If left to weather naturally outdoors, redwood will change color over time. Fortunately, redwood color restoration is a fairly simple process, even for homeowners and do-it-yourselfers. If you are uncomfortable attempting redwood color restoration yourself, consider contacting trusted redwood contractors for help.
Elemental factors such as sunlight, humidity, rain and dirt all contribute to discoloration of redwood and other natural woods. Start the process of redwood color restoration by determining what is causing the discoloration. A few common causes are mildew, extractive bleeding and iron stains.
Identify mildew by applying a drop of household bleach to any dark spots you see on the redwood’s surface. If the spots disappear within two minutes, mildew is present on the wood. To remove it, simply scrub the surface with a mild detergent, and then rinse with household bleach. Finish by rinsing with water for effective redwood color restoration.
Severe mildew may be uniform, covering a large area of the redwood structure. In cases like this, mix a solution containing one cup of trisodium phosphate (TSP), one cup of household bleach and a gallon of water. Then scrub away at the mildew with a stiff bristle brush to achieve redwood color restoration.
Another cause of dark staining is extractive bleeding. Water soluble chemical extractives naturally occur within redwood. “Bleeding” occurs when these extractives reach the wood’s surface. Use oxalic acid for redwood color restoration in this case. Simply wash the redwood’s surface with a mixture containing one cup of TSP, one cup of household bleach and a gallon of water. Rinse well, then dissolve four ounces of oxalic acid crystals in a gallon of warm water and apply to the structure. Be sure to use non-metallic containers for both solutions. Allow the wood to dry completely, and then rinse with clean water.
When redwood is exposed to iron and water, naturally occurring tannins react and form dark stains. Any species of wood containing a high amount of tannin can stain in this way. For successful redwood color restoration, use the previously described treatment using oxalic acid solution.
For more information on options for finishing redwood, visit our Finishing Redwood page.