Skylights allow natural light to flood a room, giving the room a warmth that lightbulbs just can't match. They are also the perfect viewing window to observe the moon and stars at night. Acrylic skylight are a good choice for those who are afraid glass skylights may break from an impact such as a falling tree branch during a storm. Acrylic skylights are crystal clear when they are new. Wind, rain, snow and overhanging trees can change that pretty quickly. The dirt and tree sap can create a hazy or dirty film over it taking away a pleasant view. Cleaning an acrylic skylight with the wrong types of cleaners can permanently damage the crystal clear view. Some cleaner scratch the surface especially if they have abrasive quality. Some cleaners can cause a permanent cloudy haze over it.
In a large bucket or pail, mix 2 tablespoons of liquid dish soap into a gallon of water. Gently stir the detergent and water so it is well blended. Do not use dishwasher detergent because these detergents are too strong and harsh for acrylic.
Wet a microfiber cloth in the soapy water and wipe it. Go in one direction, in straight lines only. After each pass from end to end of it, rinse the microfiber cloth in a second bucket filled with clean water. Microfiber cloths will not cause scratching and they hold dirt well. Just do not rub the dirty cloth over it because the dirt on it may be abrasive which is why you only make one pass in one direction at a time.
Wet the microfiber cloth in soapy water and wipe it one more time.
Rinse the soapy water off the sky light and dry the acrylic surface with a clean microfiber cloth. Bring a long garden hose up on the roof with you, it makes rinsing and washing much easier than carrying yet another bucket up on the roof with you.
If you have stain that you could not remove with the soap and water, use 3M plastic cleaner or Permatex Plastic Cleaner. Spray whichever cleaner you chose onto the acrylic surface and scrub with a microfiber rag until the stain is gone.
If you have tree sap stuck to your acrylic skylight, spray Orange Glo onto the sap, let it sit for a minute or two and scrub off with a microfiber cloth.
Rinse it thoroughly with plain water and dry it with a microfiber cloth to avoid water spots. You can also use a clean, well worn cotton or flannel rag.
Do not use standard spray glass cleaners on acrylic skylights as they may ruin the acrylic.
Avoid using strong cleaners and abrasive sponges, powders or steel wool on an acrylic skylight as these can permanently damage the acrylic. Even mild abrasives can leaves small, thin scratches that end making it look like it is dirty. These tiny scratches are permanent and will ruin your skylight.
Use care when working on a roof and follow all safety precautions.
Don't attempt to clear snow and ice from skylights. If its have snow and ice, it's pretty likely the roof will also have the same slippery mess, which makes walking on the roof very dangerous.