General Cleaning / Warm Weather Notes
To gently clean superficial dirt, unwanted mold or moss off carved stone, cast stone or marble ornaments, fill a spray bottle with one part ammonia to two parts water. Spray the solution on the affected areas and allow it to soak in for several minutes. Rinse with water (spray with hose) and repeat several times. For stubborn stains, we recommend using a non-abrasive cleanser (such as Softscrub without bleach or mild baby shampoo) and a soft-bristle brush. Any cleaning beyond the most superficial should be done by a trained conservator.
In warm weather, marble ornaments are susceptible to damage caused by high humidity and acid rain. A condition called sugaring can result in a deterioration of the surface. Watch for a sandy surface on marble and take prompt action by contacting a professional conservator. Do not ever leave a cast-iron urn on a marble or stone bench. The stain that results is guaranteed to keep you awake at night!
When leaves drop in the autumn, try to keep them from sitting too long on your outdoor pieces, as they can leave stains that are hard to clean later. A quick sweep with a broom can save you time and trouble.