HomeownerHelpful Info: Home Maintenance

Chimneys & Fireplaces

Chimneys & Fireplaces Educational Content

The purpose of a chimney cleaning is to remove creosote and any debris that could cause a chimney fire. A chimney sweep will use a variety of special tools to remove debris and make the inspection process easier. The National Fireplace Institute (NFI) and the Chimney Safety Institute of America (CSIA) recommend annual chimney safety inspections. Your chimney should be swept as necessary, or when the creosote reaches one-eighth of an inch of buildup. Creosote is highly flammable, and a chimney fire burns very hot. Its flames can extend ten feet above the top of the chimney. Chimney fires can quickly spread to the roof and attic and destroy the entire house. If a chimney fire starts, get everyone out of the house and to safety as quickly as possible, and then call 911.

The National Fire Protection Association (NFPA) designates three levels of chimney inspection:

Level one inspection. This basic inspection is what you’ll need if your chimney hasn’t changed at all since the last inspection. The technician will inspect the accessible portions of the chimney’s interior and exterior. They should also take a look at the chimney connection. If the technician finds anything blocking the chimney, they’ll remove it.

Level two inspection. A level two inspection is required if you’ve made changes to the chimney, fireplace, or how you use them. If you’re the new owner of the house or if the chimney has been damaged, a level two inspection is what you’ll need. This type of inspection includes everything in a level one inspection plus an examination of every accessible part of the chimney. A level two inspection should also include a visual inspection of the chimney’s interior. Most technicians do this with a video scan.

Level three inspection. A level three inspection is only necessary when serious hazards are suspected. It includes everything in a level two inspection as well as some demolition, as needed, to fully inspect areas of concern.

The byproduct of burning wood is creosote, or soot. It’s essentially unburned fuel formed when flue gases are too cool and condense into a grimy buildup. As the creosote and smoke travel up the chimney, some of the highly flammable creosote sticks to the insides of the chimney. Over time, that creosote buildup can create a chimney fire hazard.

One way to limit the amount of creosote in your flue is to make sure you have enough airflow in your house. As the air in the chimney moves up and out into the atmosphere, it needs air brought in to replace it. Modern homes are sealed and insulated well. This is great for energy efficiency, but it can cause issues with chimneys. As a house is sealed up, less air gets in, and the flue gases vent more slowly. This gives the gases time to cool and condense, resulting in more creosote. Beyond ensuring sufficient airflow, take care to only burn dry, seasoned firewood. Fresh, damp logs contain moisture that will cause the fire to smolder. The smoke from a smoldering fire releases gases that contribute to creosote buildup. Split whole logs in halves or quarters to make sure the wood is dry both inside and outside.

A chimney cap protects the chimney from pests and rain. Chimney caps are usually made from stainless steel or copper. Uncapped chimneys offer warm, open spaces to birds and animals who may nest in the chimney space. This can lead to unpleasant odors, among many other problems. The presence of the nesting materials in the chimney also poses a fire hazard. Another advantage of the chimney cap is that it keeps water (and ice, in the winter) out of the flue. Chimney caps are also important for safety. They help prevent sparks and stray embers from igniting the roof or flying down into your yard.

In particular, metal chimneys need to have a chimney cap. Metal chimneys are made from two or three layers of metal with insulation placed between each. A chimney cap prevents water and moisture from accumulating between the layers. This reduces the chances of the chimney failing. You’ll find lots of choices for chimney caps on today’s market. Stainless steel, copper, crown mount, multi-flue, and cap/damper combination are all popular options. To determine the best type of cap for your chimney, talk to a professional.

Minor repairs. As they’re cleaning your chimney, your chimney sweep will let you know about any areas that need repair. Some chimney cleaners can also fix small problems with the chimney or firebox. Fixing or replacing a broken damper or chimney cap, for example, are common repairs. If you want your chimney cleaned and inspected at the same time, choose a company that provides both of those services. You can also keep an eye out for possible problems by checking the exterior of your chimney for signs of damage.

Masonry repairs. Most chimney companies have bricklayers on staff to handle chimney restoration projects. Masons can fix a variety of issues, from spalling and missing bricks to cracked and failing mortar. If the damage is beyond repair, the bricklayers can rebuild either a section or all of the chimney.

Leaning chimneys. If your chimney begins to lean away from the house, you’ll need to consult a professional for help. Depending on the cause of the problem and severity of the lean, the chimney may need to be rebuilt or reinforced.

Liner replacement. Chimney liners provide important protection from heat and combustible materials. In most cases, masonry chimneys have terra-cotta liners. Initial building defects, damage, or deterioration over time may warrant chimney liner replacement. Chimney experts typically use flue sealants to fix liner problems. If the liner needs to be totally replaced, the replacement is usually made of stainless steel.

Chimney cleaning is seasonal, and winter is typically the busiest time of the year. Since scheduling an appointment can be difficult in winter, plan to get your chimney cleaned in the off-season. A professional can easily spot small problems and maintenance issues before they turn into huge repair bills or safety issues that could potentially put your entire home in jeopardy.