How to Flash a Chimney on a Roof and Design Options to Consider

a brick chimney on a roof

One of the most striking features of a home is often the roof design and chimney style. The best chimney design can provide a visual cap to the roof of a home. It can set a house apart from other homes in the neighborhood. Blended perfectly with the slope and contour of the roof, it can cast a crown of royalty on top of a home.

Choosing the Best Chimney Style

When the fireplace vent system is part of a new home construction, the types of construction are endless. A homeowner should work closely with an architect to match the style with the form and the shape of the house, trying to avoid one that looks like it belongs on another home. When purchasing an existing home with a venting system already built in, the situation changes.

The interior structure will remain the same, but a new visible cap portion can be constructed without a problem. For this discussion, the focus will be on existing structures, providing suggestions on how to pick the best styles for the top portion that shows. There will be a final segment addressing the importance of properly flashing to prevent leaks.

Importance of an Inspection

Before putting on a new cap, get a full inspection. While licensed sweeps are qualified to clean an existing chimney that is in good repair, it is best to hire a qualified contractor to do the inspection. Homeowners need to make a note of what type of liner is used, and specifically what the condition of it is.

The best time to make changes in the lining wall is when adding a new top portion. If there are any potential problems with the liner wall, this is the best time to install a new metal lining. Depending on the age of the home, it is always worth considering a new liner. The consequences of a compromised liner can obviously be devastating.

Color and Material

a new red chimney on a roof

Once the chimney has passed an inspection, it’s time to pick a style. The design should fit the era and shape of the home, with the color being another option. Brick and stone are available in about any color imaginable. Therefore, homeowners have a great deal of diversity when selecting a color.

There is actually a fair degree of flexibility in choosing a style, but a couple of factors warrant consideration. The roof structure will determine how much weight it can safely hold. Selecting a material or size that is too large for the roof will eventually cause roof problems and leaks. This is another area where the expert advice of a professional contractor is highly recommended.

Calculating Chimney Size

As various designs are considered and the aesthetic appearance settled upon, the height of the roof is important. This is another situation, which requires the knowledge of chimneys and how they operate. The overall height from the fire pit to the actual opening where the combustibles are released into the air is critical.

Adding a cap that is too short, or too tall, can compromise the effectiveness of the chimney. It can even create a potentially dangerous heating problem. After calculating the overall height, the final dimensions and positioning of the top portion can be accurately determined. This usually does not alter the various style choices, but it will establish the size.

Chimney Design Ideas

A licensed professional will calculate the weight of the top portion. Picking the color and the shape is where the homeowner has an endless selection of choices for the best design. Here are a few style considerations that will provide some useful flexibility when settling on a final choice.

The style should blend perfectly with the house. Houses that are squarer benefit from a box shape and long, ranch-style homes, will find a rectangular design more appropriate. Once the structural soundness of the roof support system has been determined, the size can be as large as the roof will withstand.

The actual size is not what helps maintain proper air displacement and release of combustion. The final touch to both the visual aesthetics of a chimney and the function is the cap. Picking the right cap is like putting a cherry on top of a sundae.

There are hundreds of shapes and designs; each one can add that perfect final touch to a roof. The cap is also vital in how the heat remains inside the actual chimney to warm the home, while safely expelling the combustible materials. Selecting the right cap puts the finishing touches on a chimney.

Flashing a Chimney

If there is leaking in a roof around a chimney, it is very likely due to a problem with the flashing. A poor job of flashing can allow water to seep down along the structural walls and cause extensive damage. Here are some simple tips on how to flash.

Placing strips of flashing around the base where it meets the roof will prevent problems with a leaking roof around a chimney. When water and moisture seep down along the structural walls, it can cause shifting.

When any portion of the structure moves, it can create breaks that compromise the liner. The importance of the liner was previously discussed. Since flashing problems can damage the lining, it is critical that the flashing is installed correctly.

Homeowners can ask for a two-piece flashing system or a single piece. The color of the material can match the chimney color or the color of the roof. If the roof is metal, the knowledge of how to flash a chimney on a metal roof must be understood. Since metal roofs are made of long sections, if the flashing is incorrectly installed, then an entire segment of the metal roof may need to be replaced.

Bottom Line

Chimneys are like the crown of royalty. Picking the right top design depends on a number of factors. Consulting with a professional contractor that specializes in chimneys and roof repairs is highly recommended. When the right style is placed on top of a home, it’s like the cherry on top of a perfect sundae.

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