A must-have for people who are looking to fix their doors and windows, the DAP Windows & Doors 100% Silicone Rubber Sealant does a lot of things at once. Not only does it fix any defects on your door, whatever the material may be, it creates a tight seal which resists crumbling, chalking and cracking of the surface after its application. Let the sealant settle and cure for a bit to get the most watertight seal you can achieve which will keep mildew out of the surface as well.