Premier was contracted by the Globe Unified School District to determine the source of excessive moisture on concrete slabs that caused discoloration of tiles and concrete surfaces, seam openings, bumps and bubbles, efflorescent (migration of salt to the surface of a porous material forming a coating), and adhesive deterioration of the VCT flooring. Two previous investigations were unable to make a definite determination for the source of moisture and/or provide remedial measures to eliminate the problem. We collected two 6-inch diameter concrete cores for testing from two different buildings and collected samples from the base layer and the subgrade. We also created 4’X4’ test sections at representative damaged floor areas, and examined the conditions. Testing results indicated the contractor did not use proper moisture barrier during construction.