What Type Of Bleach Should You Use To Clean Old Cedar Siding

Wood surfaces

As wood ages, mildew (mold) and algae begin to abound on the surface. This is a normal process; these organisms do not dethrone the wood. They cannot break down the structural components of wood. They just live there. They feed off airborne contaminants, extractives, and oils in wood and in some finishes. Algae and molds can exist cleaned quite easily and effectively with bleaching agents such as sodium hypochlorite (liquid household bleach) and sodium percarbonate (the active ingredient in some commercial cleaners). Bleaching agents quickly kill mold and algae, but they likewise tin degrade wood. Therefore, mix cleaners as dilutely as possible. The object is to remove the fungi without excessive wood damage.

House_Stained-siding

The cedar siding on this firm has get stained. Photograph from Flickr: https://world wide web.flickr.com/photos/jahluka/

The authors of the study, Installation, Intendance, and Maintenance of Woods Shake and Shingle Siding, recommend using commercial cleaners containing sodium percarbonate or other oxygen bleaches because they are more gentle oxidizers than chlorine-containing bleaches such as household bleach. Chlorine bleaches tend to cause excessive pulping of the forest to give a fuzzy surface. However, some commercial cleaners contain potent alkali (sodium hydroxide or potassium hydroxide). These ingredients assist to remove residual finishes on the woods surface, but can cause even more surface harm than chlorine bleach. The photo below shows a person cleaning a deck with oxygen bleach and a gentle brush. These same techniques can be used to clean shingles and siding.

wash-deck

When using a cleaner, you might mix the solution weaker than the recommended forcefulness and endeavor it on a small area. If the weaker solution doesn't work, increase the concentration until you find a concentration that cleans the wood. A fuzzy surface appearance or excessive removal of surface fibers indicates that the solution concentration is as well strong. Utilise cleaning solutions with a garden-type sprayer, sponge mop, or soft bristle brush and go on the surface wet with the cleaning solution for 12 to 15 minutes. It is best to piece of work on a cool cloudy day or even during a gentle rain so the solution doesn't evaporate. Ambitious scrubbing shouldn't be necessary; let the cleaner do the work. Rinse with a garden hose keeping the h2o-stream pointed downwardly. High pressure shouldn't exist necessary. Y'all do not need a pressure washer! Allow the surface to dry out for several days before refinishing.

We recommended using commercial cleaners, but if you prefer to use liquid household bleach, start with a cleaning solution of about 5 parts warm water mixed with one part bleach) with a small corporeality of powdered detergent. Do not use detergent that contain due south ammonia. Ammonia reacts with bleach to form toxic fumes. If the surface mildew is difficult to remove, you should and then work with a stronger solution of iii or four parts h2o added to one part bleach and detergent. It should not be necessary to use a concentration stronger than three to 1.

If the dilute cleaning solutions described to a higher place are non constructive, it is probably because the mildew is inter-grown with remainder cease on the surface. The residuum end is keeping the cleaning solution away from the mildew. In this state of affairs, it may exist necessary to use more ambitious cleaning methods, such equally the cleaners containing potent alkali. In some cases, use a paint stripper to remove the remainder finish prior to cleaning.

Every bit with unfinished woods, wood finished with wood repellant preservatives (WRPs) and semitransparent stains degrades as these finishes dethrone. Ultraviolet radiation in sunlight degrades lignin at the surface. Lignin is the natural mucilage in wood that holds the cellulose fibers in place. Degradation of lignin weakens the surface fibers, and stiff cleaning solutions and ambitious methods will remove excessive amounts of cobweb from the surface. Removing these fibers is detrimental to the performance of subsequent application of WRPs or semitransparent stains. These finishes perform best by penetrating the wood surface and as a wood surface degrades, it becomes more porous. If excessive amounts of fiber are removed during cleaning, the surface volition not have these finishes as well as the porous weathered surface. Once again, when cleaning wood, the gentler the amend.

Fe reacts with the extractives in cedar redwood to requite a dark blue-blackness stain. This often occurs when the zinc on galvanized fasteners weathers away or from rust washed from other sources such equally window screens, failed flashing, or metal ornaments. This blue-black stain tin be neutralized with a v% solution of oxalic acrid (usually available at drugstores).

Note: Oxalic acid is toxic. Many commercial wood cleaners incorporate oxalic acid. Oxalic acrid will neutralize the iron stains and will too remove extractive stains. Oxalic acid generally brightens the wood surface, simply is not very effective for removing algae or mold, nor volition information technology keep iron stain from reoccurring if the source of the iron is not removed.