortar joints, misaligned tiles, cracked tiles and any open sections. These conditions matter because the liner is supposed to contain heat and exhaust. If the liner has gaps or cracks, carbon monoxide or hot gases can escape into places where they do not belong. This is a safety concern.
I also look at whether the chimney is drafting properly. Heavy smoke staining rolling out of the front of the firebox instead of going up the flue can be a sign of drafting issues, design concerns or past misuse.
What a NJ home inspector cannot see inside the flue
The interior of the flue is not fully visible in a standard home inspection. A chimney sweep uses a camera to see every inch. That is called a level II inspection. Home inspectors are not performing level II inspections. That is not part of the NJ home inspection standards. A level II inspection requires tools, cameras and access that a home inspector does not have during a general inspection.
A home inspection is a visual inspection of what can be safely seen without dismantling anything. I cannot see every tile or every joint inside the flue. So instead I look for clues such as rust, staining, efflorescence, moisture, cracks, odors or heavy soot. These signs can tell me if something inside the chimney may need a closer look by a chimney sweep.
Factory built chimneys and venting for furnaces and water heaters
If the home has a factory built chimney or a metal vent system for a furnace or water heater, I look at the visible metal sections, the slope, the connections and the clearances. Rust streaking, melted plastic nearby or staining around the draft hood can be signs of backdrafting or poor venting. Backdrafting can allow carbon monoxide to spill into the home.
Again I cannot see every inch inside those vent pipes but I can see enough to know if there are warning signs.
Water and long term damage
Water is the biggest enemy of any chimney. It can rust dampers, inserts and liners. It can freeze in cracks and make them larger. It can wash out mortar joints. It can travel into the attic or wall cavities and cause rot or mold. Staining patterns around a chimney tell me a lot about what has been happening over time.
Safety and use
My goal is to help you understand if the fireplace or chimney appears safe for use or if it shows signs of damage or long term issues. I look at the clearance to combustibles, the hearth size, the trim around the opening, the screens or doors and any gas log setups. If I see safety concerns, I say so clearly.
How I explain chimney findings in my reports
In my reports I explain what I saw, why it matters and what can happen if it is not corrected. I also explain what kind of trade usually handles the correction. I do not write vague comments. A proper chimney inspection by a chimney sweep will always be more detailed because that is their specialty. But a good NJ home inspection should give you a strong understanding of the visible chimney conditions and whether age or water has already taken a toll.
If you want to learn more about NJ home inspections
If you are trying to understand what to expect from a chimney evaluation during a NJ home inspection, this information will help.
I am a New Jersey home inspector with more than twenty five years of experience. I do one inspection per day so I can take my time and look at the details. I use thermal imaging, moisture meters and plain common sense to explain what I see. My reports are long and written in the same steady voice you see here.