When you step into a historic church, you’re often greeted by the ethereal beauty of stained glass windows. These intricate, vibrant windows are more than just decorative elements: they tell stories, offer solace, and create a serene atmosphere for worshipers. However, over time, dust, dirt, and grime can obscure the brilliance of these windows. Cleaning church stained glass windows is an essential task to ensure they continue to shine and inspire. In this guide, the pros at One Source, the experts in all types of commercial cleaning services San Diego businesses and organizations trust to coordinate cleaning services that meet all their needs, walk you through the steps to effectively clean and maintain these treasures

Why Stained Glass Windows Need to Be Cleaned

Stained glass windows are a timeless form of art that serves both aesthetic and spiritual purposes. These windows not only depict biblical scenes and religious symbolism but also allow natural light to filter through, creating a breathtaking kaleidoscope of colors inside the church. When these windows become dirty and discolored, they lose their luster and impact. Regular cleaning is necessary to preserve the beauty and historical significance of church stained glass.

When to Clean Church Stained Glass Windows

The frequency of cleaning church stained glass windows depends on several factors, such as the location, condition, and age of the windows, the type and quality of the glass and lead, the level of exposure to environmental elements, and the aesthetic preference of the church. 

Generally, stained glass windows don’t need to be cleaned very often, as they aren’t usually exposed to direct contact with dirt or moisture. However, some situations may warrant more frequent or occasional cleaning, such as when there is:

  • Visible dirt or dust on the glass or lead surfaces
  • Evidence of mold, algae, or fungal growth 
  • Limescale or mineral deposits from water runoff or condensation 
  • Soot or smoke residue from candles or incense 
  • Bird droppings or tree sap 
  • Corrosion or weathering crusts 
  • A special occasion or event that requires a more polished look for the windows

Gathering Your Supplies

Before you begin cleaning, gather the necessary supplies:

  • Mild detergent – Choose a gentle, nonabrasive detergent. Avoid harsh chemicals that can damage the glass.
  • Distilled water – It prevents mineral deposits on the glass.
  • Microfiber cloths – Use lint-free microfiber cloths to avoid leaving behind fibers.
  • Squeegee – A squeegee is ideal for removing excess water and cleaning solution.
  • Soft-bristle brush – Opt for a brush with soft bristles to remove loose dirt and dust.
  • Latex gloves – Protect your hands from cleaning chemicals and oils.

Preparing for Cleaning

  • Assess the condition – Before starting, assess the condition of the stained glass windows. Note any damaged glass or loose lead came, as cleaning can exacerbate these issues. Make necessary repairs before proceeding.
  • Provide ventilation – Ensure proper ventilation to dissipate cleaning fumes and maintain a comfortable working environment.
  • Protect surrounding surfaces – Cover nearby surfaces and pews with drop cloths to prevent any accidental spills or drips from damaging them.

The Cleaning Process

Follow these steps for a thorough cleaning:

  • Remove dust – Begin by gently brushing away loose dust and dirt using a soft-bristle brush. Start at the top and work your way down.
  • Prepare a cleaning solution – Mix a small amount of mild detergent with distilled water to create a soapy solution. Avoid overusing detergent, as it can leave streaks.
  • Test a small area – Before applying the solution to the entire window, test it on a small, inconspicuous area to ensure it doesn’t damage the glass.
  • Clean gently – Dip a lint-free cloth into the soapy solution, wring it out thoroughly, and gently wipe the glass surface. Use a circular motion to avoid streaks. Rinse the cloth frequently to prevent spreading dirt.
  • Rinse and squeegee – After cleaning, rinse the glass with distilled water and use a squeegee to remove excess water and soap residue.
  • Do a final inspection – Examine the window closely to ensure all dirt and streaks are gone. If necessary, repeat the cleaning process.

What to Avoid

When cleaning church stained glass windows, there are some things you should avoid doing because they can harm you or the windows. These include:

  • Using abrasive cleaners or tools such as scouring pads, steel wool, razor blades, or sandpaper
  • Using acidic cleaners such as vinegar or lemon juice
  • Using ammonia-based cleaners such as window cleaners or glass cleaners
  • Using hot water or steam
  • Using excessive water or pressure
  • Using harsh chemicals or solvents such as bleach, alcohol, or paint thinner
  • Cleaning the windows in direct sunlight or extreme temperatures
  • Cleaning the windows without wearing gloves, goggles, or sunglasses

Maintaining Stained Glass Windows

Regular maintenance is key to preserving the beauty of church stained glass windows:

  • Schedule cleaning – Establish a cleaning schedule based on the level of exposure to dust and pollutants. Typically, a thorough cleaning once a year is sufficient.
  • Inspect for damage – Regularly inspect the windows for any signs of damage. Promptly address any issues to prevent further deterioration.
  • Re-lead and repair – When necessary, consult with a professional stained glass restoration expert to re-lead or repair damaged sections of the windows.

Preventing Problems & Protecting Church Stained Glass Windows

Cleaning church stained glass windows can improve their appearance and prolong their life span, but it’s not enough to prevent problems and protect them from deterioration.

Stained glass windows are vulnerable to various factors that can cause damage, such as humidity, temperature changes, UV rays, and pollution. Therefore, it’s important to take preventive measures and protective actions to keep church stained glass windows in good condition, such as:

  • Installing protective glazing or storm windows on the exterior side of the stained glass windows to shield them from environmental elements and physical impacts
  • Installing ventilation or dehumidification systems to control the humidity and moisture levels in the church and prevent condensation on the windows
  • Installing shades or curtains on the interior side of the stained glass windows to block or filter the sunlight and prevent fading or overheating of the glass
  • Applying a protective coating or sealant on the glass or lead surfaces to prevent corrosion or weathering
  • Repairing or restoring any cracks, chips, holes, loose pieces, or missing parts of the glass or lead as soon as possible to prevent further damage or deterioration
  • Hiring a professional stained glass conservator or restorer to inspect, clean, and maintain the stained glass windows regularly and properly


Cleaning church stained glass windows is a labor of love, a tribute to the history and spirituality they represent. When properly maintained, these magnificent pieces of art will continue to inspire awe and reverence in generations to come. Embrace the serenity they offer and let their brilliance shine once more, filling your place of worship with the warm and comforting glow of colorful stories and religious symbolism.

When they need professional church cleaning services, San Diego places of worship can rely on One Source to be their single point of contact. We’ll coordinate all the details involved in making sure you receive the services of an outstanding church maintenance contractor you can trust to ensure your church is always up to the task of ministering to the community. Call us today at (858) 683-6287 to learn how we can make sure you receive the ongoing high-quality maintenance services you and your congregation deserve.