Clarification at 2:33 where we show a right angle and say, "If the seal is properly aligned the flap will create a 45 degree angle." The stop and door meet at 90 degrees; the angle inside the bottom of the seal where it meets the door is 45 degrees.
Transcript: Hi I'm Dan Musick in this video we'll show you how to install PVC stop molding to seal the sides and top your garage door.
The flaps for vinyl stops are mounted either on the sides or the tops. We prefer stops with the top flap because this design allows the door to ride against the hard PVC rather than the soft flap. The only disadvantage to the top flap design is that the vertical and horizontal stops can't be joined without an offset.
To fix this problem cut the top corners of the vertical stops. This will eliminate the gap between the stops. Start by measuring the gaps on either side of the door at the top and bottom as well as each joint. To do this push in on the door and measure the gap you may need to adjust either the garage door opener for the top fixtures to get a consistent gap. The order in which you install stop molding is important. You need to install the overhead board first then the boards on either side so that they intersect with the top board. The reason for this is that when the door closes the flap of the top board is pushed down smoothly and the flaps on either side are moved out of the way preventing them from being torn.
Prep the top board first by driving the nails part way into the board. You do not want them to go through just to be held in place. Place the nails six inches apart on the top board. An important warning did not hammer the nails while the board is bent. This can easily cause the board to crack and break. Lineup the board with the end of the Board flush against the door frame drive the nails into the door frame enough to hold the board up but not all the way through you will need to pry them out again at a later stage.
Repeat this on every other nail up to the midpoint of the door then take the other end of the board mark the excess with a pencil and use a straight edge to extend the mark then cut the board with the implement your choice. We use utility shares but you could also use a hacksaw circular saw or anything else that creates a straight clean edge.
Once you've made the cut hold up the board to check your cut and mark and re-cut is necessary. Now that the board is the proper length you're ready to adjust the position of the board. Since it was initially putting on an angle you may need to pull out some other nails straighten the board then continue driving in every other nail from where you left off.
Close the door to check the seal. If the seal is properly aligned the flap will create a 45 degree angle to adjust an area pull out the nearby nails move the board into position and hammer the nails back in. Next determine the length the side boards. First open the door then hold up the board and mark a line across with a ruler then cut in the same manner as before.
Once you've made your cut check the new length. If the board is too long it will create a bubble. In this case simply re-cut the board and if needed trim the board with a razor blade. Position the board and hammer in the nails 6 to 12 inches apart and partially as before you'll need to adjust them to fix the gap repeat the process on the opposite side then close the door.
Once the door is down check the seal by pushing on the door if there is a gap you'll need to readjust the seal to remove the gap. The reason you push on the door is that when the wind blows it forces the door back and allows the wind in which is especially bad in winter. Before finally hammering in the nails open the door this will prevent you from hitting and damaging the door while driving in the nails.