Strong Walls From Refuse

Settlers on St. Simon’s Island in the 1700s used oyster shells as an unusual building material, drawing on piles left from long-ago feasts of the local Guale and Mocama Indians. These shell mounds, or middens, provided the basic ingredient for tabby, a crude but durable concrete. To make it, stacked logs and oyster shells called ricks were set afire and burned down to hot embers, turning the shells to ash; the wood and ash mixture formed lime, which when mixed with water, sand, and more oyster shells acted as a binding agent that solidified the mixture. It was then poured into molds for foundations and walls and stuccoed and whitewashed to protect against water damage. The settlers borrowed the recipe from the Spanish, and the word may come from the Arabic tabbi, meaning a mixture of mortar and lime, or the Spanish tapia, meaning a mud wall. This very old building material dates to the 1500s, and many of Frederica’s strong walls and foundations were built of tabby.

Georgia · United States