As we continue to examine curb appeal we’re going in-depth about roofs and moss — it doesn’t have any appeal when it’s on your roof!
As you look at a house, the roof is a major portion of the view and curb appeal. If you see moss, it must be removed. Not only does it damage roofing materials, but instantly alerts home buyers that this home may not be well maintained!
When I was preparing this post I was shocked at the misinformation about roof maintenance, removing moss and preventing moss that there is on the internet. Please pardon this long post — but for those wanting some detailed information its worth the read! (There are licensed contractors specializing in moss removal and prevention too, so if in a hurry contacting them for a bid would be a good option.)
Removing moss isn’t difficult but can be time-consuming, depending on the condition of the roof and the quantity of moss. It also isn’t a one-step process – the moss needs first to be killed (also known as treated), then removed.
Treating the moss:
1. What to use – Moss can be killed with bleach water or zinc sulfate. Both will not stain a composite roof. Things to consider when determining which way to kill the moss are roofing material, how soon you will remove the dead moss, the color of dead moss on your roof, and weather and long-term prevention.
2. Zinc sulfate is recommended on all composite 3 tab /fiberglass roofs because of its effectiveness and moss/mildew prevention qualities. Zinc takes 4-6 weeks to kill moss depending on concentration, rainfall, humidity, and heat. Zinc sulfate does not stain composite roofs. It usually turns moss from almost black to dark greenish brown. This makes the moss less noticeable on darker roofs and can be an advantage if you won’t be removing the moss quickly. Zinc sulfate is noticeable (unattractive) on concrete tile roofs, and so it is not recommended for this reason only.
Zinc sulfate can be purchased in bulk from a farm store. The main ingredient in the smaller quantities of commercially sold moss killers is zinc sulfate and they can be found at any home improvement store.
3. If you’re in a hurry to sell the house, you could use bleach water. Bleach water usually kills moss in a matter of hours to a few days depending on the weather. It also lightens the color of the moss. Bleach is not a long lasting moss preventative like zinc sulfate, but very effective at killing moss quickly. This allows for moss removal as soon as the moss dries. Bleach water with soap is a great treatment for concrete tile roofs that are gray or red.
Too much bleach can ruin your composite roof! A good recipe is listed below. Don’t pour bleach straight from the bottle onto your roof; this may cause damage to the shingles not to mention anything else it comes in contact with. (siding, fascia, plants).
Bleach recipe: Mix for the bleach water is 3 qts (1 bottle) of 6% bleach (Sodium Hypochlorite) to 3.75 gallons of water. This yields 4.5 gallons of water, almost a full five-gallon bucket. Wet the roof from the bottom up. (So you don’t get drip lines as the bleach water bleaches out mildew stains etc. Again, if you apply bleach too strong it will ruin the shingles.
Removing the moss:
Once the moss is dead it should be removed. This can be done with a stiff broom or wire brush. Start at the top and brush in a downward motion with the direction of the roofing. Use care not to damage the roofing. Tip – cover the gutters with a tarp or plastic and let the dead moss fall to the ground. This eliminates cleaning the gutters after the job is done.
DO NOT PRESSURE WASH! Pressure washing will ruin your composite roof. If in doubt check with any roofing contractor or manufacter.
The roof in our example before/after photos was too damaged and had to be replaced . . . but I think it’s a good example of what a difference a moss free roof can make to the overall curb appeal!
One other tip – don’t use laundry detergent that contains a degreasing agent on your asphalt shingles. Yes, it will prevent moss however the degreasers dissolve the asphalt that holds your composition roof together! This will void any warranty from the manufacturer.
Creative Concepts and Contracting is a licensed contracting and home staging business serving Salem Oregon and specializing in repairs and remodeling. These services make preparing a home to sell easier and effective! CCB#180695
