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.
2019 Rockwood Signature 8290BS, Reese Revolution pinbox and B&W Patriot 18K hitch
2016 Ford F-250 XLT SuperCrew, 6.2L, 4x4, 6'9" bed, 3.73, w/ snow plow & camper pkgs.
2011 Rockwood Signature 8293SS (2015 - 2018)
2010 Rockwood Roo 23SS (2012 - 2014)