Waterproofing New Construction Windows In Old Siding
It would help allot if you could post pictures of what one of the windows looks like from the outside. Be sure to get a closeup of the sill in one shot. Most of the time when siding is added, the window trim is wrapped with aluminum. This generally covers all of the exposed wood and the installer should take care of any needed flashing at that time. Depending on the situation, silicone caulking can be added where the aluminum meets the vinyl windows. Caulking is often applied around the outside edge of the window when it is installed, but the method can be different for new construction and replacement windows, thus a picture would be helpful.