Here in the Willamette Valley mildew can form on the north side of houses due to the lack of direct sunlight, which keeps the surface cooler and moister. Less sunlight means slower evaporation, which helps the surface stay damp longer promoting mildew growth. Mildew mitigation is an important step when preparing to paint the exterior of your home. One solution? Wash with a solution of TSP.



TSP Safety
- Protective gear: It’s a good idea to wear eye protection, chemical-resistant gloves, and long sleeves and pants.
- Ventilation: Ensure the area is well-ventilated, especially when working indoors.
- Protect surfaces: TSP can damage some surfaces, including metal fixtures and glass. Use plastic sheeting to protect areas you do not want to clean.
- Mixing: Add TSP powder to warm water, not the other way around, to prevent splashing. Typical dilutions range from 1/4 to 1/2 cup of TSP per gallon of warm water, depending on the job.
- Rinse thoroughly: After cleaning, rinse the surface multiple times with clean water to remove all TSP residue. If not completely rinsed, it can leave a white film.
- Protect landscaping: If using TSP outdoors, take care to protect plants from runoff by hosing them down with fresh water both before and after applying the solution.













