We are having a house built in the summertime hot and humid climate of NE NSW. We specified that the extensive Australian mixed hardwood decking (all of it is under cover) should be oiled. The builder's painting subbie wants to use a non-oil treatment. (At this stage, we don't know what, but will be meeting him onsite tomorrow to discuss) Should we stick to our guns or be persuaded to go to a water-based product?