Remove Tannin Stains From Concrete. 22092017 Cleaning light tannin leaf stains from concrete or brick can be done with a strong household detergent made to remove organic staining. If the stain is still there then you may need o leave the acid a bit longer.
20072012 Dont be put off by reading the words wood bleach because the materials with the tannin stains are sandstone the ingredients thats required to react with the tannin is oxalic acid which is an ingredient found in the wood bleach. Both happened to have those pesky tannin stains which were from leaves and acorns. How to Remove Tannin Stains on Concrete Step 1.
15112019 If the stain is bothering you you probably dont want to wait for Mother Nature to take care of it because this may take some time.
2042009 Power-wash the concrete to get rid or surface dirt and mold. Follow manufacturer instructions for oxalic acid or apply hydrochloric acid and leave for a couple of minutes then wash down with plenty of water. 6012016 Tannin stains on outdoor concrete often go away on their own thanks to the powerful bleaching action of the sun. Scrub the stains again.