I have to replace a skylight. I just received the replacement from the manufacturer. When I go to install the new one, what is the sealant? When I was on the roof, I saw the same white sealant used...
In my opinion, use butyl tape between the flange of the skylight and the roof. Then use Dicir Self Leveling (tube) to go over the assembly once it is installed.
When you set the light (with the butyl tape) let it set overnight since the putty will tend to seep out. Once the oozing has subsided, then apply the Dicor.
Use the self leveling because it will set up nice and even without needing to use a putty knife to monkey it around.