Need to clean the heavy black stains and algae on my asphalt roofs. Any experience with the spray and rinse products out there? Older roof so no chance of any power washing.Also prefer avoiding the home made bleach solutions.

Wet and Forget:

https://www.wetandforget.com/wet-and-forget-concentrate.html

 

Most Costco’s have a good deal on it right now.

 

 

 

Second W&F.   Worked well on a heavily mossed north facing roof 

Thanx guys will consider but looks like w&f needs time? Was hoping for something with real time results so I don't have to recheck or touch up later,  on a mission prepping house for sale gotta finish everything I start.

W&F starts immediately, but you are right it takes time and in my case a second dousing.

The results looks great from the product page... but as indicated it takes time to work. 

Not sure if your totally against using bleach, but i just cleaned my entire house with JOMAX and the stuff melts grime off the surface in minutes. You don't need a power washer to clean with it

I started to power wash the house and realized i was getting no where. 

 

Yes, W&F is going to take time and likely several re-applications.  Any method that is going to remove algae/moss/lichen and stains quicker is likely going to damage the old shingles as well.

5 hours ago, DirtyDigz said:

Yes, W&F is going to take time and likely several re-applications.  Any method that is going to remove algae/moss/lichen and stains quicker is likely going to damage the old shingles as well.

If you need it cleaned asap - like you are going to be selling - think about having pros come do it. 

If you have time to kill, Wet and Forget is the way to go. Apply a couple of times a year. Also acts as a preventive and won't kill your plants. If you have a pro come, they can install some copper strips to prevent recurrence. 

 

6 hours ago, DirtyDigz said:

Yes, W&F is going to take time and likely several re-applications.  Any method that is going to remove algae/moss/lichen and stains quicker is likely going to damage the old shingles as well.

AFAIK, the only real downside to bleach is it can kill the plants around your house. 

 

Any professional who comes to clean is going to use a product that works quickly, and most likely has some harsh chemicals. I would steer clear of any mechanical types of cleaning methods for an older roof. 

Ok, Wet and Forgeti it is. I have time just like to get projects done but spraying the roof is easy enough to do it a few times. 

I used W&F with excellent results, but it took a few weeks. One day the moss was just gone.