Building a Rumsford Fireplace
The Rumford fireplace is created to an exact design, developed in the late 18th century and named after the man who invented them. Rumford fireplaces are typically shallower, smaller and more streamlined, so that they prevent smoke from traveling into the house. The design of the Rumford fireplace helps to keep the fire burning pleasantly for everyone. In the modern era, fireplaces have become more popular, and the Rumford fireplace has regained its importance in efficient heating. For those wishing to create a Rumford fireplace, there are a few steps that you can follow to get the best out of your built fireplace.
Step 1 - Measuring the Dimensions
The first thing that needs to be measured is the area in which you intend to build your fireplace. You will need to keep your measurements in proportion, as the chimney must be around 5 or 6 inches smaller than the firebox. You can order chimney parts, and then build the firebox and fireplace around them. If, for example, your chimney flue is 24 inches, then you should have a firebox which is 30 inches across.
Step 2 - Build the Firebox
The firebox, the area where your grate will go, is possibly the most important component of your tools, and you should construct it as though you were building a wall. As you complete the end of each firebox line, you should cover the edges in concrete,and extend this to the surrounding wall, so that you are essentially bricking the fireplace in with each line.
Step 3 - Fit the Rumford Throat
Once the box is the right height, around 2 to 2 1/2 feet tall, mount the Rumford chimney throat on top of the bricks. You should lay a line of mortar, and press the firebox down until it is completely flat on top of the bricks. Cover the throat with concrete, and them place a stone mantel at the point where the throat becomes significantly thinner. You now have the basis for your fireplace and surround.
Step 4 - Build the Chimney
At this point you will need to have the fireplace inspected by a buildings regulator, and certified to ensure that it is safe. Once this is confirmed, you can continue installing the chimney pieces until the roof is reached, at which point you can cut a hole, and pass the flue out into the top of the house. Place the rest of the bricks up to make a traditional chimney flue, and then surround them all in concrete. Once you have the chimney built, you can return to considering the fireplace.
Step 5 - Finish the Fireplace
You can now add a stone veneer to the edges of your fireplace, making sure that everything complies with building regulations. The mantel should act as a cut-off point for the fireplace, with everything above that being plastered and treated much as the walls in the rest of the house. Once all of your mortar and cement is dry, test out your fireplace using a small portable barbecue, to check that smoke travels up the chimney as Rumford intended.