Roof Cleaning Information

Roof Cleaning Expectations vary Roof by Roof

It’s a common roof cleaning question that we hear from homeowners who just bought a home that has a stained roof:

Will a Roof Stain Cleaner remove all the black streaks, lichen, roof mold?
I want my roof to look like new!

The short answer is that a Roof Shingle Cleaner will improve the appearance of your shingles, but no cleaner is capable of making a roof look brand new.
But a roof cleaner will improve the appearance for very little investment, which makes an attempt at roof cleaning an essential step before deciding to buy a new roof.

So let’s explore what factors affect how well a roof stain cleaner will work.

Roof Stain Severity

Roof Stains go by many names: Roof Algae, Shingle Lichen, Roof Mold or Black streaks. The roof stains have a very predicable triangle roof stain pattern and the longer the stains are on the roof shingles the more effort that will be required to remove them. In some cases we have heard from customers who have had stains for 10yrs, these stains will be VERY difficult to remove. In the end, consider that for every year a stain has been present on the roof it will reduce the effectiveness of a roof cleaner, by 4%. So if you have had stains for 10 years, consider that a roof cleaner will improve the situation by 40% versus if the stain was only 1 year old, the results would be 96% better.

Roof Shingle Age

The age of the Roof Mold Stains is not the only consideration when trying gauge how much better a roof will look. The age of the roof shingles themselves is a factor. First consider that a shingle itself has a useful life, which is typically expressed by its warranty. In other words you can buy a 20yr Asphalt Shingle, or a 30yr Architectural roof shingle and the expectation is that by the end of say 20 yrs, the shingle will need replacement. With that in mind consider that at 10yrs, the shingle is 50% used or half way to needing replacement. The tell tale sign of shingle age is the amount of shingle granules that are washed into the gutters. Just heavy rain is capable of rinsing more granules the older the roof becomes.

So how does shingle age affect my results? The older the shingle, the less it will respond to cleaning attempts. So a shingle roof halfway through its life (say 10 yrs old) will not respond as well to roof cleaning as a 2 yr old roof. The percentages increase as the age of the shingle increases, but a good rule of thumb is every year of age the shingle has reduces the expected cleaning results by 3%, so a 10yr old shingle will show 30% less improvement over a 1 yr old roof shingle. Continue reading →