Next time as a test, only spray one section and compare it to the others.

I used to regularly spray the underside of my deck, but I came to the conclusion that it wasn't worth it. The reason that I needed to spray my deck at all was because I was letting my grass grow too tall in between mowings and as a result things weren't mulching like they should be. I started mowing more frequently and as long as the grass was dry the underside never got caked up. No more oiling the deck, only spraying it out with a hose when I was through.

 

Next time as a test, only spray one section and compare it to the others.

I used to regularly spray the underside of my deck, but I came to the conclusion that it wasn't worth it. The reason that I needed to spray my deck at all was because I was letting my grass grow too tall in between mowings and as a result things weren't mulching like they should be. I started mowing more frequently and as long as the grass was dry the underside never got caked up. No more oiling the deck, only spraying it out with a hose when I was through.

I've used the Fluid film for at least 10 years and came to the same conclusion. As long as it was dry not much of a difference. I did a reno this year and what used to be my lawn was overtaken by a weed that created a solid mat on the ground. This stuff is perpetually wet and sticks to everything.

 

I used it on my deck to test it and it didn't help me at all. I use it on my snowblower chute too.

 

Definitely not worth the time, effort, or added cost.