Rusty Chimney

A rusty chimney is another common issue for Minnesotans. It is often due to the extreme weather that the Minneapolis – St. Paul area often experiences, especially in the eastern suburbs. Rust usually starts with the chimney cap or chase cover with streaks of orange or reddish-brown stains dripping down the crown and exterior brick or stone masonry. But other metal components, such as the fireplace damper and flashing, are also particularly vulnerable to rust when exposed frequently to oxygen and moisture. Additionally, rusting may occur in the firebox, flue, and exterior masonry without regular cleanings.

To preserve the integrity of your masonry or manufactured chimney and fireplace, contact Twin City Fireplace at the first sign of rust. In addition, you can reach us at (952) 941-2685 (Minneapolis/West Loop area) or (651) 204-0112 (St. Paul/East Loop area) to schedule a professional chimney inspection so we can determine whether the component needs repair or replacement.

Why Is My Chimney Rusty?

When you first notice your rusty chimney, it's essential to prevent further damage immediately. Rust literally will "eat" its way through masonry and metal, weakening its structural integrity, which can result in costly repairs and premature replacement.

There are a few different reasons why chimneys develop rust, but the most common cause is moisture. Condensation can cause some metals, like aluminum, iron, and galvanized metal, to corrode more quickly than others, like copper or stainless steel. This is why it's important to make sure your chimney is well-ventilated. Since the Twin Cities Area has both icy and wet winters with humid summers, we often recommend clients replace damaged components like a chimney cap or flue liner with stainless steel, a natural water, pest, and rust-resistant material.

How Do You Get Rust Off a Chimney?

When you see rust on your chimney, you may wonder how to get rid of it. It’s a good idea because rust can cause severe damage to your chimney. So, removing it as soon as possible will prevent further damage to the stack. There are a few different ways to remove rust from a chimney. Still, it's best left to the experienced masonry professionals at Twin City Fireplace to avoid further damage. However, if you are handy around the house and insist on trying to DIY first, one popular method is to use a wire brush. It will quickly remove any rust on the chimney's surface, but you must be careful to avoid damaging the masonry or component, or it will worsen the issue. Another method is to use a chemical rust remover.

Again, you must be careful here too. Because if you use the wrong rust remover for your chimney, it may remove more than just the rust. After rust removal, waterproofing the chimney will create a barrier preventing water and moisture from seeping in and causing rust. A word of caution: if the rust has damaged the component, such as warping, chafing, or holes, it must be replaced.