National Tile and Stone Authority

National Tile and Stone Authority

8534 Jumilla Avenue
Winnetka, CA 91306
Office: 818-744-4949

Experts in tile and stone selection and installation, including pools and spas, NTSA provides forensic investigation, failure analysis, inspections and consultations regarding stone, ceramic, glass mosaics, and many other materials. Greg Andrews and Gil Chotam are both well-trained professionals with many years of experience and individual areas of expertise. We would be pleased to discuss the aspects of your case with you.

Greg is one of the country's leading pool tile experts with a unique and specific expertise in glass and stone mosaics.
His experience includes specialties in product selection, waterproofing, installation and forensic investigation analysis of all submerged tile and stone applications. Greg has published numerous articles on the topics of tile and waterproofing in submerged applications and is frequently engaged as a speaker and instructor at conferences across the country.

Gil's expertise is ceramic tile and stone installation in residential and commercial applications with a special emphasis on stone selection and installation. He has also spent over 15 years in consulting and litigation support. Gil has managed several large commercial tile and stone companies.

Areas of Expertise
  • Brick & Stone
  • Concrete/Cement
  • Construction
  • Construction Damages
  • Construction Site
  • Contractor's Licensing
  • Failure Analysis
  • Flooring
  • Lath & Plaster
  • Pools & Spas
  • Scheduling Delay & Analysis
  • Tile
  • Waterproofing


Available Upon Request