Why You Should Not Use Bleach to Clean Your Deck

Why You Should Not Use Bleach to Clean Your Deck 

Deck cleaning

Many homeowners have used household bleach to clean their wood decks but cleaning a deck with household bleach is not an industry recommended best practice for a variety of reasons. This bulletin explains why bleach is not recommended and it provides suggestions for effective alternatives. Next week's bulletin will include a list of top-rated wood deck cleaners.

Why you should not use bleach

  • Household bleach (sodium hypochlorite) can potentially break down the lignin in wood causing excessive damage to wood cells. The natural pH of wood is slightly acidic, and bleach is a basic solution. As a result, use of bleach on wood shifts the pH from near neutral pH to a basic pH that will damage the cellular structure.
  • Bleach corrodes metal fasteners, screws, and nails.
  • Bleach can cause damage to surrounding plants.
  • Bleach, after several months, lightens wood's natural color.
  • Bleach does not eliminate the spores from which mold and mildew grow.

Alternatives to Bleach

power washing a wood deck

Hydrogen peroxide is environmentally friendly and a safer substitute than bleach. Its chemical formulation is H2O2. As the oxidizing process releases the excess molecule of oxygen, H2O (water) remains as its residue. For tough jobs, hydrogen peroxide kills the mildew on contact within several minutes.

Oxygen bleach is sodium percarbonate, an environmentally friendly and excellent detergent and bleaching agent with a hydrogen peroxide base. Sodium percarbonate is a cleaning and bleaching agent with a strong fungicide effect. It has been tested and found to be more effective attacking the deeper-rooted organic growth on the porous wood surfaces.

Sodium percarbonate is a white particle powder, nontoxic with no contamination, nonflammable, non-explosive, and soluble in water. It is also biodegradable and leaves no harmful by-products or residues that can harm the environment. Sodium percarbonate is effective in cleaning most average wood preparation jobs.

gray and cleaned deck

Apply oxalic acid (deck brightener) after using sodium percarbonate or hydrogen peroxide in the cleaning process. The deck brightener will restore the wood to its natural pH and neutralize the sodium percarbonate cleaner. Rinse well. This will provide a beautiful finish when applying the final stain. Deck brighteners are designed to neutralize and brighten wood without damaging wood fibers.

Next week we will provide you a compiled list of the 2022 top-rated cleaners that were tested or surveyed by nine sources.

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