Whether you depend upon your fireplace for heat or just enjoy the ambiance of a flickering flame on a winter's night, it's vital that you make sure the chimney is safe. Otherwise, you could be endangering your home by courting disaster in the form of a chimney fire. Most chimneys have a liner of some sort, usually of clay or a metal like steel. Some chimneys have no liner—just the exposed brick. The following guide can help you determine if it's time for you to get a new liner.
Sign #1: Decaying mortar
Clay liners and chimneys without true liners have mortared joints. Over time this mortar begins to crack and crumble. This occurs much more quickly on the inside of the chimney where the mortar is exposed to heat. It's nearly impossible for a worker to get into the chimney to fix the crumbling joints. In this case, your best option is to have a metal liner installed.
Sign #2: Broken masonry debris
Another sign for clay and masonry lined chimneys is actual brick debris inside the fireplace. This occurs as the bricks or clay deteriorates and begins to shed pieces of itself. This can be due to age or simply because the heat and corrosive elements in the smoke are causing the masonry to deteriorate quickly. If you find chips, don't use the fireplace again until you have had a professional inspection.
Sign #3: Visible corrosion
Metal liners can sometimes develop corroded sections, usually because of the acids in the soot and creosote buildup. This corrosion is typically found during an inspection or full cleaning, although the technician may need to use a camera to get a clear view of the liner and to verify the damage. Once corrosion begins, there is no fix. You will need to replace the liner to ensure the chimney remains safe to use.
Sign #4: Cracks or splitting
Metal liners sometimes fail by developing a crack or a split. This is highly dangerous and can lead to chimney fires. Much like corrosion, these cracks aren't easy to see without the help of a camera. This is why you need to schedule an annual inspection and cleaning.
When choosing a new liner, you may want to opt for stainless steel. You won't have to worry about masonry problems anymore, and unlike other metals, stainless steel resists corrosion and most other common forms of damage. Talk to a chimney repair tech like those at Excel Chimney & Fireplace Service for more help.