I have a TPO roof on my Rockwood. For self-levelling I use Alpha Systems sealant for TPO but Dicor has a TPO sealant, too. For the vertical sides, I use ProFlexRV. If you have a rip in the TPO get some Eternabond tape. There are lots of threads here discussing Eternabond.
2011 Rockwood Signature Ultra Lite 8293SS, 12K Equal-i-zer
2016 Ford F-250 XLT SuperCrew, 6.2L, 4x4, 6'9" bed, 3.73
2010 Rockwood Roo 23SS (2012 - 2014)
2009 Ford F-150 XLT SuperCrew, 5.4L, 4x4, 5'6" bed (2012 - 2016)