what millworkman said.

X3

What's on the roof? Algae? There are products you spray on with a garden hose. Subsequent rain washes off the algae and dirt, but it won't happen instantly.

Thanks for your comments. We get plenty of sun during the day so I don't think it's algae. It's just an old roof and showing its age (like me :-)).

Chisue, I have heard of the products you are speaking about. I am not sure what the contractor plans (would need to verify). For that amount of money I would certainly expect it to be easy on the roof.

I am thinking I will pass on this service and see how it goes. I just don't want to take the risk of making a bad thing worse.

Thanks, again.

Sarah, just know that any buyer is going to expect a discount for the roof even if you price it lower to account for the roof. My ex and I had that with our old house that we sold a few years ago. Our roof was about the same age as yours and we had to give the buyers a $15,000 discount for the old roof.

It all depends. Cross bridges when you come to them. I once sold a house with s completely trashed roof in a week for asking.

I have never heard of cleaning a roof. I'd pass on this as well, but be biting nails at inspection time.

You've never heard of cleaning a roof? Must not live in moss country.

I would try spraying on this stuff - Spray and Forget. I sprayed it on some plastic railing that had mold and it did a pretty good job:
Spray and Forget

Never heard of cleaning a roof? Think Cedar Shakes in Washington State. ;-)

Can you explain the role of labor costs in determining the total price of a roofing project, and how can homeowners estimate these costs?