Why Did My Vinyl Siding Turn Green?

This article was written and published by Mr Roof.

Vinyl siding is a relatively new exterior home solution, introduced in the late 1950s. It came about as an alternative to aluminum siding. Thanks to modern technologies, vinyl siding has come a long way since its early days. Today, this siding choice is one of the most popular for homeowners. It’s affordable, durable, and attractive, with minimal maintenance requirements compared to wood. Yet some vinyl will experience problems – one of which is the siding turning green. Here’s what to know about this issue and when to schedule professional siding services.

Causes of Green Vinyl Siding

Vinyl is a polymer with components that make it especially fit for protecting a home from the elements. Vinyl siding is strong yet flexible and resistant to UV degradation. When installed properly, vinyl siding can withstand 180-mile-per-hour winds and look good doing it. However, no siding material is entirely maintenance free. If vinyl shows green discoloration or staining, typically one of two things is responsible:

  1. Mold. Water dripping onto the area typically causes green mold on your siding. You may have an issue with your gutters or a leaky drainpipe. Minor adjustments can solve these water problems and prevent mold growth on your siding. Getting rid of mold on siding may require help from a professional, for safety reasons.
  2. Algae. Algae may appear green or brown and will stay damp on your siding. Algae growth is mainly a cosmetic issue and can resolve with a bit of scrubbing using a mild soap. Algae may grow due to dirt and dust attached to your siding. Algae feed on these materials. Siding sealants can help prevent algae growth.

Mold and algae are not the same. They have different sources and different requirements for cleanup. You may need a professional inspector to help you differentiate between the two and to select the proper solution going forward. A professional siding contractor can identify the source of the problem, remove existing stains, and help you prevent the same issue from occurring in the future. Sometimes, however, it may simply be time to repair or replace your siding.

Is it Time for Siding Repair or Replacement?

To remove green stains from your siding, first try a solution of warm water and soap. This can often get rid of small amounts of algae on your siding. Stubborn mold may require a mixture of water and chlorine bleach. Scrub siding with a stiff brush, moving from side to side over green stains. Begin at the top of your house and work down. Rinse sections with a garden hose as soon as you finish scrubbing. Point the hose downward to avoid spraying water behind the siding. If stains persist or you don’t feel comfortable cleaning them on your own, contact a professional.

It is typically possible to kill mold, mildew, algae, and fungus and enjoy siding that looks like new again. You may need to pressure wash your siding – a task you should leave to professionals to avoid damaging the material. In some cases, your vinyl siding may be overdue for repairs or replacement.

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