How To Keep Your Gas Fireplace Insert From Corroding Your Chimney

Fireplace inserts that run on natural gas or propane instead of wood provide heat and beauty without the hassle of lugging around logs. Many models fit directly into masonry fireplaces with few modifications to the chimney, especially if there's already a metal or concrete liner. However, missing a few design improvements and skipping routine maintenance chores can lead to a chimney so corroded from the inside out that it's a danger to the rest of the home.

Routine and Thorough Cleaning

While burning wood produces creosote that does little damage to the chimney itself, gas fuels produce invisible fumes and corrosive deposits on the inside of the chimney that lead to corrosion. The damage affects all sorts of chimneys by

  • Eating away any protective coatings, such as galvanization, on vent pipes and metal liners
  • Causing the masonry between bricks or blocks in an unlined chimney to break down, leading to a collapse
  • Attracting water in the form of condensation, which ruins all forms of chimney material from metal to corrosion-proof clay liners

Since even clay chimney liners eventually flake apart or crack due to moisture attracted by the byproducts on your chimney's walls, it's necessary to schedule at least one cleaning a year. If you use the gas fireplace insert on a daily basis for regular heating, you may want a chimney sweep to visit every six months instead. It's a lot more affordable to pay for occasional cleaning visits than to have the chimney relined or completely rebuilt.

When you're dealing with the residue left behind by a gas burning appliance, it's safer for a professional to handle the cleaning process. You don't want to create a lot of dust out of those corrosive deposits, which happens when you use one of the inexpensive chimney cleaning brushes on the market. A chimney sweep will bring along vacuum systems and less damaging brush and air pressure tools to clean the walls without making a mess.

Inspection During Maintenance

Hire a chimney sweep that can give you a report on the condition of the entire structure during the visit too. With a basic camera system, it's easy to do a quick inspection to look for cracks and other signs of underlying damage. Even if you already have the gas appliance serviced and inspected each year, these visits may not include any attention for the chimney.

Insulate the Chimney

Aside from managing the waste products of gas combustion, consider installing insulation around the gas insert and up into the chimney opening. This is especially important when using a liner or length of stove pipe that sits in a larger opening from an existing masonry chimney. All that cold air around the heated metal causes condensation between the masonry and the liner or pipe, resulting in damage to both parts of the chimney. Make sure you use an insulation product rated for high heat uses, such as expanded rock batting.

Install a Liner

Finally, it's never too late to protect a masonry chimney by adding a liner, even if you've been using the fireplace insert for years. Metal is smooth and easy to clean regularly, while cement coatings are far more corrosion resistant. Clay liners are easy to clean and resist the corrosive effects of the deposits, but they're also harder to install and tend to cost more. Even basic metal liners will last for decades with regular professional cleaning and prompt repairs if any signs of rust or damage shows up. Since a leaky chimney corroded by gas by-products can allow carbon monoxide and other dangerous fumes into the house, it's worth the investment to get some form of chimney liner.

For more information or to schedule a cleaning or inspection, contact a company like Early Times Home Solutions.