It is always better to be overprepared rather than underprepared, and this idea is taken to heart strongly throughout the construction industry. Often, you will finish a job and have quite a few leftover materials that have been paid for but that you have no use for. You don't want to lose money on these items, but what do you do? You can't return them, and your next job might not even need anything close to what you have.
16 October 2019