With on site installed flashing. You can find TCR-014 installation instructions as well as the TCC installation manual on our Skylights For Less website. This process is pretty simple. Build a site built curb and flash it with custom on-site flashing, then screw the Curb Mounted TCR Sun Tunnel into the newly created curb. To get the longest lasting, lowest maintenance solution, this is the way to go. The major drawbacks to the curb mounted method is that you are limited to the larger Sun Tunnels (14 & 22 inch diameters) and you must have the curb mounted installation which may not be the look you are going for. Preparing a curb for the Sun Tunnel on an existing roof can be pretty complicated to flash well, for this reason the curb mount works really well on new metal roof installs, but the flush mount method below works well on Sun Tunnel retro-fit installations.
If you would like to install the flush mount Sun Tunnel like the TGR-010, TMR-014 or the larger TGC-022, it is possible. The pitfall is that the surfaces that connect between the metal roofing and the Sun Tunnel will need to be sealed with a high quality roofing caulk. Utilizing caulk to create a watertight seal is not as preferable as the curb mounted, fully flashed method. This is because you will likely need to get up on the roof and touch up or re-caulk the joints at some point. Utilizing BASF NP-1 caulk as suggested in the video is extremely important. This caulk is extremely flexible, will withstand the heat and is very durable. This caulk should hold up in any weather condition for at least 10 years. Many contractors are reporting longer time frames. Skylight Solutions has created a detailed video of the TMR-014 installation in the video shown below. If you would like to install the TGC-022 on a metal roof then this same installation method would work well.
If your metal roof is going to be newly installed, it would be best to install curbs for your Sun Tunnels and curb mount them from day one. If you would like to retro-fit a Sun Tunnel into an existing metal roof, adding and flashing a curb can be pretty complicated. In this instance you may want to seriously consider installing a flush mount with the method shown by Skylight Solutions in the YouTube video above. It is a very doable installation with a beautiful flush mount look. The flush mount install really makes the Sun Tunnel look more integrated into the roof and in many ways is more pleasing to the eye.