DIY Fireplace With Bake Oven Plans

Select a relatively flat outdoor location with enough space to build an overhead shelter. Though not part of the oven plan, overhead cover will protect your fireplace/oven from rain and extend its life. Mark a 5-foot circle on the ground. Stack the stones or cinder blocks along the circle until they are waist-high to form the base wall. Use mortar or dry-stack the stones or blocks. You can cob over the dry-stacked stones later or leave them as they are as a decorative accent.

Fill the base wall with sand until it is level with the top of the base retaining wall. Level the sand. Cover the entire surface with tightly locked firebricks, and level them. Cover the firebrick shelf with damp newspaper, and tuck the newspaper edges into the interior side of the retaining wall.

Pile damp sand on top of the base. Form the sand to make a dome at least 2 feet high. The edges of the dome will reach the interior edge of the base-wall.

Spread the tarp on the ground and make the cob, using one bucket of clay mixed with one bucket of sand and a half-bucket of chopped straw. Add water slowly until the consistency is like sticky dough. Take off your shoes and walk on the mix, adding clay-sand until you can form shape-holding lumps the size of your hand. Repeat as necessary.

Cover the newspaper over the dome with cob, starting at the bottom and working up. Place the cob a handful at a time to create a lumpy surface about 4 inches thick. Leave a doorway in the front of the cob, approximately 60 percent of the height of the oven from the base. Make the doorway square-cornered or rounded.

Mix another batch of cob and double the straw. Repeat the process of adding it to the wall, this time for a second, lighter layer of 4 inches of cob, but lighter because of the extra straw. Press in this layer to fill the spaces in the first layer, and hand-smooth it on the outside. Let dry for three days.

Trace the opening for your door. Cut the trash can lid to an 8-inch diameter around the handle. Cut four equidistant Vs around the flange you made, leaving four flaps extending from the handle. Form a cob door on the tarp that fits the fireplace opening. Fold the flaps on the handle down approximately 45 degrees. Push the handle into the cob-door form just above center. Spread another layer of cob over the handle flanges, leaving the handle exposed. Let the door dry. When it is dry, place it in the doorway.

Dry the oven for four weeks, longer if the weather is very wet. Add a third coat of cob. Smooth it or decorate it as you like to form the final exterior surface of the oven. Let this layer dry for a week.

Remove the sand and newspaper from inside the oven. Some paper will stick to the cob interior. After the sand is out, build a small fire inside to burn off the rest of the paper. Keep a small fire going for several hours to finish drying the oven. After the fire burns out and the ashes cool, clean them out.