Best Way to Clean Mold Off the Outside of Your House
G Power Washing OC Pro Tip: If you see green, black or dark-colored growth developing on your exterior walls, don't immediately reach for a high-pressure washer. The safest and most effective cleaning method depends on the surface and the type of buildup.
What homeowners commonly call exterior "mold" may actually be mold, mildew, algae or another type of organic growth. These contaminants commonly develop on shaded or moisture-prone areas of stucco, siding, painted surfaces, under eaves and other exterior surfaces.
For many homes, the best approach is a professional soft washing process that uses an appropriate cleaning solution, controlled application and low-pressure rinsing rather than aggressive pressure.
Why Does Mold and Organic Growth Appear on Exterior Walls?
Exterior surfaces are constantly exposed to moisture, shade, dirt and environmental contaminants. Areas that remain damp or receive limited sunlight can provide conditions where algae, mildew and other organic growth become visible.
Common problem areas include:
- North-facing exterior walls
- Shaded sides of the house
- Stucco underneath rooflines and eaves
- Areas near landscaping and irrigation
- Walls with limited sunlight or airflow
- Vinyl and other exterior siding
- Painted exterior surfaces
What Is the Best Way to Clean Mold Off a House Exterior?
The first step is identifying the exterior material and evaluating its condition. Stucco, painted siding, vinyl siding, brick, stone and wood should not automatically be cleaned using the same pressure or chemical concentration.
For many painted, stucco and siding surfaces, a controlled soft washing process is preferable to aggressive pressure washing.
A typical professional exterior cleaning process may include:
- Inspecting the exterior surface and identifying sensitive areas.
- Protecting nearby landscaping, fixtures and other areas when necessary.
- Applying an appropriate exterior cleaning solution.
- Allowing the treatment time to work on the organic buildup.
- Using controlled agitation when appropriate for the surface.
- Rinsing the exterior using controlled low pressure.
- Inspecting the surface and treating remaining areas when appropriate.
Should You Pressure Wash Mold Off Exterior Walls?
Not necessarily. More pressure does not automatically mean better cleaning.
High pressure can be inappropriate for certain stucco, painted surfaces, siding, wood and other delicate exterior materials. Excessive pressure may damage paint, force water into openings or leave visible cleaning marks.
Professional exterior cleaning is about selecting the correct combination of cleaning solution, dwell time, agitation when appropriate, water flow and pressure for the particular surface.
For delicate exterior surfaces, learn more about our professional house washing and soft washing services.
How to Clean Mold and Mildew From Stucco
Stucco is extremely common throughout Southern California and requires particular care. Aggressive pressure can potentially affect painted finishes or damage deteriorated areas of the surface.
We generally approach stucco cleaning by first evaluating the condition of the finish and determining whether a controlled soft wash treatment is appropriate. Organic buildup is treated before the surface is carefully rinsed.
Older paint, existing discoloration, oxidation, cracks and other pre-existing conditions may remain visible after cleaning. Exterior washing removes appropriate surface contamination; it does not repair damaged stucco or deteriorated paint.
How to Clean Mold and Algae From Vinyl Siding
Vinyl siding can collect algae, mildew, dirt, cobwebs and other buildup, particularly in shaded areas.
Instead of blasting siding with high pressure, an appropriate exterior cleaning solution can be used to loosen organic contamination before controlled rinsing. Care should also be taken around seams, windows, doors, electrical fixtures and exterior penetrations.
Can You Use Bleach to Clean Mold Off the Outside of a House?
Sodium hypochlorite-based solutions are commonly used by professional exterior cleaners to treat certain types of organic growth. However, concentration, surface compatibility, application method, surrounding materials and landscaping protection all matter.
Using an overly strong mixture or applying chemicals incorrectly can damage plants, discolor sensitive materials or affect certain finishes.
Never mix bleach or sodium hypochlorite with acids, ammonia or other incompatible chemicals. Follow the product manufacturer's directions and safety precautions.
Protect Plants and Landscaping Before Exterior Cleaning
Landscaping protection is an important part of professional house washing. Depending on the property and cleaning method, plants and surrounding areas may need to be pre-wet, protected during treatment and thoroughly rinsed afterward.
Professional cleaners should also evaluate windows, doors, electrical fixtures, outdoor furniture and other sensitive areas before beginning the cleaning process.
Why Soft Washing Is Often Better Than High Pressure
Soft washing focuses on treating the contamination instead of attempting to remove everything through water pressure alone.
This approach can be appropriate for many exterior surfaces because it allows the cleaning solution to work on algae, mildew and other organic buildup before controlled rinsing.
The correct method still depends on the surface. There is no single pressure setting or cleaning mixture that is appropriate for every house.
How Often Should You Clean the Exterior of Your House?
There is no universal schedule. How quickly exterior buildup returns depends on shade, moisture, landscaping, irrigation, surrounding trees, weather exposure and the exterior material.
Instead of waiting until heavy staining develops, homeowners can periodically inspect shaded walls, areas under eaves and sections near landscaping for new organic growth.
When Should You Hire a Professional?
Professional exterior cleaning may be the better option when the home has extensive organic growth, difficult-to-reach areas, multiple stories, delicate surfaces or areas where water intrusion could be a concern.
An experienced exterior cleaning company can determine whether pressure washing, soft washing or another cleaning method is appropriate for each part of the property.
Professional House Washing in Orange County & Inland Empire
G Power Washing OC provides professional house washing, soft washing and exterior cleaning throughout Orange County and the Inland Empire.
Our services include exterior wall washing, stucco cleaning, siding cleaning, cobweb removal, algae and mildew treatment, exterior window washing, concrete cleaning and complete exterior property cleaning.
We also provide professional pressure washing and roof cleaning services for residential and commercial properties.
G Power Washing OC Pro Tip
Don't automatically use maximum pressure on a dirty exterior wall. Identify the surface and contamination first. For many types of organic buildup, proper treatment followed by controlled rinsing can provide a better cleaning approach while reducing unnecessary pressure on the surface.
Need Help Cleaning the Outside of Your House?
If your exterior walls have black streaks, green algae, mildew or other organic buildup, G Power Washing OC can evaluate the condition and recommend an appropriate cleaning method.
G Power Washing OC
Professional Exterior Cleaning Since 2003
Licensed & Insured – CSLB #1117502
Call or Text: 714-322-2383
Email: info@gpowerwashingoc.com
Estimates are always free.
