25/02/2026
Sometimes the outside of a church is just as interesting as the inside. These white stones are essentially stalactites or stalagmites! Their proper name is Tufa & it’s found in just a few places in the Weald along the spring line.
Tufa forms when groundwater deposits calcium carbonate. So, rain falls on the South Downs seeps through the chalk, dissolves carbonate, then re-emerges at the spring-line where it precipitates out of solution.
Look carefully and you’ll also spot oyster shells in the mortar. They were used because they’re rich in calcium carbonate (lime) — the key ingredient needed to make traditional lime mortar.