Penofin's products are meant to be used on wood surfaces, not PVC or composite decking. Please refer to Trex's [Decking Care & Cleaning Guide](https://documents.trex.com/is/content/Trex/trex-decking-care-and-cleaning-010820pdf.pdf#_ga=2.155176446.776250573.1628632134-137737600.1628105527) for additional information.