Where should a sample be obtained when practicable?

When sampling materials for quality assurance in construction, it is essential to obtain samples from the finished product when practicable. This process ensures that the sample reflects the actual conditions and characteristics of the material as it will be used in the project. Sampling from the finished product allows for an accurate assessment of the material's properties, performance, and compliance with specifications.

Obtaining a sample from the raw material source could lead to inaccuracies, as it may not account for any changes that occur during processing or handling. Similarly, taking samples from a storage facility may not reflect variations that can occur in the finished product due to factors like environmental exposure or storage conditions. Additionally, obtaining a sample from a different construction site can introduce external variables that do not relate to the specific project at hand, making it less reliable for quality control purposes. Thus, collecting samples from the finished product provides the most relevant and immediate insight into the material's suitability for the intended use.