Chimney Caps

Seattle chimney caps are fitted over the flue tile at the top of a chimney and have a variety of uses. They can be used to prevent Seattle rain from going down the chimney into the home, prevent rain and ice buildup from causing deterioration of the chimney crown and flue liner, block bats, birds, and wildlife from entering or building nests in the chimney, increases the downdraft, or improves damping. Most caps are installed with the chimney or can be found through a Seattle manufacturer. The only reasons not to use a cap from a Seattle manufacturer are if there is a problem with the draft or if the manufacturer is out of business when a replacement cap is needed.

The draft refers to the control of air flow and pressure within the Seattle chimney flue that allows your waste gases to rise out of the chimney while allowing fresh Seattle air to replace this and allow proper combustion. A number of difficult to control factors can influence the draft in a chimney. Most notable, areas with high or constant Seattle winds can find the draft being disrupted purely from the weather. There are specific types of caps that are designed to help rectify this.

Dampers are used to close off the chimney when not in use. Most Seattle chimneys have a damper located in the “neck” of the chimney which allows the Seattle owner to close off the chimney and prevent outdoor Seattle air from coming into the home. In older Seattle chimneys the damper is typically cast-iron. This means there is a metal-to-metal seal which allows leakage at the edges and becomes even less reliable once water has rusted or warped the metal. The other problem with these older dampers is simply their location. Being so far down the chimney they do nothing to prevent Seattle rain from coming down to the level of the damper and they leave a lot of room for bats, birds, or other wildlife to build a home within the confines of the chimney. If needed, caps are designed with a built in damper to close off the chimney from the very top.

 

Metal chimneys usually require a cap as there is nothing to prevent rain from running right down the flue into the Seattle home. This moisture inside the flue can cause the house to have a musty odor in warm or humid Seattle weather. Masonry chimneys can be more complicated to cap than the metal ones as improper capping can lead to reduction of the draft, wrong sizes can cause discoloration of the chimney crown as soot builds up and is washed down the sides of the chimney during Seattle rain, and high winds can cause the cap to need to be replaced frequently if not attached properly. Sizing can be especially difficult in Seattle masonry chimneys with multiple flues. Specialty caps are used in the instance of a multiple flue chimney. It needs to take into account the size of the chimney, the size of the area around all the flues, and the height of the tallest flue in order to fit correctly.

Depending on your Seattle chimney needs, there are different caps to serve a multitude of purposes. The basic Seattle chimney cap is made with screens to prevent animals entering the chimney and the top to stop rain. In some cases these basic caps can help block Seattle wind and actually increase the draft for some chimneys. In cases where draft issues are severe, there a number of draft increasing caps that are formed by redirecting the wind, vacuum caps, or made with electric fans. The caps with dampers included have a cable that runs down the inside of the chimney and are easily controlled by an indoor lever to open or shut the damper. There are deluxe caps that can be made for unusual sized Seattle chimneys, especially useful in homes with many appliances being vented through a single chimney or older homes. For Seattle homeowners that seek a specific look for their chimneys, custom caps can give a unique look to a home.

While a cap is being considered or installed is the prime time to have your chimney inspected for any needed repairs. A lack of or improperly placed cap can be a cause of Seattle rain deteriorating the brickwork of the chimney on the outside. Seattle animals frequenting the chimney area will also work away at the mortar between the bricks causing areas in the chimney that leak, loosening bricks, and decreasing the draft. It is more common to need to repair the mortar joints than to replace bricks, but those joints are necessary as they bear the weight of the wall, hold the bricks together, and make a water proof seal between the bricks. These joints also represent a weak-link in the masonry chimney because Seattle water getting between the bricks can cause chipping, spalling, or flaking or the brick which can lead to even more extensive repairs.

 

Repointing/tuckpointing may be necessary to replace and repair the mortar. A Seattle professional can make sure that the proper type of mortar is used to maintain the stability of your chimney and to preserve the charm of the contrasting colors from the bricks and mortar.