Building a firebox
The Rumsford fireplace was invented in the 18th century and was named by the man who invented it. This type of fireplace is a little shallower, smaller and a little more streamlined, thus preventing any smoke from entering your home.
First of all you will need to measure the area where you want the fireplace.
This is where the grate will go. The firebox needs to be strong as a wall. After you have constructed each line you need to cover the edges in concrete and then extend to the walls.
Fitting the Rumford throat
The firebox needs to be 2 to 2 1/2 feet tall. You need to mount the chimney throat on top of the bricks. Lay some mortar on top pf the bricks and then press the throat down until it’s flat on the bricks. Cover it with concrete and then cover it with a stone mantel in the place where it becomes thinner.
Building the chimney
Have the fireplace inspected by a professional. Once it is certified that it’s safe you can start building the chimney.Build the chimney until it reaches the roof and then you can cut a hole in it. All bricks need to be covered in concrete.
Add a stone veneer to the edges of the fireplace. The mantel is like the limit from where everything is being plastered. Test the fireplace only after the cement and mortar have dried. Make a small fire to see if the smoke is going up.