What Is Mildew?

Mildew is a living organism, a fungus, which is normally observed as a black or dull gray deposit on exterior and interior surfaces. Mildew does not grow directly on a surface but on the accumulation of dust and other organic materials that settle on it. In addition to a food source, warmth, moisture, and a shady location all encourage the growth of mildew. The most common types of mildew are black or gray but some are green or even red in color.   Mildew is a surface problem that can occur on siding, shingles, decks, patios, roofing materials, stucco, driveways and even concrete. Normally it does not affect the strength or other important properties of exterior surfaces. It just looks bad.

How To Test For Mildew

Many times mildew looks like dirty spots and is hard to visually identify. An easy way to test to see if it is present is to dab a drop or two of a fresh bleach solution. We would recommend using an oxygen bleach solution (1 tsp. dissolved in a pint of hot water) or 3% hydrogen peroxide, but you can use chlorine bleach as well). Mildew will usually bleach out in a minute or two. Dark areas that do not bleach are probably dirt.

Other Common Exterior Stains

These can generally include tannins from leaves, algae, mold, animal and bird droppings, organic matter, food, grease and oil.

Traditional Methods For Removing Exterior Organic Stains vs. Using Oxygen Bleach based products like Deck and Patio Cleaner

Traditional methods many times involve the use of harsh toxic chemicals and acids like chlorine bleach, TSP (trisodium phosphate), lye or oxalic acid. Care must be taken not to spill these materials as they can harm you, your pets, plants, clothing or other sensitive materials. Pressure washers are also used because they are fast and can easily reach inaccessible areas like pitched roofs or second floors. However, they can also erode sensitive wood shingles, wood decks or other exterior surfaces. 

Deck and Patio Cleaner's main ingredient is sodium percarbonate, a solid form of hydrogen peroxide bonded with natural soda ash. It is activated by water where it releases oxygen which provides cleaning and stain removal. 
Deck and Patio Cleaner is the PROFESSIONAL STRENGTH oxygen bleach cleaner for those who care about the safety of their family and their planet. It is color safe, fabric safe, user safe, environmentally safe, and it is an excellent deodorizer. 
Deck and Patio Cleaner attacks and breaks down organic stains to totally remove them from the surface. 
Deck and Patio Cleaner is non-toxic, performs in hard or soft water, produces no harmful by-products upon decomposition and is compatible with other household cleaners (never mix chlorine bleach with any other cleaner).

How Much Deck and Patio Cleaner Should I Use?

A pound of Deck and Patio will clean 150 to 300 square feet of surface. Factors affecting coverage are temperature, substrate, surface porosity, degree and type of stain. For example: leaf tannin stains are normally very easy to clean but mildew imbedded into roofing shingles may require more than one application. 

Instructions for Use

Solution can remain “cleaning active” for up to 6 hours but will be most effective when used soon after mixing.

Avoid cleaning in excessive temperatures or in direct sunlight as the cleaning solution will dry out and not remain active.

Do not store in a sealed container as the “cleaning active” solution will give off oxygen and may cause the container to leak.
 

What Is The Best Way To Care For Exterior Surfaces?

 Though the best way to protect surfaces like decks, wood shingles, patio surfaces and roofing  is to remove the contaminants that cause the stains or encourage organism growth that is not always possible or practical. Another way to protect these surfaces is to use a paint, stain or sealer. Quality products that contain mildewcides, water repellants and ultra-violet protection provide the best performance.
 

What Exterior Protectant Do We Recommend? 

Natural Choices recommends NuKlear, the world's first water-based sealer/varnish. It is the only ambient-temperature, cross-linking acrylic on the market. It is a formulation of V.O.C. compliant acrylic resins that prevent the damaging effects of water, fungi and UV radiation on exterior surfaces. NuKlear includes a UV-blocker as well as a non-toxic fungicide to keep mildew, and mold from attacking.

NuKlear also contains a patented water soluble non-oil based water repellent which will give you years of protection over traditional products, guaranteed! 

Another advantage that NuKlear has is since it is a water based product you can apply it to a damp freshly cleaned surface.  That saves you time!! With solvent based sealers and protectants you must let the surface dry completely before application.

For additional information and to order NuKlear, visit the WonderPaint website.

Other exterior surfaces can be cleaned using the general procedure described previously.  Because of the porosity of some types of shingles (e.g. asphalt) and the fact that it is not always convenient to scrub the shingles, roofs can take longer to clean and may need more than one application especially if the roof is heavily stained with mildew or algae. 

Testimonials

While power washers can make it easier to clean inaccessible and/or pitched areas on roofs or decks care must be taken when using them.  Too high of a pressure can damage.  Also washers that blend water with the cleaning solution can dilute it too much to do any effective cleaning.  In general, using a pressure washer to rinse the roof after the cleaning solution has been applied and had a chance to work is the best situation.

How To Get Deck and Patio Cleaner

Can I Still Use Oxy-Boost To Clean Exterior Surfaces?

Oxy-Boost is a great product for cleaning any exterior surface.  It's versatility makes it the ideal environmeantally safe and non-toxic cleaner to use in and around the home.  Just use it as you would with Deck and Patio Cleaner (Add a little dish liquid to the Oxy-Boost cleaning solution to increase wetting of the deck.)  Check out the link below where Oxy-Boost was used successfully for  roof cleaning.

Reviews & Ratings For Natural Choices Oxy-Boost In Exterior Cleaning Applications

Oxy-Cling For Vertical Surfaces

Sometimes longer contact times are needed for cleaning vertical and pitched surfaces like railings, roofs , shingles and siding. Oxy-Cling is a safe acrylic thickener that is used with Deck and Patio Cleaner to make the cleaning solution thicker for better cling. 

Instructions For Oxy-Cling use:

For normal use add 1/4-1/3 cup or 2-3 ounces of Oxy-Cling per gallon of Deck and Patio Cleaner cleaning solution prepared as described previously.  Mix well before use to let viscosity develop completely. Apply thickened solution as necessary.

How To Purchase Oxy-Cling