If you live anywhere in New Castle County, Delaware, you already know what summer does to the outside of a house. From Bear and Glasgow out in 19701, to the older colonials in Trolley Square and the Highlands around 19806, to the newer neighborhoods spreading out through Middletown and the MOT corridor in 19709, it is the same story every year. Humidity climbs, pollen blankets everything in yellow-green dust, and the north-facing walls start showing that familiar dark streaking and soft green fuzz. By August, what was a clean exterior in April looks like it has been neglected for years. It has not been neglected. This is just what Delaware summers do.
True Blue Pro Wash serves all of New Castle County with professional exterior house washing and soft washing. We are not power-washing siding at high pressure and hoping for the best. Soft washing uses low-pressure application of biodegradable cleaning solutions that actually kill the organisms causing those stains, rather than just blasting them temporarily off the surface. Gloeocapsa magma, the cyanobacteria behind black roof streaks, does not stop at your roofline. It migrates. The same organism shows up on vinyl, stucco, and painted wood siding across Hockessin, Pike Creek, Christiana, and every neighborhood in between.
Why New Castle County Exteriors Get Dirty So Fast
The Mid-Atlantic climate is genuinely tough on building exteriors. Wilmington and the surrounding county average humidity levels that stay elevated from May through September. Afternoon thunderstorms deposit moisture that never fully evaporates before the next round arrives. Add in the tree canopy that covers neighborhoods like Westover Hills, Greenville, and Brandywine Hundred, and you have a recipe for accelerated biological growth. North-facing walls get the least sunlight and hold moisture longest. That is exactly where you will see the heaviest mildew and algae buildup, and it is the side of the house most visible from the street in plenty of New Castle County neighborhoods.
Freeze-thaw cycles in winter push the problem further. Moisture works into siding seams and paint films, and biological growth that was dormant through January comes back stronger in March. By the time pollen season hits in April and May, the exterior surfaces are already compromised. Pollen bonds to a surface that has biofilm on it far more aggressively than it bonds to clean material. One soft washing appointment each year resets the clock and keeps the exterior in a condition where routine maintenance actually works.
What Exterior House Washing Covers
When True Blue Pro Wash washes a home in New Castle County, we are not just running a hose over the front elevation. A full exterior wash addresses the entire envelope of the house. That includes all four walls, soffits, fascia, window frames, and the foundation skirt. We also rinse gutters and downspouts as part of the exterior cleaning process, though gutter interior cleaning is a separate service. For homes with attached garages, covered porches, or screen enclosures, we treat those surfaces as part of the same job. The goal is a complete reset, not a partial improvement.
Siding Types We Clean in New Castle County
- Vinyl siding, the most common material in Bear, Glasgow, and Middletown neighborhoods built since the 1980s
- Painted wood and fiber cement siding, common in Trolley Square, the Highlands, and older Wilmington homes near 19806
- Stucco and EIFS, found throughout Greenville and the higher-end custom homes in 19807
- Brick with painted or sealed surfaces, common in New Castle city proper and older Newark properties around 19711
- Hardie board and composite siding on newer construction throughout the Pike Creek corridor and Hockessin, 19707
Neighborhoods and Zip Codes We Serve Across New Castle County
True Blue Pro Wash is based in the Delaware and greater Wilmington area, so we are not driving two hours to your job. We know the neighborhoods. We have washed houses on Greenhill Avenue in the Highlands and on the newer cul-de-sacs out in the Glasgow area of Bear. We know that properties in Brandywine Hundred along the 19810 corridor tend to have more tree overhang and moss pressure than the open-lot homes in Townsend and Odessa. We price jobs based on actual conditions, not a flat rate that ignores what your specific house looks like.
- Wilmington city proper: 19801, 19802, 19805, 19806, 19807, 19810, covering Trolley Square, Highlands, Westover Hills, Brandywine Hundred, and Greenville
- Newark and Pike Creek: 19711, 19713, including Christiana and neighborhoods near the University of Delaware
- Hockessin: 19707, a heavily wooded area with high algae pressure on north elevations
- Bear and Glasgow: 19701, high-density residential with many vinyl-sided colonials built in the 1990s and 2000s
- New Castle city: 19720, a mix of older brick rowhouses and mid-century single-family homes
- Middletown, Odessa, and Townsend: 19709, the fastest-growing residential corridor in the county
How Often Should You Wash Your House in Delaware?
For most homes in New Castle County, one exterior soft washing per year is the right interval. If your property has heavy tree cover, sits in a low-lying or shaded area, or has north-facing walls that stay damp, you may benefit from scheduling in early spring before pollen season peaks and again in late summer before the leaves fall and trap moisture against the siding. Homes with lighter exposure and good airflow around the structure can often go 18 months between treatments without visible buildup. We are happy to walk your property on an initial visit and give you an honest recommendation based on what we see, not a upsell you do not need.
What to Expect on the Day of Service
We confirm the appointment the day before and arrive in a clearly marked truck. Before we start, we close any windows you may have left cracked, move anything fragile near the foundation if you have not already done so, and walk the exterior with you so you can point out any areas of particular concern. The soft wash solution dwells on the surface for several minutes, then we rinse at low pressure. On a typical two-story colonial in Bear or a cape cod in Pike Creek, the full exterior wash takes two to three hours. We do not leave until the rinse water running off the siding is running clear. You can call or text us at (302) 757-9755 any time after the job if you have a question about the results.
Frequently Asked Questions
Is soft washing safe for vinyl siding on homes in Bear and Glasgow, DE?
Yes. Soft washing uses low-pressure water delivery, typically under 100 PSI at the surface, combined with a biodegradable cleaning solution. This is far safer for vinyl siding than high-pressure washing, which can force water behind panels, damage seams, and void manufacturer warranties. The cleaning agents we use are appropriate for residential siding and are rinsed completely before we leave.
How long does exterior house washing take to dry in Delaware's humid summers?
On a warm day with moderate breeze, siding is typically dry to the touch within two to four hours. In higher-humidity conditions common to New Castle County from June through August, full drying can take longer, especially on north-facing walls. We recommend keeping windows closed for at least two hours after the wash to prevent any residual moisture from working inside.
Will soft washing kill the green algae and black mildew on my north-facing walls?
Yes. The cleaning solutions we use are specifically formulated to kill algae, mildew, mold, and the cyanobacteria responsible for black streaking. The key difference from a standard pressure wash is that we are killing the organism at the root, not just removing the visual surface layer. This means the results last significantly longer, typically one full year or more depending on your site conditions.
Do I need to be home during the exterior washing appointment?
You do not need to be home, but we do ask that someone is available at the start so we can confirm window and door status and point out any specific concerns. Many of our New Castle County customers in Hockessin, Middletown, and Brandywine Hundred have us complete the work while they are at work. We send a completion text with photos when we are done.
How much does exterior house washing cost in New Castle County?
Pricing depends on the square footage of the home, the number of stories, the type of siding, and the level of biological buildup. A typical single-story ranch in Newark or New Castle runs less than a large two-story colonial in the Highlands or Greenville. We provide free on-site estimates with no obligation. Call us at (302) 757-9755 or submit a request online to schedule your estimate.
Can you wash a house in Wilmington zip codes like 19806 or 19810 without damaging older painted wood siding?
Yes. Older painted wood siding requires a careful approach, and soft washing is actually the safest method available for it. We adjust both the pressure and the chemical concentration based on the age and condition of the paint film. We will flag any areas where paint is already peeling or adhesion is compromised before we start, so there are no surprises. We have washed homes throughout the Highlands, Trolley Square, and Westover Hills with original wood siding and achieved excellent results without any damage.