I've never used this before, but this Discussion with the same questions suggests using "through the roof" http://www.hometalk.com/2248435/q-roof-leak?expand_all_questions=1 Good luck!!! You got this!

Haven't tried to work on a mobile home roof but have been involved in repairing the room on our RV. It's a lot of work. Try googling rv or mobile home roof repair to see what needs to be done.

If the mold is inside I highly recommend using KILZ to paint it! I also have a modular and HAD a horrible black mold issue before using the KILZ

If it's true "black mold", this is a real health hazard. See if your local health department will test it for free, or can recommend an honest, mold testing company. There are mold remediation companies, but this can be expensive. Black mold from a roof leak can grow behind the walls, too, as well as on the ceiling. Good luck!

Your roof seams most likely are not tight. Retighten all screws, if they have pulled thru metal, put washers under screws before re tightening , then use mobile home roof sealer. Next tear off the. Ceiling tiles in the house. They are just a cellulose type foam. You can get replacement tiles of same or do as I did, buy the super thin drywall. Spray those skinny trusses with mold killer before installing. Discard and replace molded insulation. hold insulation up in trusses with upside down clothes hangers as you work. Make sure you mark on side walls location of trusses before lifting drywall. Place constructon glue on bottom of trusses then also screw drywall Into trusses. With those skinny trusses you need real support. Make sure seams are tight and you alternate the drywall as one board length wise the next crosswise. Unless you are good with drywall you may want to hire a professional to either do the entire hang job or just finishing.

Moble home roofs were sealed with driveway tar sealing., using a sqeegy to spread. You can get a Home Depot. You have to do it every year OR every other year. It should be inspected by hubby every year ., usually done every other year., Years ago owned one that's what we used, never had a problem., get it sealed asap., she's gonna have to pull it down from inside and rip that mold out. Don't let it go.