Introduction: Cinder Block (CMU) Offset Smoker
For a small fraction the price of a heavy steel smoker, you can setup a large capacity cinder block version. Not only will it be cheaper it will be better insulated. Follow the instructions attached for a very effective, efficient and not bad looking unit.
Step 1: Design & Dimension
Review design dimensions.
Step 2: Clear Area
- Clear appropriate sized area with offsets as needed.
- Soften and level dirt or ad layer of sand.
Step 3: Procure Cinder Blocks & Bricks
- Cinder Block: 8x8x16 (Qty. 60)
- Cinder Block (1/2): 8x8x8 (Qty. 15)
- Cinder Block (Caps): 8x2x16 (Qty. 16)
- Clay Brick: 4.5x9x1.75 (Qty. 24)
Step 4: Base Layers
- Place base layer of cinder blocks and use level to confirm flatness.
- Alternate seem on each level.
- Eliminate all air gaps.
Step 5: Complete Firebox
- Build firebox with rotated CMU bricks for air inlet and outlet as shown.
Step 6: Complete Chimney Structure
- With a chisel, break a 1/2 brick into half again so that the chimney has an opening as shown in picture.
- Stack chimney to 3 blocks high for appropriate air draw.
Step 7: Add Top Caps
- Place top caps on alternating seems from cinder blocks underneath. (Top caps will ad a flat surface for lids to seal better)
Step 8: Lid Construction
Lid Dimensions: 30.5" x 38" (Qty. 2)
- Cut plywood to dimensions.
- Procure Heat Shield Insulation (4 ft x 6 ft) and cut to same dimension as plywood.
- Using a staple gun, apply insulation to bottom side of wood.
- Fasten two lid pieces with hinges in middle and and handles.
Step 9: Add Clay Bricks
- Line the inner firebox with clay bricks for extra heat protection for the concrete blocks.
Step 10: Rebar Grate Support
- Measure off alignment for rebar supports. (3 places)
- Using a 1/2 inch concrete drill bit, drill holes through only one side of blocks.
- Insert 25" long, 3/8" rebar.
- Procure or cut, 3/4" X 13 ga. flattened expanded metal sheet to 22" x 53"
- Place expanded metal on top of rebar for a cook grate.
Step 11: Fire Box Lid
- Procure 29" x 31", 3/16" thick carbon steel plate.
- Drill and bolt in handles for easier removal (not shown)
3/16 steel plate is necessary for firebox as temperature here will be too extreme for thinner materials
Step 12: How to Use
Now you're ready to test it out!
- Use a left over block as a damper for your incoming fire vent. Slide back and forth to adjust heat.
- Leave stack vent open at all times.
- Add another expanded metal grate over the fire-pit if you would like the option to grill over the fire. (Good for tri-tip and chicken)
(This specific pit has about a 20 degree difference from one side to the other....which is actually very impressive.)