Causes and Fixes to Discoloration of House Paint
Posted on December 18, 2019
Keeping your home looking fresh is no easy task, especially when it comes to maintaining the paint. Over time, even the best paint job can show signs of wear, discoloration, or stains caused by various factors. But how do you know if it’s just dirt, or if there’s a bigger issue at hand? Here’s a guide to the most common causes of house paint discoloration, along with solutions to help you restore your home’s pristine look. Click here for a look at some other common questions our customers have.
Common Causes of Paint Discoloration and How to Fix Them:
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1. Mildew
What it is:
Mildew is a type of fungal stain that typically thrives in wet, humid conditions but can appear in colder climates as well. It often shows up as black, green, or other dark stains and commonly develops behind trees or shrubs where airflow is limited.
How to identify it:
Apply a couple of drops of household bleach to the discolored area. If the stain disappears after a few minutes, it’s mildew. If not, it may be a different type of stain.
How to fix it:
Use a paint labeled with a mildewcide after thoroughly cleaning the affected surface. This will help prevent future mildew growth.
2. Water-Soluble Extractives
What it is:
Certain types of wood contain extractives that can leach out and stain paint, particularly when water is involved. These stains often appear as red-brown marks caused by the reaction between the wood’s components and water.
How to fix it:
Apply a water-repellent preservative to the wood before staining or priming. Use an oil-based, stain-resistant primer to prevent extractives from bleeding through the paint.
3. Blue Stains
What it is:
Blue stains are caused by microscopic fungi that commonly infect sapwood, especially in moisture-prone areas.
How to fix it:
Temporarily remove the stain using household bleach. For long-term prevention, apply water-repellent preservatives and address the source of the moisture, such as adjusting roof angles or eaves to redirect water.
4. Iron Stains
What it is:
Rust stains, often red-brown in color, occur when iron nails or fasteners corrode over time.
How to fix it:
Replace problematic nails with corrosion-resistant options like galvanized, stainless steel, or aluminum nails. Countersink the existing nails, then caulk, spot prime, and repaint the affected areas.
5. Chalking
What it is:
Chalking occurs when paint gradually breaks down and releases a powdery residue on its surface. This is a common occurrence as paint ages.
How to fix it:
Clean the surface thoroughly by scrubbing away any chalk residue, followed by a proper rinse. Apply a high-quality oil-based primer, then finish with a durable latex topcoat.
6. Resin Brown Spots
What it is:
Knots in softwoods can release resin, causing paint to peel or turn brown over time.
How to fix it:
Before painting, apply a quality primer to all wood surfaces. Use two coats of paint for added protection. Avoid using varnish or shellac on knots, as these can lead to early paint failure.
If you’re noticing any of these issues and need expert help, we’ve got you covered! Our professional painting and repair services ensure your home looks as good as new. Click below to request a free estimate—our team in the Indianapolis area is ready to assist you.
