The Lexington Collection
Pretty Polly
    A Backyard Barbecue Machine
Design Considerations
Besides being extremely large, the pits at classical barbecue joints all seem to have several features in common. Wood coals are the heat source. The meat is cooked directly above the wood coals in the pits. The pits themselves are massive masonry structures. And, a separate hearth is present for burning the wood down to coals. These observations became the basis for the design of Dave's "Wilber D. Hog" Barbecue Pit.

    Commercial Pits 

The pits in eastern North Carolina are rather simple structures. A brick or block foundation supports racks for holding whole hogs about 18 inches above the floor. A lid, usually of roofing tin, covers the top. Coals are added through doors at the base of the foundations. These closed pit designs, simple and effective, require a great deal of attention when making barbecue to maintain a uniform temperature over long periods of time. The western pits, usually of brick, are basically a fireplace with doors and a rack perhaps 18 to 24 inches inches above the floor. Coals coals are added through an access door at the base of the pit. Another door above that provides access to the rack. And, although new coals must still be added regularly, the large thermal mass of the pit walls help moderate the pit temperature. This lead to the decision to design "Wilber" in the western North Carolina style.

    Design Drawings 

So just how large should this pit be? Cast iron doors were found that have openings 16 inches wide and 12 inches high. Standard bricks finish out in multiples of 4 and 8 inches when laid. Careful measurements suggested a rack surface that was 16 inches wide and 24 inches deep would accomodate a very large turkey or a brace of barbecue shoulders. With front and rear walls two brick-widths (8 inches) thick, that mades the pit a total of five brick-lengths (40 inches) deep. With a coal hearth the same width as the grill (16 inches), a wall two brick-widths (8 inches) thick between pit and hearth, and the two side walls, the overall width of the pit comes to a total of seven brick-lengths (56 inches). With accomodations for a firebrick floor and a roof two bricks thick, the height of the pit reaches upwards of 18 courses (48 inches). And, with two chimneys built around 8-inch flue pipes, the material requirements quickly approach 800 bricks, not including the fire bricks for the floors. Now, that's a pile of bricks!

The whole thing is supported by a hefty concrete foundation, and the design is finished off with a quarry tile top and twin chimneys constructed with (8 inch) tile flues and some sort of chimney caps.


The Wilber Collection