How to install a cast iron fireplace in your home
Create a warm and cozy ambiance on those cold winter days and nights with your closed combustion; cast iron fireplace. Wood-burning stoves made of cast iron retain heat better than other stoves.
It is always good to check the build quality of a cast iron fireplace, how sturdy it is and the type of materials used that make up the fireplace. They come in different shapes and sizes. You will have to decide between a multi-fuel fireplace or a fireplace suitable only for burning wood.
Flue piping is an essential part of any cast iron fireplace, buy only the best stainless steel or mild steel flue pipes. Flue pipes get extremely hot as they are installed and connected directly onto the cast iron fireplace and need to be able to withstand high temperatures. Stainless steel flue pipes will sometimes discolor to different blues, yellows, and reds due to these high temperatures.
It is crucial to use insulated stainless steel pipes wherever the flue pipes come in contact with outside elements such as cold temperatures, wind, and rain or flammable materials such as ceiling boards and wooden trusses inside the roof cavity.
Insulated pipes ensure that the smoke in the flue pipe stays hot and exits properly without cooling down and pushing down into the flue pipe. With that said the flue pipe outside needs to be above the natural reflux zone (internal link to reflux zone article) to ensure that there is a proper draw on the smoke coming from the cast iron fireplace.
How to install a cast iron fireplace
- Power tools: Grinder, jigsaw, and a drill
- Screwdrivers and Allen key set
- Measuring tape
- Silicone sealant
- Waterproofing materials
- Cast iron stove
- Flue pipes and components
1: Position the cast iron fireplace
Decide on where you want the cast iron fireplace to be within your room ideally; this will be in the middle of the room away from flammable materials such as curtains and furniture. Ensure that there is a safe distance of between 750mm – 1000mm between the cast iron fireplace and any combustible materials. Furthermore, the fireplace should be at least 150mm – 250mm away from the wall to prevent plaster cracks.
2: Mark the ceiling exit point
Measure out & determine where the flue pipe will exit through the ceiling. It is vital to ensure that there is no wooden truss beam in the way of the flue pipe. It is best to check inside the roof before cutting through the ceiling board in the first place. If there is no wooden truss obstruction, mark the ceiling exit point by drilling a small pilot hole.
3: Cut the ceiling and open the roof tiles
Use the pilot hole as a guide and draw a circle slightly bigger than the flue pipe diameter on the ceiling to cut out. For example, if your flue pipe diameter is 150mm then draw a circle of 155mm. Cut the ceiling board using a jigsaw. Don’t worry that the hole is bigger than the flue pipe diameter; this will be covered later with an escutcheon plate. Remove the roof tiles directly above the hole in the ceiling to make space for the flue pipe to exit the roof towards the outside.
4: Connect the flue pipes together
Start with connecting the single skin flue pipes. Most flue pipes fit into each other some come with clamps to connect them to each other and ensure a proper seal with others requiring pop rivets to install them together. Remember to put the escutcheon plate around the flue pipes before feeding the flue pipes into the roof cavity. Use insulated pipes before the ceiling, inside the roof cavity and outside to keep smoke from cooling down.
5: Cut the roof tiles and seal-off the roof
Cut the roof tiles using a grinder and replace the tiles around the insulated flue pipe going out. Silicone and waterproof the flue pipe exit point on the roof using a flashing and some waterproof membrane.
6: Install the cowl and test the cast iron fireplace
Lastly, install the cowl on top of the insulated flue pipes and check the cast iron fireplace by lighting a small fire to test the draw of the smoke. Remember to burn in the cast iron fireplace and let the different metal components settle. Have a look at our burning-in your cast iron fireplace guide for further details.
View our full range of freestanding cast iron fireplaces here: https://www.multifire.co.za/collections/freestanding-fireplaces/design_cast-iron