The origin of plumbing disputes usually arises from defective work and/or materials. Building plans often lack critical detail regarding specification of water pipes, fittings and connections or it simply gets ignored and inferior pipes and fittings get installed. This is usually the result of trying to save costs, regardless of possible future expense for the owner.
When one deviates from the plan as the building work progresses it’s also easy to make minor changes when something seems better or more suitable as you go along. This usually results in piping and fittings being used that is not suitable. Even if there is no intention to use inferior fittings and piping this happens regularly.
It is of utmost importance to the contractor to take the time to implement the necessary quality assurance processes and eliminate any potential plumbing disputes, but unfortunately there is rarely enough time for this on completion of a project, so this vital inspection often gets overlooked.