How to Build a Fireplace Wall

Drop plumb line from ceiling near where you want the corners of fireplace wall to be. Doing this ensures you will have the right angle in relation to the ceiling. 

Place the first two layers, also known as courses, of stone at each corner. To make sure your wall stays plumb throughout construction, you can place a nail between courses and tie plumb line from the ceiling to the nail.

Begin laying courses of stone on either side of the opening. Using stones that vary in size and shape will give your wall a random, unplanned appearance. If you prefer a more uniform look, sort through stones to select stones of similar shape and size.

Place mortar between stones and between courses. Many traditional fireplace walls feature a thick layer of mortar between courses.

Use the rounded end of a broom handle to smooth and shape mortar between layers of stone.

Create a form made of plywood and lumber to support stones over the fireplace opening. To create a square opening, simply create a frame out of straight lumber. When creating an arched opening, cut a piece of plywood to the desired arch and attach to lumber support posts. Once you have completed the wall, remove frame.

Continue laying courses of stones until you reach the desired mantle height. This is typically 60 inches from the ground. For the top layer of stones before the mantle, try to select stones with a flat edge to be used as a support for the mantle.

Place mantle on top of stone fireplace wall. With a stone fireplace wall, you can use a wooden mantle or you can purchase slabs of stone. Use construction adhesive between top course of field stone and mantle for added stability. Use level to make sure your mantle is sitting properly on the field stones. If there are areas that are too low, you can find small stones and create a small course of stone to make the base for the mantle level.

Continue laying courses of stone on top of mantle until you reach the ceiling. For a decorative look, you may wish to lay stones out on the ground and create a design that will become an added focal point on your fireplace wall.

Caulk between stones and the wall behind fireplace wall. This will keep dirt and dust from accumulating behind them. Also caulk where the mantle meets the fireplace wall.