I don't recommend Tegaderm at all. Many folks getting a skin tear are elderly or with fragile skin from steroids, and trying to removed the Tegaderm can be impossible without causing more skin tears. I have seen patients from nursing homes covered with Tegarders, with wound fluid bubbling up and leaking out the sides.
For skin tears with a flap, just irrigate with normal saline, put the flap back down over the tear, and you can secure with Steristrip or put a non-adherent dressing on it, like a foam (Polymem), vaseline gauze, or Adaptic. You may only need to change dressing every 2 or 3 days. Telfa pads seem to stick, don't use them. Here is a good article on skin tears:
http://findarticles.com/p/articles/mi_qa3977/is_200005/ai_n8894280/?tag=content;col1
Oldiebutgoodie (certified wound RN)