Time for some Henry's 887 silicon roof coating. Look it up. you will be more than happy. I replaced the roof once too. Didn't last at all, 5 years. I will never do that again. Get the Henry's 887 Silicon. Its made for RV'S.
Window shades help alot on hot hot days. As someone said you have a air conditioner or disconnected vent problem. Air should be blowing out pretty good out of the vent.
