17th February 2023 What material is good for external mouldings? What material is good for external mouldings? We recommend for using our timber mouldings in external applications that you use either Polyurethane or H3 treated pine. H3 treated pine is a natural timber product so will require more upkeep. Polyurethane on the other hand is an excellent alternative to natural timber mouldings for external use as it won’t chip, split, and will look good for years without much maintenance. Both are able to be painted with external grade paints following the instructions from the paint manufacturer.