Guest User
6/6/2012
Our metal rooof is 10 years old and we have black stains around a couple vents. Why? How do you remove them and do we need more ventilation.
Todd Miller
Classic Products, Inc.
6/7/2012
They probably can be cleaned with a light detergent or trisodium phosphate. Usually when I have seen this it is because there is a lot of moisture existing those vents. That moisture then has a tendency to fall, condensing on the roof. Keeping the roof regularly moist and damp eventually allows biological growth and hence the black marks. Adding additional exhaust vents to the roof in order to disperse the moisture, or finding other ways to reduce the moisture in the attic, should be helpful.
Info @windowsonwashington.net
An informed customer is our best customer.
6/7/2012
+1 TSP works well and is mild. Check with the metal manufacturer for compatibility just to make sure you are staying inside their guidelines.

If you would like to reply to this thread, please log in. If you do not have an Ask the Experts forum user account, create one here.

Find a Contractor

Get Started Today

Take the first step to increasing the value of your home with a great looking, durable, fire resistant and energy efficient metal roof. Browse our list of qualified MRA Member Roofing Contractors in your area for a free consultation and estimate.