Capping Your Fireplace and Chimney

We all know chimneys are essential for your fireplace. But did you know that chimneys can also be the source of a lot of problems? The chimney is responsible for sending warm air from the firebox up into the chimney, which then exits out through vents in your roof. A chimney cap is installed on top and seals tightly to prevent any more leakage. Chimney caps make it easier to control how much heat goes up into your chimney as well as keep debris from getting inside- an often overlooked problem with other options like glass or metal caps. This article will help you understand what they do and how to put one on properly!

What Does Capping A Fireplace And Chimney Mean?

Capping your chimney means that you are putting a chimney cap on the chimney. A chimney cap is installed at the top of the chimney to keep drafts out and to prevent leaks from going up into the ducts. They are made of metal or glass and come in various shapes. They also have chimney extensions which help to keep the cap sealed tight against the chimney.

Chimneys should be capped when they are first installed, after any renovations that may impact airflows, such as adding a wood stove, making repairs to brickwork around the chimney base, or adding a chimney liner, new flashing, or chimney cap.

Capping your chimneys will help to avoid any potential fires from flying sparks out the chimney into your home.

Capping Your Fireplace: 

The fireplace is more prone to drafts and leaks because it has an opening in its front with a brick arch at the top. It is also closer to the chimney, and a chimney cap will help seal up that space between the chimney and fireplace.

The throat damper- an iron frame and door that opens and shuts the firebox- only slows down air leaks but doesn’t seal well enough for most chimneys installed today. A glass panel might work better, but it is also not ideal. A chimney cap will be installed on top of the chimney and spring-loaded, so there is a tight seal.

A chimney liner should always be added when you are capping your chimneys to help extend the life of an old chimney that might need some TLC.

What’s A Chimney Cap?

A chimney cap is an airtight enclosure that fits neatly on top of a chimney. Chimney caps are typically made from metal and have been in use for centuries to prevent rainwater from entering the chimney and causing water damage to your home’s ceiling below.

They also trap moss, leaves, or other debris that would otherwise fall into the chimney and then make their way into your fireplace’s firebox.

How To Cap Your Chimney And Fireplace

  1. Call a professional to assess the situation: Chimney caps are not installed by the homeowner. The chimney cap will need to be a custom fit for your chimney and fireplace in order to work correctly.

Caps can vary widely depending on the type of chimney they’re being used with, so it’s crucial that a professional assesses which one is best suited for your chimney.

  1. Purchase a cap that matches your home’s exterior design and color scheme: chimney caps are not just functional; they can also be aesthetically pleasing with a variety of chimney cap styles and colors to choose from.

The chimney will need to be inspected before the chimney cap is installed so that it matches precisely. Not all chimneys have the same dimensions- even if you had two homes next door to each other, chimneys could be different sizes.

Once the chimney is inspected and deemed safe for a chimney cap installation, it can be sealed with high-quality caulk or sealant to ensure that no air leaks out of the structure. 

The process only takes 30 minutes after all necessary measurements have been taken and an accurate fitting chimney cap is gotten.

  1. Clear out any debris from around the fireplace opening and chimney: Chimney caps are not difficult to install and usually only take a few hours, but they require the chimney to be cleaned out first. If there is creosote in the chimney or soot on the cap, it will compromise its ability to seal properly, which could lead to leaks and fires inside your home.

To clean out creosote, use chimney cleaner, chimney brush, and chimney rope. Creosote is a flammable material that can make chimneys emit smoke at an alarming rate. If not removed from the chimney, it could catch on fire which would be very dangerous for your home if there were any combustible materials nearby, such as furniture or other household items.

Creosote can also create chimney fires from chimneys that are not adequately maintained and cleaned regularly. If there is a chimney fire, smoke will be emitted at an alarming rate which could cause suffocation in the home if all of the windows are shut tightly. This would be especially dangerous for people with asthma or other respiratory conditions.

  1. Remove old mortar or sealant on brick, stone, or masonry surfaces with an appropriate solvent before applying new mortar or sealant: chimney caps must be applied to chimneys that are still in good condition. When installing a chimney cap, it is essential to measure for the correct size and verify that there are no cracks or gaps through which water can leak into your home and damage everything from wiring to drywall.
  2. Install the chimney cap per manufacturer instructions: Installing according to instruction is crucial. Chimney caps are made with chimneys in mind. The cap and chimney should be the same size or as close to it as possible, which means that a chimney must first be capped before being measured for a chimney cap.
  3. Check for proper clearance of combustibles such as furniture, curtains, rugs, etc., within 12 inches (30 cm) of any exposed edge of the cap and make adjustments if necessary; be sure to maintain clearances from heat sources such as fireplaces or stoves when installing caps over them. 

NOTE: Do not use chimney caps that are too small for the chimney. They will be ineffective and should not be used. Likewise, please do not place a cap over an open fireplace without first capping it off with bricks or something else to seal it shut. Don’t install chimney caps on top of ceilings because they can break loose and fall.

While we have laid out some of the processes involved in chimney and fireplace capping, an earlier point is worth repeating: 

The homeowner does not install chimney caps. The chimney cap will need to be a custom fit for your chimney and fireplace in order to work correctly. Caps can vary widely depending on the type of chimney they’re being used with, so a professional must assess which one is best suited for your chimney.

At A1 Home Insulation, our professionals install chimney and fireplace caps. We’ll carry out the necessary assessment to determine the best cap for your chimney. We also offer free evaluations and other services that will result in your home becoming energy-efficient.


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