Frequently Asked Questions

Every once in a while—it doesn’t happen often, maybe once or twice a year—we have a customer report that their planter box, shower bench, or other redwood furniture has stained their concrete or tile. The reason this happens has to do with the natural tannins in the redwood, via a process called “extractive bleeding.” It can happen with just about any wood, but is especially noticeable with cedar and redwood.

Redwood derives its durability and weather-resisting qualities from these naturally occurring chemicals, so in a sense, it’s a good sign! But unfortunately, the tannins can easily dissolve in water and cause the staining issue—and we have no way of predicting when it will happen.

The good news is, there is a solution (actually, a few):

• You can remove the staining with fresh lime juice,
• or with a diluted bleach solution,
• or with a mild solution of trisodium phosphate or other detergent and water.

If the stains are not removed and are permitted to oxidize, they can become darker in color. If that happens, you might need to remove them by scrubbing them with a soft (non-wire) brush in a 50% solution of alcohol and water. (If you are dealing with staining on grout, a slightly stronger bleach solution may be required.) It will take a few applications to fully take care of the problem. A couple weeks after the first application, the staining will likely return. You’ll have to remove it again and it will return a second time, but less so. Remove again and it may return a third time, but much less so… then it will be over, as the extractive bleeding has run its course.

If this happens to you, there is an easy solution!