But you you should never block at both the top and the bottom. Why? You need air to be able to get inside the chimney and breathe as the temperature will still rise and fall inside as the house warms up and cools down. This is very important otherwise you may get dampness coming through your walls over time.
You could just board it up with plasterboard/plywood - either above the fireplace itself, or in front of the fireplace to block the whole area off. Decorate as desired.
I have found the best way to seal an unused fireplace flue is to install a piece of slate or thin stone on top of the unused flue tile using masonry caulk to adhere the stone. This way, if the fireplace is ever to be used in the future, the piece of stone can be removed easily without causing any damage to the flue.
In most cases, the easy answer is just to cover the opening up. You can have the opening permanently blocked off with painted brick (for example) and then have that chimney capped. Or, temporarily put in an electric insert or something safe.
Close Off Fireplaces with a Throat Damper
“If you have a bottom/standard masonry damper you can close it and seal it closed with silicone to stop the airflow,” says Blaken. The damper itself goes a long way toward closing off the fireplace, which is why every wood-burning fireplace needs one.
"The estimated cost to remove a decorative fireplace and prepare the wall for mounting a TV, can range from a minimum of £350 to £700 for a basic removal with minimal wall repairs to a maximum of £3,500 to £7,000 or more for a more complex project, which may involve structural modifications, high-end wall finishes, ...
Closing the damper on your fireplace should be very easy. If you have a throat damper, you can close it using the lever above the firebox. Some chimneys have top-mount dampers, which close using a chain. If you have a gas fireplace, make sure to turn off the pilot light as well.
If you have an unused chimney in your home, it's important to consider capping it off to prevent heat loss and moisture build-up. Not only can these issues be costly to fix down the line, but they can also pose safety concerns.
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.
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.
Even when your fireplace isn't in use, it may cost you. Leaks in the fireplace door (if present), vents and fans, and the chimney can allow heated air to escape in the winter and let hot air into your home during the summer months. That's where insulating your fireplace pays off!
Baby gates are the simplest and most obvious way to babyproof a fireplace, so let's take a moment to discuss the many types of baby gates and how best to utilize them. A high-quality gate alone can safely restrict most fires, so investing in a quality product is worthwhile.
Is Venting an Unused Chimney Important? Even when you have retired your masonry fireplace from use, yes, venting an unused chimney is important. It is vital to allow for continued airflow, and that's not the only issue.
While drywall is fire resistant and used in fire-rated wall and floor/ceiling assemblies, it is not rated for use in fireplace insert surrounds. Radiant heat from pellet or gas inserts dries the cover paper, which is combustible and can pose a fire hazard.
You could go for an inflatable draught excluder, which will fit snugly inside your chimney. Just make sure that it has a small vent, so air can pass through.
Yes, chimneys need to breathe, even if they won't be used anymore. The vast majority of problems with chimneys are related to moisture, and that's the issue as regards ventilation. If there is no air flow in the chimney, moisture gets trapped and deterioration of the chimney structure will be accelerated.
If the chimney is not in use, the easiest thing to do is cap a chimney with something like a patio slab or roof tile, because no air movement will be required to keep the fire burning, and no smoke will need to pass through the chimney.
You could remove the fireplace and block up the opening with bricks and plaster. This could be made airtight or instead it could be done but with an air vent installed where the chimney opening is situated. This is a good option if you want to create more space in the room by removing the fireplace completely.
Choosing to block a fireplace
Taking out a fireplace doesn't just mean knocking out a few bricks and boarding it up. Blocking up a fireplace can add extra space to a room and even improve the heat efficiency of your home. This is because the fireplace is an easy area for heat to escape.
Permanent Solutions might involve sealing the chimney flue and potentially repurposing the fireplace space for aesthetic or storage purposes. It could mean more extensive modifications, such as installing an electric fireplace insert or completely sealing and insulating the chimney breast.
Choosing the Right Block for Your Fireplace
Concrete blocks are superior in handling heat, crucial for fireplace safety. If you need a robust and long-lasting fireplace, concrete blocks are the way to go. Cinder blocks provide better insulation, helping keep rooms warmer with less fuel consumption.
Yes, capping an unused chimney is important to prevent moisture buildup, downdraughts and animal intrusion which can cause damage over time.
The average cost to remove a wood-burning fireplace or stove is $500 to $1,000, for demolition labor, debris disposal, chimney capping, and patching the walls, ceiling, and roof. Extra costs may apply for removing or covering the ventilation system.