Hi Andi, yes it is possible to fill a 10″ gap with a wire mesh C-channel and the Rail Mount Method. In fact the Rail Mount Method is well suited to this scenario because:

• The “returns” tying the mesh to the rails secure the entire height of the mesh against push/pull and twisting forces, and
• The bigger the piece of mesh, the floppier and wavier it becomes at its edges (near the roof & solar panels); the bend placed in the mesh at each of those locations forces it into a straight line, making it much more likely to form a tight seal and keep out pests.

Here’s a photo of a job I did over a TPU roof. This was probably a 10″ or larger gap. The method used is vanilla Rail Mount Method, with the addition of a rubbery mat between the C-channel and TPU roof as an extra layer of protection to prevent the TPU getting punctured or abraded by the mesh.

That said, there are two obstacles to doing these large C-channels:

1. You’ll need to source large enough mesh– ideally ~3″ wider than the gap you need to fill, so that you can bend two 1.5″ “flanges” to form the C-channel. Slick Tools does not currently sell mesh wider than 10″, though we can arrange a custom order if this is a large job that would be worth the extra expense. If this is a one-off situation, you might consider binding together multiple sections of narrower wire mesh to make a wider piece. This can be done relatively quickly using our Hog Ring Gun. For example, you could put an L-bend into 8″ mesh using the AG Bender™ 7 Rental (or by hand), then bind two sections of the bent mesh together to make a 10″ C-channel.
2. If you plan to use the AG Bender, note the stock machine can only bend C-channels to fill gaps up to about 6.75″. When I did the job in the above photo, I was using a custom version of the Bender which could do the 10″ C-channel. It is actually pretty easy to modify the Bender to do larger channels, but we have not put together documentation on that yet. Feel free to reach out on our Contact page and I can walk you through it over a phone/video call.

Hope that helps!