As of January 1, 2023, we are now GDA Contractors

Over the last 30 years, The George D. Alan Company became a premium provider of waterproofing and building envelope services in the Southwestern United States. Along the way we opened Oklahoma Waterproofing Company in Oklahoma, Texas Moisture Protection Company in Houston and purchased SEAL-CO, Inc. in New Mexico. It is time for us to become one big happy family. On January 1, 2023, we will all consolidate under one company, The George D. Alan Company, LLC, doing business as (DBA) GDA Contractors

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We’re here to serve you

Service comes first;
People make us great;
Excellence in all we do

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Your friend in the waterproofing business

Whatever the issue, challenge or need, we're here to be your partner in moisture protection. Our team is built to serve and we're proud of our hard-earned reputation for both our service and product.


GDA Contractors is the first contractor in the United States with a Sealant Waterproofing and Restoration (SWR) Institute validated training program

Training Calendar

Our training center calendar keeps you up to date on upcoming events and industry conferences.

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Technical Resources

Get more information on waterproofing products from our Technical Resources directory.

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What the industry says About Us

GDA Contractors are experts in the waterproofing world. Our projects benefit greatly when they are involved in the preconstruction process as they support us by providing valuable constructability and pricing information. During the construction phase, they are a reliable trade partner with a strong focus on schedule and quality. It is always very comforting to know when GDA Contractors is working on our construction projects.

Granger Hassmann Vice President, Adolfson & Peterson Construction

It is rare to find an applicator that cares as much as GDA and their group of companies. They have taken waterproofing to the next level.

Jill Heidorf, Architectural Sales Rep, W. R. Grace

We have enjoyed our partnership with GDA Contractors for close to 30 years. They are the most consistent, trusted, and helpful partners in the business. They are a big part of what we do.

Monte J Thurmond Executive Vice President, South Region Manager, AECOM Hunt

GDA Contractors has done an excellent job…I would definitely recommend this company to anyone with floor issues.

Chad Saltzman, Chief Engineer, United States Cold Storage, Inc.

GDA Contractors are “The Best of Class” in the waterproofing business. Dan has assembled an amazing leadership and employee team who have an outstanding reputation for client focused services on the most challenging projects. We are proud to recommend GDA for over 30 years.

Sam Mullis Partner Mullis Newby Hurst

SSI and the GDA companies have worked together over 30 years . We have always valued the good communication and business practices set forward by the management group at GDA. GDA promotes doing a project the right way, not to just get off the job. SSI values the business the GDA companies have shared with us.

Duane Barnett President SSI

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