Bio-growth (e.g., fungi, mold, lichens, etc.) on stone tablets and monuments stains and discolors surfaces, and can contribute to surface degradation. Cleaning off bio-growth, when appropriately executed, can effectively remove and nullify its negative effects and help the survey and recording process by making inscriptions more legible. Cleaning improves the appearance of a burying ground, making it look cared for and therefore valued, and is effective at deterring potential vandalism. Cleaning also further reveals conditions that may require repair, and is therefore recommended as a early step in the process of recording, assessing, restoring and protecting these vulnerable community resources.
The BGPG team provides a variety of techniques for the cleaning of tablets and monuments using only appropriate materials, tools and methods. BGPG also provides training and guidance in cleaning procedures to volunteers. Instruction and oversight is provided by a professional experienced in “best practices” to avoid irreversible damage to the stones. BGPG follows appropriate national standards of practice, including the use of effective and environmentally safe products.
This image (left) of the S. Foster Parsons (1839-1920) stone at the Hedges Parsons Burying Ground in Springs (Town of East Hampton, NY) shows the immediate affect of applying an anti-microbial solution and gently scrubbing the surface. The blackened surface remaining is not due to soiling; it is discoloration caused by living organisms including bacteria, fungi, algae, and lichens, rendering the inscription virtually illegible.
The purpose of this cleaning procedure is not only to improve the appearance and longevity of the stone, but to enable an accurate recording of the carved inscription. Removal of bio-growth is also made necessary in the context of stone repair.
This image (above) illustrates a typical brownstone tablet encrusted with lichens prior to cleaning.