How To Install Transition Trim On A Standing Seam Metal Roof

Looking for installation instructions that show how to install transition trim for a high to low pitch on a standing seam metal roof? We show you how to do an installation on a 18” wide snap-lock panel. 

This article will give basics of how the system is installed including:

• Zee closure installation
• Mastic tape for zee closure
• Placement for zee closure
• How to get everything on the actual pitch break for a proper installation

You can use this article as a guide to follow along with our video below that shows the installation process step by step.

Laying Out Your High to Low Transition Flashing

1. Take the pitch break and set it on top of the high of the panels NOTE: Make sure it flushes out and stays on the same plane as your lower pitch.

Zee Closure Layout

1. You will be running a continuous strip of mastic over the panel to create more of a waterproof seal.
   
2. Mark for your panel on the high where your transition will be. Make the mark for your zee closure ½” from the back.
   
3. Take zee closure and put your tape on and measure to the center of the bottom flange.
   
   
4. Measure back 2 ⅜” and make a mark on the roof panel. 

5. Repeat that process on the other side of the roof so you can snap your chalk lines.

6. Once all highs are marked out 2 ⅜” from the zee closure, go through with a straight edge and mark out the pan of the panel to get an idea of where your mastic tape will be going.

How To Place Your Mastic Tape On Metal Panels

1. With your mastic tape, come up over the top of the high and get it seated well over the corners of the panel. 

       2. Repeat the process at the crease at the snap-lock panel. NOTE: Don’t push it in too tightly or it will start ripping or stretching out the mastic tape.

      3. Once the mastic is set and pressed tightly, remove the liner. 

How To Install Your Zee Closure

        1. Use a drill with your pancake screws. Always consult with an engineer to find the proper screw spacing. 

      2. On this application, we will run about 4 screws per piece of zee closure.

      3. Fasten your zee closure with the proper amount of screws. 

Going through the center, you have a 1” phalange and a 1” fold so you have minimal areas behind the zee closure that you have to caulk. This application helps keep it as watertight as possible. 

How To Use Silicone Sealant and Mastic Tape On Zee Closure

1. Take your 7/8” mastic and run all the way across the top of your zee closure.
   
   
2. Caulk the backside of the highs and fill all the voids with silicone sealant. 
   
   

How To Fasten High To Low Roof Transition Flashing

1. Once your flashing is set in place, fasten with pancake screws about ½” on center. TIP: Pin one end and go to the other end making sure you’re still on your marks and pin there as well before working your way across. 

1. Fasten the front of the transition flashing with pop rivets 12” on center. 

How To Mark Out of Joggle Cleat

Once pancake screws and pop rivets are in place, it’s time to start marking out for the front and backside of the joggle cleat. 

1. Install the joggle cleat 6” from the top edge of the transition trim. 
   
   
2. Mark additional lines 2½” to guide mastic tape.
   
   
3. Fasten mastic tape about ½” below the mark you’ve made. 
   
   
4. Pin both sides of the joggle cleat and then run screws roughly 12” on center. 

How To Cut And Finish Gable Trim At Transition

Cutting the gable flashing at the transition is a difficult process that is hard to explain with words. In order to help you with this step we created a video that shows you all of the steps.

Installing Standing Seam Metal Roofing

Installing a standing seam metal roof is a more complex process compared to other types of metal roofing. Western States Metal Roofing has helped make it easier by creating a standing seam installation video series, with step by step video guides on how to correctly install a standing seam metal roof.

Ready for a quote on standing seam panels? Request a free quote today!