Economy skylights bite the dust.
Corner seams that aren’t welded are a sure sign of low value skylights. A hidden indicator is the lack of a thermal break. A thermal break isolates the aluminum frame from direct contact with the interior. Without a thermal break heat and cold are transferred to the interior increasing heating and cooling costs. This can also lead to condensation “leaks”—drips caused when warm, moist air condenses on a cold surface just like on a bathroom mirror.
Non-welded seams have spread open over time. 
Caulking the seams and corners is a temporary band-aid at best.
Like for like upgrade.
We replaced the economy domes with Velux CG2/CT2 Dynamic Domes, a high value skylight. Welded corner seams, 100% thermally broken frame with a proprietary moisture wicking system to void any condensation to the exterior. At a competetive price.
CT frame is a coated gray color. 
CG frame has a mill finish. 
Three of the five skylights we replaced.
