Our Company Blog

Advantages of a Top Sealing Damper

Chimney and fireplace technology continues to make advances, helping homeowners save money and run their appliances with maximum energy efficiency. One such chimney component that continues to grow in popularity is the top sealing damper.


This clip is courtesy of Richie Baxley at Environmental Chimney Service in Asheville NC.

What is a top sealing damper?

In most fireplaces, the damper can be found at the top of the firebox. The purpose of this damper is to separate the flue from the firebox, keeping the warm air inside your home in while keeping drafts and cold air out.

Unlike a normal damper, top sealing dampers are located at the top of the flue. When closed, they seal off the entire flue and chimney structure from the outside. This prevents any cold air, moisture, debris, or animals from entering the flue when the damper is closed.

Advantages of a top sealing damper

One of the biggest advantages of the top sealing damper is that they help keep chimney structures warmer. This prevents your chimney from being “cold”, which can cause smoke to blow back into your home when you attempt to start a fire. Likewise, having the flue closed to outside air means that rooms near the chimney or flue are less likely to experience dramatic shifts in temperature in the summer or winter months.

Because the top sealing dampers close off the entire flue, they are often considered a more energy efficient option than traditional dampers. They also prevent downdrafts or “whistling” chimneys, which can occur with regular dampers even when the damper is closed. Likewise, when the top sealing damper is closed there is no loss of heated or cooled air from your home, and outside air in the chimney will not affect your interior temperature.

Do top sealing dampers need chimney caps?

Top sealing dampers work as a replacement for chimney caps. Because they seal off the top of the chimney when not in use, it protects your chimney from moisture, leaves, branches, and other debris from falling into the flue.

When closed, the dampers are also effective at keeping birds, small mammals, and raccoons out of the flue and chimney structure. When the fireplace is in use and the damper is open, the smoke from the fire acts as a natural deterrent to keep animals away from the chimney. In addition, the design of many top sealing dampers will keep large animals such as raccoons out even when the damper is open.

Because the chimney is essentially open when the damper is open, it is extremely important to close top sealing dampers when the fireplace is not in use. Without doing so, water, debris, and animals – all of which damage the fireplace and chimney – have easy access to your chimney.

If you’re interested in learning more about top sealing dampers and whether or not it would be the right choice for your chimney system, contact Pristine Sweeps today. Our highly trained and knowledgeable staff would be happy to discuss the pros and cons of top sealing dampers and whether or not it would be a good fit with your fireplace needs.

How to Spot Winter Masonry Problems

During the cold months of winter, most people retreat inside to spend time with their families around a roaring fire. Unfortunately, the freezing temperatures that make us want to stay inside can also have a negative effect on our chimneys.

Steep drops in temperatures, freezing rain, sleet, snow, ice, and harsh winds can all contribute to chimney damage during the winter. In addition, these winter weather conditions can make existing chimney damage worse or contribute to accelerated decay.

Below are several common winter masonry issues, what causes them, and how to prevent them from happening or fix any damage they cause.


The freeze thaw cycle

The freeze thaw cycle is the primary cause of masonry damage during the winter. Because bricks and mortar are naturally porous substances, they are meant to absorb small amounts of water. Older or damaged bricks with cracks or holes may absorb even more. When bricks and mortar absorb water from rain or snow and the temperature drops below freezing, the water in the masonry also freezes. The water expands as it freezes, creating larger areas of damage. When the ice melts so does the water within the masonry, leaving larger holes that can now be filled with even more water. This process is called the freeze thaw cycle.

Signs of damage to the masonry of your chimney may include brick that is chipped, cracked, missing pieces, crumbling, or otherwise falling apart. The best way to protect against water damage is to have your chimney regularly inspected and maintained. If your chimney has damaged or missing bricks or crumbling mortar, the masons at Pristine Sweeps can repair the damage, and their work is accompanied by a five year warranty.

How to prevent water damage

To further protect your masonry from the damaging freeze thaw cycle, considering having the bricks and mortar of your chimney waterproofed. Pristine Sweeps uses the special Chimney Saver products which are able to prevent water from getting in while still allowing gas to get out. This is different from latex paints and other sealants which no longer let the brick pass gas.

Other masonry problems

While damage to the bricks and mortar of their chimney masonry is often homeowner’s primary concern during the cold months of winter, there are a number of other ways that winter can affect your chimney system’s masonry. One problem that can occur due to a chimney’s height is the stack effect. The Stack Effect occurs when there is a difference in air pressure between the inside and outside of a home. This can be worsened by heavy winter winds creating external pressure on the chimney. The cold air rushing down the chimney may cause smoke to blow back into the home.

If your chimney cap, chimney crown, or chimney chase cover become cracked or damaged, you may notice water entry into your chimney and fireplace. You may notice that the inside of your firebox is damp or that there is a musty smell when the fireplace is not in use. This type of water entry is equally detrimental to a fireplace system in that it effects many of the metal parts of a fireplace. Damaged chimney caps, crows, or chase covers should be repaired or replaced as soon as possible to minimize damage.

If you have questions about how the winter weather is effecting the masonry of your chimney, contact Pristine Sweeps today!