Ten years ago we bought an 1890's balloon framed house that was alum sided in the 50's. On move in we had to replace the roof within 90 days or the house insurance would be dropped. So in the midst of moving family and renovating the interior (iow, completely distracted) I told the roofer to NOT install ridge vents as there were no vented soffits on the eaves, so there was no reason to install them. About 3 years ago, while having a gutter problem looked at, I finally realized that ridge vents *were* installed. Got an estimate of about 1K to have them torn off and capped. I am looking to see if it's possible to just use spray foam to accomplish the same task from the inside of the attic and not have the vents replaced. Any comments appreciated.
Attached are pix of ridge board and closeup of ridge vent plastic mesh.