Fireplaces on multiple levels can also share one chimney structure. Since the fireplaces are on different stories of the home, the chimney extends from the lowest floor through the roof. Each fireplace can face the same direction, if you want, since they will not block each other.
Upstairs Fireplaces
In most cases these fireplaces share one chimney, but use their own separate flue to exhaust smoke and byproducts. This type of setup is totally normal and nothing to be alarmed about, however, there are some unique issues that can arise for homeowners with fireplaces on two floors.
This rule means that your chimney's shortest side needs to be at least 3 feet above the roof penetration, and its top has to be 2 feet higher than any part of the building that's within 10 feet.
Each fireplace will have its own flue within the chimney structure. Although the fireplace may seem to be directly in line with the flue, the lower floor flues will bend to avoid the fireplaces on the floor above and will run side by side.
Each fireplace should have its own flue right up to the chimney pot. On the upper floors the flues will normally be contained in the chimney breast to the left and/or right of the fireplace on that floor. The flues will curve as they go up to avoid the fireplace on the next floor up.
Many older homes have fireplaces on separate floors. This was common before central heating came along, and the fireplaces were an important part of heating the home. More often than not, these fireplaces come with separate flue and chimney systems. That way, the smoke from each fireplace stays separate.
In older houses located in colder climates, it was fairly common to have one chimney with two or more separate flues. This would allow a homeowner to vent, say, an oil-burning appliance as well as one, two, or even three wood-burning stoves/fireplaces. “Older” is the keyword here: these houses were not airtight.
Multi-Level Fireplaces
Fireplaces on multiple levels can also share one chimney structure. Since the fireplaces are on different stories of the home, the chimney extends from the lowest floor through the roof. Each fireplace can face the same direction, if you want, since they will not block each other.
Many chimneys are built on party walls, and it's commonplace for chimney stacks to be shared. Many party wall chimneys tend to be 'back to back' – in other words, the way it was originally constructed on your neighbour's side will be the same as on your side. They will normally be a 'mirror image' of each other.
(c) An existing chimney may only be utilized with one or multiple gas appliances if the interior area of the chimney is no greater than seven times the area of the smallest flue to be connected to that chimney. burning appliances is used with an appliance using fuel gas, an accessible cleanout shall be provided.
This is a pretty basic rule for chimney construction. A chimney must project at least 3 feet above the roof on its shortest side and also be at least 2 feet above any roof structure that is within a 10 foot radius of the chimney. That's it.
Non-heating home systems also use chimneys as a way of venting gasses. These include water heaters and wood cooking stoves. While many of us haven't likely seen a wood cooking stove for many years, older homes having a second chimney near the kitchen would have been commonplace.
> Chimney - this is the structure which connects your fireplace to the outside world. A chimney contains a flue (some chimneys will contain more than one flue). > Flue - this is the space or cavity within the chimney which allows the smoke and gases from your fire to pass up, away from the fire, and out of your home.
In semi-detached or terraced houses, the chimney stack is often shared between two or more properties. It forms part of the roof structure, providing a vent for fireplaces, boilers, or stoves.
Electric Fireplaces Don't Need to be Vented
The reason that fuel burning fireplaces, such as wood and gas, require vents, is to expel excess heat and dangerous emissions, such as carbon monoxide. Because electric fireplaces do not burn fuel internally or produce any emissions, venting is not required.
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.
Chimney Balloons can deflate over time and can be prone to puncturing. Re-inflating them every three months can become tiresome and even messy. Unless you don't mind getting in your hands and knees to re-inflate or re-install your balloon every 12 weeks, we recommend that you get a Chimney Draught Stopper.
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.
Although a chimney appears to 'suck', and smoke appears to naturally rise, it is more accurate to think of the weight of dense outside air pushing down to force air into the building and so push the hotter, lighter, waste gases out up the stack, somewhat like an air bubble rises in water.
A flue is a venting system, each system needs its own so If you heat your home with oil or gas and have a fireplace you would have two flues. Often times they are in one chimney so if you were to look down the chimney it would be separated into two venting system inside one chimney.
Yes, two fireplaces can share a chimney, but it's not a decision to be taken lightly. The design and construction must be meticulously planned and executed according to local building codes and safety standards.
3-2-10 Rule Explained
This rule refers to the proper height of the chimney pipe above the roof. Explained, the chimney pipe must be a minimum of three feet above the roof but also two feet taller than anything within ten feet.
A shared chimney stack is commonly found in terraced or semi-detached homes. Often they qualify as party structures under the Party Wall etc. Act 1996. As such they are often jointly owned by the owners on either side of the boundary, and certain works require notification under the Act.
It provides increased ventilation and improved air circulation within the building. With two chimneys, there is a better distribution of smoke and odors, reducing the chances of any lingering smells.