You might have excessive moisture or just want to clean between the domes of your skylight. Or maybe you need to replace the domes. It’s not hard to do, but there is a proper procedure. Follow this guide.
1) Disassemble unit by removing hex head screws around perimeter of the aluminum retaining angle and remove top angle frame.
2) Remove domes from the curb. Then separate and remove old gasket seal that is between domes.
Sometimes the domes can be really stuck together. Don’t pull too hard or you might break the plastic. Instead, use a knife to run between the domes and separate the gasket used to keep the domes together. If you’re replacing the domes, then you don’t need to separate the old ones. Just remove both together.
3) Clean domes. DO NOT USE: Glass cleaners, window cleaning sprays, kitchen scouring compounds, alcohol, or solvents such as acetone, gasoline, benzene, carbon tetrachloride or lacquer thinner. These chemicals will destroy the plastic. Use a soft cloth with plastic cleaner or mild soap and plenty of lukewarm water, applying only light pressure. Rinse with clean water and dry by blotting with damp cloth or chamois.
4) Set inner/bottom dome back on frame and apply a 1/4″ bead of 100% silicone caulk (GE or Dow brand 100% silicone) to the middle of the flat sides of the dome leaving a 1″ to 2″ gap at lower corners. The gap of silicone in the corners helps to release moisture.
5) Set outer dome in place and reinstall dome retaining angle. Be careful to NOT apply too much pressure to retaining angle when replacing fasteners, so that the domes may allow for any future moisture to weep out from between the domes.