Building Masonry Cookstoves

1

Determine the location, making sure there is no obstruction for the

stovepipe. The family must be involved with this decision. Level the

ground on which the stove will be built on. After being sick from

breathing too much smoke, I always insist that they move their

cooking fire outside while we are working inside.

2

Ideally members of the family will carry the materials and water, do

the mixing, sift the gravel, fill the bottom 2/3 of the stove, and even

cut and lay blocks if they have those skills. The more they are

involved with building the stove the better. Mix a large batch of 1 part

Portland to three parts sifted gravel and lay the first course of blocks

on a bed of mortar. Wet each block first.

3

Carefully lay the next course beginning sure that all joints are

overlapped.

4

Fill the center area with fill, ideally pumice but if not available, dirt.

5

Lay the top course of blocks leaving an opening in the front for the

door. Fill the block cavities with dry wood ashes.

6

Mortar in the door and lay the bricks for the walls of the firebox. The

top of the bricks should end up about 1½ inches higher than the

concrete blocks. Soak each brick first in salt water. Use a mix of 1

Portland, one lime, to two sand.

7

Lay the brick floor dry; wood ashes will fill any gaps between the

bricks.

8

Mortar in the door. With a couple of extra bricks and some wood or

folded paper shims, place a piece of board (which will later be

removed) to support the concrete over the doorway.

9

Set the Plancha (stovetop) in place on top of the brick walls. Then mix

up a batch of 1 Portland to 3 sifted gravel to pour the top. Be sure to

imbed four pieces of rebar over the door opening. The 3 sections of

stovepipe need to be installed at this time. The bottom pipe goes

through the concrete top, flanged at the bottom and supported by

bricks. A hole needs to be cut through the roof directly above.

Sometimes we have found that the roofing is not nailed down, if this

is the case then it needs to be now. Use a plumb bob to locate the hole

through the steel roof. I have found a leatherman tool extremely useful

for punching a hole through the steel roofing and making small holes

through the pipe for wiring the sombrero on. The sombrero (rain cap)

needs to be wired on. The concrete top needs to be worked to a

smooth finish. Central American masons will sprinkle pure Portland

onto the top, making a paste that they work smooth. They use their

bare hands, which are scarred from the caustic cement. If you value

your hands, use gloves.

10

With a mix of 1 lime to 2 fine sand, parge the outside walls. The

proper mix will stick to the block walls when buttered on with a steel

trowel. Use a wood float to obtain a smooth finish. This step and

obtaining a smooth finish on the top, takes considerable skill but only

with practice can you learn.

11

At this point you can congratulate yourself and the family members

whom have been helping. Their living conditions have been

dramatically improved. It is important that they know not to use the

new stove for two weeks to let the cement cure. It is helpful if they

keep the concrete top wet for the next two days by sprinkling it with

water whenever it looks dry. With a nail you can hang the lid lifter

close by.