Metal chimney that touches wood framing creates hazard
Q: When I bought my home two years ago, I hired a home inspector to find all the defects. Now that I’m selling the property, the buyers hired their own inspector, and the new report contains information not disclosed by my inspector. According to the new report, the fireplace chimney is touching the wood framing in the attic, and a photo in the new report shows this. The new inspector says this is a fire hazard. Before investing in costly repairs, I want to be sure the new report, rather than the old one, is correct. What can you tell me about metal chimneys in attics?
A: Disparities among home inspection reports are to be expected, due to differing levels of experience among inspectors. In this case, the findings of the second inspector would seem to be correct.
Metal chimneys should never be in direct contact with combustible materials. In most cases, the clearance requirements are listed plainly on the chimney itself. Standard clearances are usually 1 or 2 inches. These specifications may be stamped into the sheet metal or printed on an attached label.
When a hot metal chimney touches a wood surface, the kindling temperature of the wood is gradually lowered, owing to a process known as pyrolysis. Over a period of years, the temperature at which the wood will ignite is slowly reduced. Eventually, the heat of the chimney itself can cause an attic fire.
To ensure adequate fire clearance in your attic, have the chimney evaluated by a certified chimney sweep. A qualified
sweep can make sure your chimney complies with all pertinent fire safety requirements.
Q: The home I’m buying has a condition that I regard as extremely dangerous. The exhaust pipe for the water heater terminates about 3 feet from an openable bedroom window.
When I asked the seller to have this checked by a plumber, he insisted that the exhaust pipe was approved when the building was constructed. To make a long story short, he refuses to do anything about the exhaust pipe and maintains that it is not a problem. How can I know for sure if the water heater exhaust is hazardous?
A: Flue pipes for gas-burning fixtures, such as water heaters and furnaces, are required to terminate no closer than 4 feet from an openable window. This is to prevent exhaust gases, which could include carbon monoxide, from venting into the building.
Approval at the time of construction is no guarantee that this or any other building condition is safe or legal. What you describe sounds hazardous and will probably require that the height of the flue pipe be extended above the level of the roof. You should continue to insist that the seller have the exhaust pipe professionally evaluated.
To improve your negotiating position, have the property fully evaluated by a qualified home inspector. A competent inspector will most likely alert you to additional conditions for the seller to contest.