Company Blog

All About Chimney Crowns

From our years in experience of working in the chimney industry, All Seasons Chimney understands the problems that water can cause to a fireplace and chimney system. In fact, the Chimney Safety Institute of America (CSIA) named water as the biggest enemy of a masonry chimney. Except for stone, all masonry chimney construction materials suffer from accelerated deterioration when exposed to water for an extended period of time. Preventing water penetration of chimneys is one of our most important duties as chimney experts, and we know how to best keep the water out of your chimney. One of the most simple ways to stop water from entering your chimney in the first place is the installation of a chimney crown. We would like to tell you more about chimney crowns and how they can protect the masonry materials of your chimney.


What exactly is a chimney crown?

Also known as a chimney wash, a chimney crown is the top part of a masonry chimney. Constructed from mortar, the chimney crown covers and seals the top of a chimney from the flue liner to the chimney edge.

Why do I need a chimney crown installed on the top of my chimney?

Without a chimney crown, your chimney is open to rainwater and water from melted snow. This water will penetrate the bricks and mortar of your chimney. In the winter, this water repeatedly freezes and thaws, and this process causes problems. When water freezes, it expands as much as 10 percent. This can create cracks in the bricks and mortar, which worsen each time this water freezes. Even tiny amounts of water can cause this type of spalling damage. Eventually, if left unrepaired, the bricks and mortar can become so deteriorated that your chimney is no longer structurally sound.

If a chimney crown is made from mortar, how is it protected from spalling damage?

Since the chimney crown sits on the top of your chimney exposed to all of the elements of weather, it should be sealed with a durable waterproofing treatment to protect it from water penetration. A customized chimney crown from All Seasons Chimney is also constructed from a Portland cement-based mixture that is designed for years of weather abuse.

How can I tell if my chimney crown is properly constructed and installed?

A properly built chimney crown should have a slope to best protect your chimney from water damage. Your chimney crown should provide a downward slope to direct water from the flue to the edge of the crown. There should also be an overhanging drip edge to direct water from the crown away from the chimney to help prevent any erosion of the bricks and mortar in the vertical surfaces of the chimney. This overhang should project beyond all sides of the chimney by a minimum of two inches for best protection from water damage.

In need of a chimney crown? Contact All Seasons Chimney to schedule a custom installation of a crown for your chimney.

Seal Your Chimney Flashing Before It’s Too Late

Summer has officially come to an end, and now it is time to look ahead to the exciting change of seasons. The colorful leaves and chilly weather has everyone in the season spirit. The upcoming holidays are also on a lot of people’s minds as the end of the year approaches. This is usually a happy time of year, and no one wants to think about keeping their roofs from leaking, or even about a roof that is already leaking. However, now is the best time to take care of any roof leaks because the frigid winters in the Hudson Valley make roof conditions too dangerous to work on until spring comes around again.


Chimneys are responsible for a surprising number of water leaks into the house. Without a chimney cap, water can enter directly through the top of the chimney. If the masonry is improperly sealed, water can travel through the brick and mortar, right into the house. While these issues deserve a column of their own, leaky flashing is the topic of today.

Flashing is a covering used to stop water from leaking beneath the roof shingles. It can be found anywhere the line of the roof ends, such as around dormers or sky lights. Chimney flashing prevents water from leaking in where the chimney protrudes from the roof. Generally made of aluminum, the flashing on a chimney is much more complex than flashing on other areas of the roof. It consists of four woven layers of flashing all sealed with mortar to prevent premature decay.

While the mortar that holds the flashing together holds up longer than other materials some nonprofessionals use on their flashing, it is not indestructible. If not maintained properly, mortar will eventually deteriorate. It is a porous material, so when exposed to water, the mortar absorbs it readily. Then, around winter time, the saturated mortar expands and contracts during the freeze and thaw cycle. This inevitably results in cracks, and in turn, a leaky roof. In order to prevent a leaky roof and to maintain the integrity of the flashing, you can have your mason seal the flashing around the chimney.

Applying a sealant to your flashing keeps the aluminum and the mortar out of direct contact with the elements. The waterproof sealant prevents water from seeping into the mortar or even into your home. For the ambitious do-it-yourself types, be aware that poorly serviced flashing will not last as long as properly maintained flashing, and it could even cost you thousands of dollars in water damage repairs.

If you live in the Hudson Valley area of New York, contact All Seasons Chimney for a professional consultation. Take care of your home and chimney before it is too late.