How much is a "ton" and how many layers did you put on your roof? I put three coats on (entire 4.75 gallon bucket... I rolled until there was none left). Data sheet
specs 2 gallons. I have bought another gallon to use as touch up. The park I'm in had some idiot "trim" the trees we are parked under and dropped a tree limb on the bus. Good thing it was the bus and not some flimsy RV. So after they were all done with the trimming of the branches, I climbed up the ladder and touched up the scrapes. Then I hit a few spots that looked "light" while I was climbing around on the ladder and had the stuff out (probably put stuff in places that didn't need it). I like having a partial can on hand. I do need to buy a quart can and pour whats left into it . I also keep a tube of the clear elastomeric roof sealant (Henry 212) on hand as well. I think having a "roof repair kit" on hand is a smart idea.
As for putting the stuff inside, you may want to read the Health Product Declaration
as given some of the ingredients may cause cancer. While it's okay on the roof (encapsulated in the material) it's not something I want slowing grinding into dust inside my home. You might want to contact Henry's Customer Support
and ask your question there.