Do-It-Yourself Wood Restoration Made Simple!

When To Use RAD Guard On Exterior Wood & Decks

by RAD Products

R-A-D™ Guard Deck & Wood Mildew & Algae Cleaner

R-A-D™ 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. R-A-D™ Guard cleans without pressure washing, scrubbing, or rinsing. Contains no bleach, chlorine, acid, sodium hydroxide, or phosphates.

R-A-D™ Guard is especially effective when used over the top of existing exterior wood or deck stain.

Reasons to Use RAD Guard on Exterior Wood & Decks

There are 2 main reasons to use R-A-D™ Guard on Exterior Wood and Decking. Cleaning off mildew or algae and or preventing mildew or algae on exterior stains and wood.

Cleaning Mildew/Algae on Wood/Decks RAD Guard

R-A-D™ Guard is best used to remove mold, mildew, and algae stains that have accumulated over or on top of any exterior wood or deck stain. This keeps your exterior wood and deck stains looking better and last longer. Just apply and let Mother Nature work with R-A-D™ Guard to clean for you. Mold, mildew, and algae stains will disappear over the next 1-3 weeks without harming your existing stain coating.

Important Note: 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.

Preventing Mildew/Algae on Wood/Decks RAD Guard

The advanced properties of R-A-D™ Guard will also prevent the growth of mildew or algae for 1-2 years when applied over your newly applied exterior wood or deck stain coating. Best to use proactively in scenarios or climates will mildew and algae are prone to show.

Note: R-A-D™ Guard RTU is not used for prepping wood for wood stain application. The primary goal is to remove mildew or algae stains and prevent mildew and algae stains from returning.

R-A-D™ Guard Wood & Deck ADVANTAGES

  • Can Be Applied Over Existing Paints, Stains & Sealers
  • Will not harm Existing Paints, Stains, or Sealers
  • Use on Exterior Wood and Composite Decking
  • Eco-Safe and Pet-Friendly Formula
  • Removes Stains Caused by Mold and Mildew
  • Safe to use on all exterior wood surfaces, not just decks

How R-A-D™ Guard Works:

Step 1: Spray surrounding landscaping with water

Step 2: Pour R-A-D™ Guard into pump sprayer

Step 3: Saturate areas to be applied with R-A-D™ Guard. Surfaces that R-A-D™ Guard is being applied to must be fully dry before application. All paints and stains must be fully dried and cured before the application of R-A-D™ Guard.

Step 4: Once finished applying to all areas of surface, repeat Step 1

Step 5: Step back and let Mother Nature work with R-A-D™ Guard to clean for you

Step 6: R-A-D™ Guard continues to deep clean with substrate penetration

Maintenance: Repeat application every 12-24 months or until new stains appear

Carefully read all cautions and directions on the product label and R-A-D™ Guard SDS prior to use.


R-A-D™ Guard covers approximately 200 square feet per gallon of product. Coverage will vary on application method and substrate.

Have Questions on Using R-A-D™ Guard?

Ask below in the comment section. Pictures will help as well.

author avatar
RAD Products Owner
Scott only carries wood deck stains and wood restoration products that perform best based on his experience using the products and his 30+ years of helping others. Scott has been approached about selling numerous restoration products through the years but selects only the products he has used and trusts to perform.
Notify of
Inline Feedbacks
View all comments
4 months ago

Last year I pressure washed and applied a clear, oil-based sealer to my decks. Now they are green and grey with what I am assuming is a combination of dirt and mold/mildew/algae (decks are pretty shaded). Should I use the cleaner and brightener or the RAD Guard? Or a combination of both? Thanks!

10 months ago

Does the wood have to be below a certain moisture level? i.e. 15% or less to apply this product? Most of the damp areas (receive less sun) of the deck are of course greener. Newly prepped, sanded, and semi transparent, oil based stained in April ’23. Also, the description on the back of the jug says green should disappear within 1-3 days and website says 1-3 weeks. What should I suggest to my customers for realistic result timeframe ? Thanks!

BG Malamut
BG Malamut
1 year ago

What do I use on my fence to remove algae and want to stain or seal?

1 year ago

I’m doing some maintenance on my deck. Some areas had RAD treatment a couple years ago (cleaner, brightener, and transparent stain); others had no treatment. We’re prepping to do another treatment on the whole thing. We’ve used the cleaner, but there are some areas where there was mildew and it hasn’t all come off. What’s the next steps? Clean again? Guard?

1 year ago
Reply to  RAD Products

Pictures attached. It shows up a little more in person than in the photos, but it is subtle. The wood on the rail has been stained using RAD once before. The deck front has not been stained. At this point, both have been cleaned (some areas twice) and brightened.

1 year ago
Reply to  RAD Products

Great, thanks! So I’m going to go ahead and stain these sections. How long after staining should I wait to apply Guard to protect from future mildew/algae growth?

Michael Keighley
Michael Keighley
1 year ago

18 months ago I applied two coats (wet on wet) of RAD Cypress Solid Color Wood & Deck my PT deck after sanding, pressure washing and using your Cleaner and Brightener following all directions. It came out great however I now have some green mildew beginning to show. Should I use RAD Guard or do I need to pressure wash and use the Cleaner & Brightener again?

Would love your thoughts, please comment.x