The green, black, or gray growth that you may have noticed on the outside of your house is most commonly one of three things: algae, mildew or mold.
All three are caused by moisture and organic material.
Algae is the most common, mildew is the most superficial, and mold is the most concerning.
Algae
Algae is green and often collects on siding, pollen, dust and tree sap that gets on your home. You might often find it in shaded areas and areas where moisture is typically present. Algae is not harmful for your home but it doesn’t look great, and it can create a permanent stain on your siding or be a precursor for things that are actually harmful, so its best to get rid of it.
Mildew
Mildew is a surface fungus that shows up on painted surfaces. Mildew is not damaging to your home but spreads rapidly and it will make your house appear neglected. Good news is that it is easy to clean!
Mold
Mold is a serious health concern and not something you want to find on your home. While exterior mold is less of a health concern than interior mold, it often spreads and can damage siding over time.
Why Your House Grows This Stuff
The local area of southeastern Pennsylvania is a very wet, green landscape. We experience precipitation, humidity and a lot of vegetation which are all recipes for moisture buildup.
Every house in Montgomery, Chester, Bucks, and Delaware County is essentially sitting in a petri dish half the year. If your house is in southeastern Pennsylvania and it’s been 2–3 years since the last wash, some level of green or black buildup is practically guaranteed.
Can I Clean with Bleach?
Yes, bleach will kill algae and mildew on contact. But you should be careful about bleach solution running off your siding and onto your grass or plants. At SUDS, the first thing we do on every job is spray vegetation with a bleach neutralizer specifically to prevent harm to your plants.
Another thing is, full-strength bleach can cause discoloring on your home and other surfaces such as a wood deck. We professionals use the right concentration of cleaning solution applied with proper equipment for your specific siding material.
When to Worry
Worry if you see mold. That’s the biggest one because it likely indicates a moisture problem with your home that needs to be addressed. If you get your home professionally washed and see rapid growth that returns within a few months, that is also a sign for concern.
We Can Help
If your house is looking a little… green… schedule a wash with SUDS here or give us a call. We’ll bring the suds, protect the plants, and send you home to a house that looks brand new. Because your home deserves a spa day too!