This post was updated on April 11, 2023
RAD Guard Mildew and Algae Cleaner and Preventer
We would love to hear from you if you have used the RAD Guard to clean or prevent mildew on your wood or deck. Please post a rating in the Consumer Star Ratings below.
If you have any questions about using the RAD Guard, please ask in the comments below.
RAD Guard Mildew Cleaner & Preventer Product Info
RAD Guard RTU (Ready-To-Use formula) is a no-rinse cleaner and preventative that is safe and effective for removing and preventing stains caused by mold, mildew, and algae on exterior surfaces and exterior wood or deck stain coatings. RAD Guard cleans without pressure washing, scrubbing, or rinsing. Contains no bleach, chlorine, acid, sodium hydroxide, or phosphates.
Pro Tip: Can Be Applied Over Existing Paints, Stains & Sealers
RAD Guard Prevents Mildew For Exterior Wood and Decks
Keeps cleaning long after application, keeping your wood stains looking better longer. 1-2 years of mildew and algae prevention.
Pro Tip: RAD Guard RTU is not used for prepping wood for wood or deck stain application. The primary goal is to remove mildew or algae stains and prevent mildew and algae stains from returning.
RAD Guard Review Scores (1-10)
RAD Guard Removal of Mildew and Algae: 10
– The RAD Guard was applied to a bench that was covered in mildew and alage. Both the algae and mildew disappeared from the bench after about 2 weeks.
Pro Tip: It takes time for the RAD Guard to work. The key is patience and it can take 1-3 weeks for stains and mildew/algae to disappear. The cleaning time varies based on the amount of rain after applying and the severity and the type of stain being removed.
RAD Guard Cost Per Square Foot: 8
– The RAD Guard covers 200 sq. Feet per gallon for $50. We used less than 1/10th to test this bench.
Note: The RAD Guard also comes in a concentrated formula that will clean and prevent mildew for up to 1000 sq feet.
RAD Guard Ease of Application: 10
– Very easy. Use a pump sprayer to apply on top of your wood or a fully dry wood stain and let it work.
RAD Final Appearance after 2-3 Weeks: 10
– Very clean throughout the application area when done. It fully removed the mildew and algae.
Overall Score for RAD Guard: 9.5
– This is a great product to keep your deck looking good in between a full prep and recoating. It will remove and prevent mildew that can grow on top of your exterior wood or deck stains, making your deck look better.
RAD Guard Product Info
Manufacturer: Restore-A-Deck
Product Type: Mildew and Algae Cleaner and Preventer
Available Sizes: 1-Gallon
Application Temperature: 45-95 F
Coverage Per Container: 200 sq. ft per Gallon
Application Tools: Pump Sprayer
Test Deck Stats:
Deck Wood Type: Pine Bench
The Condition of Deck: Black Mildew and Green Algae Spots
*All products tested and results are from our experience. We offer no guarantee of similar results. Take into consideration that results may differ due to different wood types, exposure to UV radiation, and natural weathering.

As an article and comment contributor to the site, Scott has been around the pressure washing industry since attending college. In 1993 he started his first company called Oakland Pressure Wash specializing in exterior pressure washing and deck staining. That company evolved into OPW L.L.C. shortly thereafter concentrating more on exterior wood and deck restoration. Scott and his Deck Cleaning Michigan company have restored over 10,000 decks in the Metro Detroit area since the early years. He has become an authority in the deck restoration industry and has contributed to numerous wood restoration forums and informative sites.
All the products he suggests through this site are sold through online sites and in retail stores, allowing the consumer to choose their own means of purchase. Scott’s eCommerce sites do sell many top brands he endorses and if you appreciate any of the help he has offered then feel free to purchase from one of them.
How long until pets can walk / lie on the deck after application?
As soon as it is fully dry.