I was reading this Places Journal essay by the architect Jola Idowu about a kind of concrete made with shells called “tabby” when I came to this excursus on the word:
Over the course of about five centuries, knowledge of how to make concrete using oyster lime traveled from North Africa to Spain to Spanish Florida and then to the British colonies, a history that can be traced through the etymology of tabby. The word descends from the Spanish building material tapia, or rammed earth. When tapia was used in North Africa, it shrunk under the hot sun, compelling builders to develop a formula that could withstand drier weather. The North African tabbi added lime from shells and stone fragments to make a stronger, more resistant form of rammed earth, which the Almoravid and Almohad dynasties of the Moorish caliphate used for military construction from the 13th to 16th centuries. Later, the conquistadors who crossed the Atlantic to explore and colonize the West Indies brought tabbi to the Americas.
When Juan Ponce de León arrived in Puerto Rico as its first Spanish governor, he built his home with tabbi, then known in Spanish as tapia real. This is the oldest continuously inhabited residence in the Western hemisphere, and it was built with local stone mixed with shells and lime sourced from Cuba. But shipping was too expensive for large architectural projects; builders needed a local solution. So in 1580 the colonists began making tapia with oyster shells from nearby reefs. Tabique de hostion, or oyster concrete, was used for the old walls of San Juan and other construction projects on the neighboring island of Hispaniola. Soon this architectural knowledge spread to Spanish Florida, and up the coast to Georgia and the Carolinas.
But as far as I can tell, tabby, tapia, and tabique have separate origins. The OED says of the first that the ‘concrete’ sense “may be a different word, though it may also have originated in a fancied resemblance of colour to that of the tabby cat,” which “is generally held to have been so named from the striped or streaked colour of its coat” after the “general term for a silk taffeta, apparently originally striped,” itself from “French tabis, earlier atabis […], Spanish tabi, Portuguese tabi, Italian tabi, medieval Latin attābi […], apparently < Arabic ʿattābiy, name of a quarter of Baghdad in which this fabric was manufactured, named after ʿAttāb, great-grandson of Omeyya.” Now, the OED entry is from 1910, but Wiktionary agrees; it says Spanish tapia ‘wall; wall made of adobe bricks’ is probably of Germanic origin, from Proto-Germanic *tappô ‘tap, plug,’ and tabique is from Arabic تَشْبِيك (tašbīk). Anybody know anything about this tangle?
Hm. The U.S. National Park Service says the current Taos Pueblo buildingshave probably were probably built around 1400. They’re residences, and from what I can tell, there’s no reason to doubt they’ve been inhabited continuously, though they’ve been modified a lot over the centuries.
The DRAE says tapia is “de or[igen] inc[ierto]”. It has both the “wall” and “rammed earth” meanings, but defines “tapia real” only as a wall of earth mixed with lime.
I am not a conchologist or a materials scientist, but I am initially surprised by the notions that the shells readily available in Cuba were so different from those readily available in Puerto Rico, for purposes of usefulness in mixing into concrete, that the Spanish imported from from the former island to the latter for some considerable time before adapting to local supply.
In the old times, oyster shells for lime would have come from the old middens rather than directly from the sea. The population of Puerto Rico might not have left shell middens big enough for the huge colonial construction projects, though.