Interior vs Exterior Window Cleaning: A Complete Guide to Crystal Clear Windows

Keeping your windows sparkling clean requires understanding the distinct challenges and techniques for interior window cleaning versus exterior window cleaning. While many homeowners attempt to tackle both inside and outside windows with the same approach, each presents unique considerations that can make the difference between streaky disappointment and professional-looking results.

The Key Differences Between Interior and Exterior Window Cleaning

Environmental Challenges

Interior windows face entirely different contamination than their exterior counterparts. Inside, you're dealing with cooking grease, fingerprints, pet nose prints, and household dust. The controlled environment means less aggressive cleaning methods often suffice.

Exterior windows battle against bird droppings, tree sap, road grime, mineral deposits from sprinkler systems, and weather-related buildup. These contaminants are typically more stubborn and require stronger cleaning solutions and techniques.

Accessibility and Safety

Interior window cleaning offers the luxury of stable flooring and easy access to cleaning supplies. You can take your time, use extension tools comfortably, and clean in any weather conditions.

Exterior cleaning presents safety challenges, particularly for multi-storey homes. You'll need to consider ladder safety, weather conditions, and potentially invest in specialised equipment like squeegees with extension poles or water-fed pole systems.

Best Techniques for Interior Window Cleaning

Preparation is Key

Before touching the glass, remove all window treatments and clear the surrounding area. This prevents damage to curtains or blinds and gives you unrestricted access to the entire window surface.

The Right Tools for Inside Work

• Microfibre cloths: Two cloths minimum – one for cleaning, one for drying
• Spray bottle: For controlled application of cleaning solution
• Rubber squeegee: 25-30cm width works well for most residential windows
• Lint-free paper towels: For final touch-ups

Step-by-Step Interior Process

1. Dust first: Remove loose dirt and debris with a dry microfibre cloth
2. Apply cleaning solution: Work from top to bottom in overlapping strokes
3. Squeegee technique: Start at the top corner, pull down in straight lines with slight overlap
4. Edge cleanup: Use a damp cloth to clean squeegee marks from window edges
5. Final inspection: Check for streaks in different lighting conditions

Interior Cleaning Solutions

For regular maintenance, a simple mixture of warm water and a few drops of dishwashing liquid works brilliantly. For greasier buildup (common in kitchens), add a tablespoon of white vinegar to your solution. Avoid commercial glass cleaners that contain ammonia, as these can leave residue in enclosed spaces.

Mastering Exterior Window Cleaning

Weather Timing Matters

Never clean exterior windows in direct sunlight or on windy days. Early morning or late afternoon provides ideal conditions. The cleaning solution won't dry too quickly, giving you time to work without leaving streaks.

Essential Exterior Equipment

• Water-fed pole system: For high windows (professional investment)
• Extension squeegee: 35-40cm width for efficiency
• Scrubber sleeve: To agitate stubborn dirt
• Bucket with measurement marks: For consistent solution mixing
• Drop sheets: To protect plants and outdoor furniture

Tackling Tough Exterior Contaminants

Bird droppings: Soak with warm soapy water for several minutes before gentle removal with a plastic scraper.

Tree sap and paint spots: Use white spirits on a cloth, followed immediately by soapy water to remove residue.

Mineral deposits: Mix equal parts white vinegar and water, let sit for five minutes, then scrub gently with a non-abrasive pad.

Professional Exterior Technique

1. Pre-rinse: Hose down windows to remove loose dirt
2. Scrub thoroughly: Use your scrubber with generous cleaning solution
3. Squeegee from top: Work in reverse-S patterns for efficiency
4. Detail edges: Clean window frames and sills with a cloth
5. Final rinse: Quick hose-down of the cleaned area

Safety Considerations for Both Methods

Interior Safety

While seemingly safer, interior cleaning has its hazards. Ensure electrical outlets are protected from water spray, and be cautious with cleaning solutions around pets and children. Always ventilate the area well when using any cleaning chemicals.

Exterior Safety

Never attempt to clean windows above ground level without proper equipment and training. For second-storey windows, consider hiring professionals or investing in a quality water-fed pole system. Check ladder condition before use, maintain three points of contact, and never overreach.

When to Call the Professionals

Consider professional services for windows higher than single-storey, if you have mobility limitations, or when dealing with severely stained glass that hasn't responded to your efforts. Professionals carry insurance and have specialised equipment for challenging situations.

Maintenance Schedules

Interior windows: Monthly cleaning in high-traffic areas (kitchens, children's rooms), quarterly elsewhere.

Exterior windows: Quarterly as a minimum, with spot-cleaning after storms or particularly dusty periods. Homes near busy roads or under trees may require monthly attention.

Frequently Asked Questions

How often should I clean interior vs exterior windows?

Interior windows typically need monthly cleaning in high-use areas and quarterly elsewhere. Exterior windows should be cleaned quarterly at minimum, with monthly cleaning for homes in dusty or high-traffic areas.

Can I use the same cleaning solution for both interior and exterior windows?

While you can use basic soapy water for both, exterior windows often need stronger solutions to tackle environmental contaminants like tree sap and mineral deposits.

What's the biggest mistake people make when cleaning windows?

Cleaning in direct sunlight tops the list. The cleaning solution dries too quickly, leaving streaks. Also, using dirty tools – always start with clean cloths and squeegees.

Should I clean interior or exterior windows first?

Clean interior windows first. This allows you to see any missed spots or streaks from inside before tackling the more challenging exterior cleaning.

How do I prevent streaks when cleaning windows?

Use proper technique: work quickly before solutions dry, maintain consistent squeegee pressure, and always finish with a lint-free cloth on edges. Quality tools make a significant difference in streak prevention.