The answer can vary widely based on a home's age and design. As with any type of remodeling project, assume that every structure is load-bearing until confirming otherwise with a structural engineer. Almost all modern homes have chimneys that are fully independent from the rest of the home's framing. As a result, they don't bear any load beyond their own weight. However, many historic homes built prior to the 1900s contain load-bearing chimneys that tie into the surrounding roof and floor joists. If possible, use a home's blueprints or look for chimney connections that indicate load-bearing qualities to get your answer.

In many cases, it is worth repairing an old fireplace. You can repair any portion of the fireplace, and even extensive repairs will usually cost less than a full replacement. Most fireplace repairs cost around $600 and top out around $2,500. Replacing your fireplace will cost around $2,500 and reach as high as $4,000. Not only will fireplace repair save you money in most cases, but the process is also much less invasive and time-consuming, so you’ll only have to set aside one day to be home for the work rather than multiple days.

Costs depend on stove type, venting complexity, and additional features like hearth pads or decorative finishes.

You should never block both the top and bottom of your chimney. Proper airflow is essential because the temperature inside the chimney will still fluctuate as your house warms and cools. Moisture can build up without ventilation, leading to dampness in your walls over time. Blocking the top prevents debris and animals from entering, but the chimney still needs air circulation to avoid condensation issues. Allowing the chimney to breathe maintains the health of your home and prevents long-term damage.