Closing off the top of a chimney can have serious consequences. It renders the fireplace unusable, as combustion requires airflow to remove dangerous gases and smoke. A blocked chimney can cause these gases to back up into the room, leading to a dangerous situation due to the accumulation of smoke and heat.
As one of the biggest causes of a draughty home, it can make sense to block a chimney opening, especially for larger unused fireplaces. Fixing a draughty chimney not only makes your home more comfortable, it helps to lower energy costs too.
No, you need to keep the chimney ventilated allowing free flow of air through the flue(s) and out the top, otherwise you risk damp causing problems in the house and loft. There are many ``related threads'' in the section below.
In addition, the home's interior could be affected by moisture damage. A retired chimney should be sealed only at the top or bottom. This will allow air to pass through the chimney and help prevent problems caused by moisture. If your damper is near the firebox, you can use insulation to seal the chimney.
You can block the top of your chimney using a flue ventilator or chimney cap with mesh, leaving space for chimney ventilation. Read more to find out how to cap your unused chimney and the benefits!
Ventilation is necessary for unused chimneys because, otherwise, moisture will become trapped inside the structure. Moisture together with poor ventilation creates ideal conditions for mold growth. Mold easily goes undetected and yet it can quickly spread throughout a home.
The cost of capping off an unused chimney depends on the size and type of the chimney. The most common type is a masonry chimney, which ranges in price from $500 to $1,200. If you have a metal chimney, the cost will be about $200 to $400.
Chimney Sealing
Sealing a chimney costs between $150 and $500. This is also known as chimney waterproofing. During this process, cracks are sealed with mortar, and a waterproofing agent is sprayed onto the chimney to protect it against water damage.
You should cap any unused chimneys with a flue ventilator. Flue ventilators can be found on our chimney pot page. The flue ventilator stops rain entry to the chimney but still allows a small amount of air passage for ventilation.
In fact, chimneys are designed to draw air out and expel it outside. This is so, when you light a fire, the smoke can be carried outside rather than blown into your home. However, when a fire isn't lit, warm air that's created by your heating system can be lost via the chimney.
An unused chimney should always be swept and given a little ventilation top and bottom. Ask your Guild sweep how best to do this for your situation.
A cowl can be used to cap off the chimney, which will allow air to flow in and prevent any moisture from building up. This costs roughly £150. If you want to remove the chimney breast (the part of the chimney in the room) and have the space made up, this can cost between £1,750 - £3,250.
If you are absolutely sure the chimney is no longer used by any of the home's fuel-burning appliances, then, yes, by all means, take the chimney down below the roof. Anything that projects through the roof is a source for a leak just waiting to happen.
In fact, you can lose 10 to 20 percent of the warm air from your home through your chimney's damper. Suddenly, your fireplace is increasing, rather than decreasing, your home's heating bills!
If your chimney is blocked up and is capped and sealed at the top, the lack of ventilation could be causing chimney condensation to build up in the void, meaning that when your house warms up, condensation collects and forms damp on the chimney breast surface.
An uncapped chimney can lead to moisture building up, which can cause damage to your chimney's interior and exterior. This can result in costly repairs or even replacement. Protecting your roof from burning embers is also another crucial factor why capping a chimney is necessary.
Just because a chimney was designed to breathe doesn't mean it has to breathe, and I have blocked off all of my unused chimneys without any issues. If you insist on letting it breathe then let it breathe using outside (unheated) air only.
Do I need a vent in a blocked-up chimney breast? The simple answer is yes. A blocked-up, unused chimney breast should be vented at both the top and the bottom.
Homeowners insurance is one of the most important types of property insurance. It includes coverage for many different types of damage to your home and its contents, including leaks in your chimney. It's also mandatory to have if you're trying to get a mortgage on a home.
Properly closing up a chimney involves closing and sealing the damper, installing a chimney cap damper, and sealing the fireplace opening with a door or bricks. The cost to seal and cap a chimney is around $500 to $650—significantly less than the average chimney removal cost.
Chimney caps are most commonly installed by two kinds of professionals: chimney sweeps and roofers. Both groups are familiar with the safety procedures involved with working on roofs, and they're typically well-versed in chimney cap sizes and styles to help you find what you need.
Close the damper when the fire is extinguished. This will prevent the heated air from escaping through the chimney and will keep water and other debris out of the flue.
The space above a fireplace mantel is too high for comfortable TV viewing. The center of the screen should be at eye level when you are sitting and facing the screen. Unless your fireplace is unusually low, its height will likely conflict with the optimal viewing height and angle for the TV.
Our disused chimney cap cowl (aluminium) is designed to cap off unused chimneys and prevent rain, birds, leaves, and vermin from getting into the chimney stack. This chimney cowl is made from aluminium which is beneficial as it is a corrosive-resistant material.