How does the acidity of rainwater affect marble outdoor bar stools over time?

Marble outdoor bar stools, while elegant and durable, are highly susceptible to damage from acidic rainwater over time. Rainwater naturally absorbs carbon dioxide from the atmosphere, forming weak carbonic acid. However, in polluted areas, rainwater can become even more acidic due to sulfur dioxide and nitrogen oxides, lowering its pH significantly.

When acidic rainwater comes into contact with marble—a calcium carbonate-based material—it triggers a chemical reaction that dissolves the surface. This leads to etching, loss of polish, and eventual structural weakening. Visible signs include dull spots, rough textures, and pitting. Frequent exposure accelerates deterioration, especially in humid climates.

To protect marble stools, apply sealants annually, clean with pH-neutral solutions, and consider covers during heavy rainfall. Understanding this process helps preserve their beauty and longevity.