How often should you pressure wash your house?

Ask five companies how often to wash your house and you’ll get five answers – usually whatever interval matches their sales targets. Here’s the answer we give our own families: most Carolina homes need a wash every 12 to 18 months. But the right number for your house depends on three things you can check from the curb right now.

The three factors that set your schedule

1. Shade

Algae and mildew need moisture and hate sunlight. A house under mature oaks – hello, Matthews – can show green film in 8 months, while a treeless new build in full sun might cruise past two years. Check your north-facing wall: it’s always the first to go.

2. Water

Live near Lake Norman, a pond, or a creek? Ambient humidity feeds growth year-round. Lakeside homes in Cornelius and Davidson typically need annual washes, no exceptions.

3. Siding type

Vinyl holds biofilm in its texture; brick holds it in its pores; Hardie and painted wood sit in between. None are immune – they just show it at different speeds (and vinyl shows it loudest).

The three signs you’ve waited too long

• Green film on the north side – that’s living algae, and it’s spreading spores to the rest of the wall.
• Black dots that don’t rinse – artillery fungus or set mildew; both get harder to remove every season.
• A driveway you think is gray – we’ve restored “gray” driveways to white more times than we can count.

The schedule we actually recommend

1. Every 12 months: shaded lots, lakeside homes, vinyl siding, or anyone fighting HOA letters.
2. Every 18 months: sunny lots, newer builds, brick and Hardie exteriors.
3. Every 24 months (max): full-sun, low-tree, low-humidity properties – rare around here, but they exist.

Driveways follow the same rhythm; roofs run longer – a proper soft-wash treatment keeps shingles streak-free for 5+ years, which is why ours carries a 5-year promise.

Does washing more often wear out my siding?

Not when it’s soft washed. Low pressure plus detergents is gentler than a year of untreated algae, which holds moisture against the surface 24/7. What does wear siding out: amateur high pressure. If a quote doesn’t mention soft wash for siding, keep shopping.

Want a schedule tailored to your actual house instead of a blog generalization? Send us two photos – we’ll tell you honestly, even if the answer is “wait another year.”