In a career in which she broke through as many barriers as she waterproofed, Dorothy Lawrence can deservedly be called, “The First Lady of Roofing and Waterproofing.” Her résumé is loaded with technological and material advancements that are still in use today.

In a career in which she broke through as many barriers as she waterproofed, Dorothy Lawrence can deservedly be called, “The First Lady of Roofing and Waterproofing.” Her résumé is loaded with technological and material advancements that are still in use today. After over 60 years in the roofing and waterproofing industry, she still had an unmatchable passion for the business.

She was fully active in the material manufacturing business she founded over 50 years ago, and possessed one of the finest minds that this industry has produced in keeping water out of buildings. Her wisdom and sage advice over the years was beneficial to scores of architects, including Frank Lloyd Wright, engineers, owners, and Division 7 contractors.

Lawrence, 83, of Aurora, Ohio, died Feb. 19, 2008. She was the owner of the Laurenco Company and fellow member of A.S.T.M.

Meeting the Famous

Her meeting with Frank Lloyd Wright during the construction of the Guggenheim in New York City (one of his most famous projects) in the late 1950s was memorable. Her waterproofing materials were applied on the below-grade sections of the building. When they met at the project meeting, Wright insisted that Dorothy remove her high-heeled shoes since she was taller than he was.

“He was an amazing man, but he could be difficult to work with,” Lawrence once said. “For instance, he felt that concrete waterproofs itself. This is an opinion that I do not share.”

Mies van der Rohe was another famous architect that Dorothy worked with. Her waterproofing material was applied on three of his projects in Chicago, including his famous 860 & 880 Lakeshore Drive high-rise designs, which were completed in the early 1980s.

Over the past 50 years, her roofing and waterproofing systems have been applied on a plethora of identifiable buildings, including the John Hancock Building in Chicago; The Empire State Building in New York; and numerous airports and hospitals throughout the country.

Dorothy was intimately involved with most of these projects and could recite many of the most intricate details of each one. “I had to be present on these sites during construction because I was a woman material manufacturer and at that time I could not afford to have a problem,” she once said.

Experience in Construction and Product Development

In an industry dominated by men and short on praise, Dorothy gained the respect of her peers the old-fashioned way - she earned it. She began her lifelong career in the roofing industry at the age of 16 working for her father’s roofing company. Perry Miller was the majority owner of Industrial Roofing and Sheet Metal Inc. (the company later became Industrial First) in Cleveland, Ohio, until 1972. At the time of his ownership it was one of the largest roofing companies in the country.

She began working part-time during the summers in the accounting department, but it was not long before her insatiable curiosity took over. “Father had three daughters and had long given up the idea of having a son to take over his business,” she said. “Fortunately, his oldest daughter (Dorothy) was somewhat of a tomboy and as I continued to work for the company I grew to like the industry.” Dorothy would often leave the office to help load trucks and assemble materials and equipment for the projects.

Her responsibilities grew and she eventually became a project manager, a position that provided her the opportunity to gain firsthand experience with actual field conditions. Her presence on the roofs was quite an anomaly in the 1940s.

“My father tried to keep the boys in line and told them not to curse in my presence, but I still heard all of the whistling and cute remarks,” she said. “I would blow a kiss to the boys with the most clever lines.”

The men quickly found that her beauty was equally matched by her intelligence and determination. “I think I gained their respect the first time I jumped into a tractor trailer truck - in a skirt - and successfully backed the flatbed into position,” she said.

She also designed and developed the first hot bitumen roofing tankers and systems for pumping and handling hot asphalt and coal tar pitch to the roof areas. Much of this technology is still used today.


Upon her graduation from Ohio Wesleyan University in 1946 with a B.A. and minor in chemistry, Dorothy turned her attention to product development. Her first product, developed in 1946, was “Glasfab,” which is a woven glass fabric for roofing and waterproofing applications. The material was designed using a “yellow jacket” white resin, asphalt and coal tar pitch. It was developed in compliance with ASTM D 1668 and Federal Specification No. HH-C-466 a and b. She sold the Glasfab technology to Koppers Company in 1966. The weave and coatings developed for this product are still used today.

While working as Manager for the Lexington Supply Company (a supply company founded by her father in 1944) Dorothy developed the design for the original “Lexsuco” insulation clip in 1948. She sold the clip technology and the Lexington Supply Company to Lexsuco in 1951.


Dorothy married Jack C. Lawrence in 1949 and they formed the Twinsburg-Miller Corporation in 1950. Twinsburg-Miller, or TWIN-MILL as it was known, manufactured and sold roofing and water- proofing products such as Glasfab to roofing and waterproofing contractors and distributors. When they sold the Glasfab technology to Koppers in 1966, Jack Lawrence went to work for Koppers as Technical Director. At that time, Dorothy formed the Laurent Corporation, which is still in the business of manufacturing and marketing Laurenco Waterproofing Systems, Laurenco Roofing Systems, plus privatelabel fabrics (glass, cotton, jute and polyester), felts (polyester and glass) and various coatings and adhesives for others serving the roofing and waterproofing industry.

Jack Lawrence passed away in 1971, but Dorothy continued to run a highly successful company while raising their two children, Caroline and Jonathan. Under Dorothy’s strong guidance the company prospered despite economic setbacks, male bias, and a fire that destroyed their manufacturing plant in the early 1990s.

Jonathan Lawrence began work at Laurenco on a part time basis in 1977 and has worked full time since 1983. He worked closely with his mother in product development, technical duties, and in 1994 he designed all of the present computerized manufacturing equipment in their Leavittsburg, Ohio, plant. Jon also took on additional duties of project field inspections due to Dorothy’s limited mobility on construction sites. However, if you sent an asbuilt detail to Dorothy, she would have happily chatted you up on the phone and conveyed her comments.

Recognitions and Awards

Dorothy was the first women member of the ASTM Committee D08 on Roofing, Waterproofing and Bituminous Materials in 1972. Since then she was an active member and strong supporter of the group’s mission to improve the quality of materials used in the construction industry. Dorothy has served as the Sub Committee Chairman for D08.19 and as secretary to D08.03, D08.04, D08.05, and D08.22. She was active in the committees and attended the meetings on a regular basis. She was awarded with ASTMs highest honor, “The Award of Merit,” for her many contributions to the roofing and waterproofing industry. This earned her the title of “Fellow,” a recognition that has been bestowed on only a select few industry members.

Dorothy was also a member of the American Concrete Institute since 1976. She served as Chairman of the Committee 515: Coatings from March of 1986 through March of 1990. She cited ACI and the Portland Cement Association as excellent sources of information regarding the study of concrete technology, which is particularly important in waterproofing applications.

“It is like the line in that old Protestant Hymn - ‘You build your faith on rock, not sand,’” she once said.

Featured Speaker

Over the years she was a featured speaker for many industry associations and organizations imparting her great knowledge on topics ranging from roofing and waterproofing design and material technology to “Waterproofing Nuclear and Fossil Fueled Generating Plants.”

During the time when we were still building nuclear plants, Laurenco was the only product commissioned to waterproof these highly sensitive structures.

This was further testament to Dorothy’s product development and technical capabilities considering these structures absolutely cannot leak. These are also the projects that she looked back on with great personal satisfaction because of the technical challenges that they presented.

Sage Advice

If you had ever met Dorothy Lawrence you would immediately have known that she was not sensitive about stating her opinion. This, she felt, was a benefit of her experience. It is also due to the fact that the world she grew up in was a far cry from the politically correct atmosphere that dominates the landscape in these times.

Once you have discussed an issue with her you would also realize that her straightforward advice was not only always correct, but it is beneficial to the audience she addressed. This industry has truly benefited from this woman’s ageless and timeless grace and elegance. The future applicators and leaders of this industry should benefit from her sage advice.

Her background, experience and expertise are impressive regardless of the fact that she was a woman in a male-dominated industry. She managed to climb to the highest points in the industry in expertise and respect despite the objections of some men. She did not consider herself as a pioneer for women in the industry, but she was. When asked how the role of women in the industry has changed over the years, she quickly responded, “It is much nicer now and generally women are more accepted on construction sites.”

Dorothy did not believe that gender should provide any undue privileges and cautions: a woman must still perform to be effective. “If a woman is capable to complete the task at hand, use her,” she once said. “If she is not capable, get her out the way. Of course, this is true of both men and women. If you get into this business, you must know what you are doing.”

Her advice to roofing and waterproofing contractors was also straightforward. She strongly believed that the key to a company’s success is based on the skill level and quality of the crews. “When I worked for my father we had a key group of men that were good workers who could also be effective foremen,” she said. “We built crews around these men in the busier months and we combined them as a crew in the slower months. They worked year-round and they stayed loyal to us for many years.”

She believed that intelligent foremen and superintendents are the key to a company’s success. “Superintendents that work in the field are now rare birds,” she said.

She also felt that successful crews are comprised of people that can be trained to do repetitive work at a consistently high quality. And she felt the best companies maintain their key personnel and do not get in the habit of hiring workers from the union halls on an as needed, projectto- project basis because this does not build a long-term workforce. “When we look at potential applicators for our roofing and waterproofing systems, I always look at the experience level of the foremen and crews, their experience with application of similar systems and materials and how long they have been with the company,” she said. “After all, these are the people that are actually installing the material.”

Trade Unions

Dorothy felt that the trade unions could play a bigger role in training the workers that are the future of this industry. “The most important issue that I would like to see stressed in training is a discussion of why we complete details the way we do,” she said. “If the applicator had a better understanding of why things are done a certain way, the overall effort would improve.”

Dorothy remembers the way application techniques were passed along by the older generations. “On-the-job training by qualified journeymen to apprentices was the way that these trades were advanced for generations,” she said.

Dorothy also believed that “pride of equipment leads to pride in workmanship.” She cringed when she arrives at a jobsite and saw dirty or broken- down equipment because it could give the impression that the company was not committed to excellence.

Her advice to contractors was to “maintain the equipment and clean the trucks prior to bringing them to the jobsite.”

“Show the people that you are working for that you are proud of what you do,” she said. “Always fix all broken equipment before it leaves the yard.”

The old adage that “first impressions are lasting impressions” holds true here.

In Conclusion

Dorothy spent countless hours with architects, engineers and designers. Over the years, she occasionally performed some consulting work in the roofing and waterproofing industry giving appropriate design solutions on problems encountered by other manufacturers or design professionals.

One issue that she observed was that designers tend to design solutions that are onesided and create other ancillary issues. She cited one belowgrade waterproofing detail on a beam at grade in which the architect designed scuppers through the structural slab to allow for water runoff. The slab was sloped to the scuppers; however, since the slab was located below grade, ground containments and debris plugged the scuppers and water was constantly ponded in this area. The solution was to fill in the scuppers and waterproof the structural slab. Dorothy stated, “It does no good to solve one problem and create five others.” Material development and technology had been the lifeline of her career. In 1955 she attended Case Western Reserve University in Cleveland, Ohio, to supplement her education in chemistry and geology. These educational advancements proved to be beneficial as she was instrumental in developing cold process roofing and waterproofing materials.

“The key to proper material development is that the developer must know what the materials do,” she said.

The biggest concerns she has regarding the material development industry at the time was that products were sales driven and designed to only solve one problem. The technical people rarely go into the field to see how the materials perform in actual conditions.

In 1953, she designed the first waterproofing and roofing sheets to utilize rubber. These were the first modified bituminous systems. They were first manufactured with coal tar pitch and asphalt bases. In 1957, she modified the formulation for the only asphalt/synthetic rubber modifications that duplicated coal tar pitch.

To this day, Laurenco products are manufactured in a similar manner. She believed that cold process materials are the biggest advancements in this industry and after over 50 years and millions of square feet of her applied roofing and waterproofing materials in some of the most critical facilities in the world.

Dorothy Lawrence was directly responsible for some of the most important technological developments in the roofing and waterproofing industry. Her tireless effort over the past 60 years was beneficial in the advancement of material technology and application techniques.

Although she had been directly involved with some of the most famous projects and lists a litany of “firsts,” her fondest achievement was her ability to help contractors succeed throughout the years. This is a testament to the true character of a phenomenal woman.