Board of Directors

Megan Cross-Wilkinson


Megan Cross-Wilkinson has 6 years of experience in the building science industry in the fields of existing building, new construction and forensics/litigation. She currently works in the Oakland office at RDH Building Science Inc., and has managed projects in California, British Columbia and Ontario, Canada. Megan holds a B.A.Sc. in Honours Environmental Engineering from the University of Waterloo in Canada. She is a member of the Association of Professional Engineers and Geoscientists in British Columbia and the California Board for Professional Engineers and Land Surveyors (PELS) in California. 

Bill Gillette


Bill Gillette has been marketing and providing technical sales support for roofing and waterproofing systems over the past 25 years.  Most recently relocating to the San Francisco Bay area in 2010.

Bill lives in Danville, CA with his daughter, Isabella. 

David Markman

Vice President

David Markman P.E. (CA) is a Senior Building Science Consultant with Morrison Hershfield's San Francisco Bay Area office.  In his twelve year career he has enjoyed providing building science consulting on buildings ranging from single family homes to iconic museums.  David's focus is working with clients, including Architects, Contractors, and Owners to understand each projects unique circumstances and designing the appropriate solutions.

Rob Worthing


Mr. Worthing has over 20 years of experience in the building enclosure consulting industry. He is a Senior Consultant at Allana Buick & Bers, Inc., with extensive knowledge of roofing and waterproofing systems. While his role on any given project varies, he generally performs a variety of services including but not limited to: condition assessments of existing roofing and waterproofing systems, report development, design investigation with destructive testing protocols, preparation of design development (DDs) documents and construction documents (CDs), peer
review, bidding phase, development of addendum documents, construction administration and project closeout. Mr. Worthing has a unique ability to apply a blend of technical knowledge, tangible field experience, and sound business judgment for each individual project to find the best solution for the Client.


Eric Smith

Director at large - Industry

Eric Smith works for Johns Manville in the Preferred Accounts group typically servicing design professionals and building owners.  He has been with JM for over 6 years and has been responsible for product development, sales, marketing, training programs as well as the JM solar energy program.  


Prior to working for JM Eric worked as a manufacturing engineer as well as a design engineer and project manager in the solar energy sector.  He holds a bachelor’s degree in mechanical engineering, a professional engineering license in the state of CA, and an RRO certification from the RCI.


Tom Berger

Director at large - Consultant

Thomas (Tom) Berger has over 29 years’ experience in the design and construction industry.  He is the founding and Managing Principal for DTR Consulting Services.  Prior to founding DTR in 2002, his experience ranged from an Architectural Project Manager, Construction Administrator/ Field Inspector, CM Program Manager, Carpenter, Facilities Planning Manager, Technical Specifier, Forensic Investigator, and Office Leader in various national architectural firms.  Leading an expanding role in building science design & construction validation, he leads his firm in assisting design clients in the selection of appropriate exterior skin wall, roof assemblies, and the almost forgotten area, the 6th side, below grade assemblies.

Tom has received numerous professional certifications and awards, as well being part of numerous award winning projects over the length of his career.


Jonathan Stafford

Director at large - Consultant

Jonathan Stafford is a Senior Project Manager in the Building Technology Division of Simpson Gumpertz & Heger.  Jonathan has 20 years of experience in the investigation and design of major commercial, institutional, and residential buildings for waterproofing issues including roofs, plaza decks, and below-grade spaces.  He consults with architects, contractors, and building owners in the design of the building envelope for new products and to analyze and repair water intrusion problems and construction defects for existing structures.  Jonathan is a licensed Professional Engineer in California and is a Roof Consultants Institute Registered Roof Consultant.

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Dave Johnson

Director at large - Industry

Dave Johnson work as the Northern California District Manager for SOPREMA. collaborating with consultants, contractors and building owners. In his 6 years with SOPREMA, he has been responsible for sales, marketing and contractor training.


Before joining SOPREMA, Dave worked as an architect after receiving his BS in Architecture from UW-Milwaukee.

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Joseph Joslin

Director at large - Industry

Mr. Joslin is based in San Francisco and leads the Technical Business Development efforts in the Western USA for Owens Corning.

He specializes in fire/life safety issues, thermal, moisture, and air dynamics in building envelopes; exterior claddings and unitized curtain wall assemblies; acoustics; below grade insulation, plaza decks, low slope and vegetative roofs. He assists architects, engineers, and contractors with the applications and impacts on building performance of Owens Corning’s products and systems.

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Shawn Lecrone

Director at large - Consultant

Shawn LeCrone, RRO, REWO, CD has 17 years of experience in the building envelope industry, consulting, assessment, contracting, project management, designing, and planning. He has enjoyed providing building science consulting primarily for Education type buildings (K-12 and Higher Ed) but also ranging from large commercial, corporate, healthcare to Multi-Family. As Vice President of California Shawn’s focus is to provide client service for all 8 office of PBK and their clients assist with the building envelope design of each project.

Jerome Jeffers

Past President

Jerome Jeffers has over 30 years of experience in design services for the building industry. His building enclosure experience encompasses a wide variety of project types including educational, institutional, commercial, hospitality and residential.  Jerome is a recognized expert in roofing, waterproofing, and exterior wall consulting.  Mr. Jeffers provides solutions to building weatherization issues and deterioration to building structures. Mr. Jeffers has earned the Registered Building Envelope Consultant (RBEC) certification from RCI, the most prestigious certification for the roofing, waterproofing, and building envelope consultant practice.