What are tannins?

Tannins are chemicals produced by plants to help protect them against insect attack. Tannins can appear as brown stains on the wood and, being mostly water soluble, can be washed from timber by the rain, staining pavers and other surfaces. Tannin stains are often mistaken for a timber coating that has been washed off by the rain. Reviva can be used to remove tannins from some types of pavers. We recommended testing Reviva on the surface of pavers first in a small, inconspicuous area before applying on a larger scale.