My 2013 ST29SS has an Alpha TPO roof. Alpha recommends Spic and Span and no protective treatment. I believe you need to know if you have a TPO or EDPM membrane.
Proper care and maintenance of your Alpha Systems roof membrane is critical for years of trouble-free performance. Normal maintenance is simple, easy and requires no special materials.
Periodic cleaning (three to four times per year) is the primary maintenance required. Alpha Systems recommends using a non-abrasive household cleaner, such as Top Job or Spic-N-Span, and a medium-bristled scrub brush. Do not use any harsh or highly-abrasive products during cleaning. When finished cleaning, remember to thoroughly rinse the roof and sidewalls in order to remove any soap residue and to prevent streaking. CARE SHOULD BE EXERCISED WHEN WORKING ON TOP OF YOUR UNIT! THE ROOF MAY BECOME SLIPPERY WHEN WET.
DO NOT USE ACETONE, OR ANY OTHER PRODUCTS CONTAINING PETROLEUM DISTILLATES, ON THE ALPHA SYSTEMS ROOF MEMBRANE. USE OF THESE PRODUCTS WILL DAMAGE THE MEMBRANE.
Periodic inspection of the roof, during cleaning, is highly recommended. Check the membrane for signs of damage. Check the caulk/lap sealant used in all termination areas, and around all accessories and fasteners, for signs of cracking or voids.
The roof membrane can be cut or punctured by sharp objects. Caution should be used when placing any articles on the roof. If damage does occur, the membrane can usually be patched.
Alpha's membrane is quite inert and will resist weathering well. It does not require the periodic application of products to protect it from ultra-violet light or ozone. In fact, these products can often cause damage to the roof membrane.