Construction Type: Alteration
Type of Contract: Lump Sum
Size of Project (SF): 31,694
Contract Magnitude: Large ($1M+)
Duration of Project: 24 Months
Percentage of Labor Self-Performed: 98.8

Work Performed

Harbor Roofing and Contracting, Inc. (“Harbor”) was subcontracted in early 2020 by Clark Construction Group, LLC (“Clark”) to perform the roofing, waterproofing, and metal roofing on the George Washington University (GWU) Thurston Hall renovation project in late 2020.

The project, which began in November of 2020, included the full renovation of an antiquated building into a modern day, first year student dormitory that would serve as the centerpiece of new dormitory development at GWU. As we at Harbor always say, projects that incorporate not just the waterproofing and membrane work, but the overburden (aesthetic items, amenity items, green-friendly products), are the best projects to showcase as they demonstrate our functional capabilities to maintain watertightness, as well as our ability to provide utility and beauty to a building’s rooftop space.

Scheduling roofing and waterproofing work – disciplines that bookend a project – is always difficult considering the focus and skill required to maintain a project’s critical path. Coordinating access, street permits for lifting/hoisting, planning manpower, and drying in the building as quickly as possible is of utmost importance to the Clark and GWU.

Further, for a project beginning in the winter months of 2020, there are unique challenges performing roofing and waterproofing, as many of your products, adhesives, and primers are temperature sensitive. Special means and methods such as heated insulated boxes are used to warm materials to their application temperature.

Harbor installed crystalline below grade waterproofing at the interior basement foundation walls of the building, along with components that ensure proper drainage. The basement waterproofing included the subcontract excavation work of Diversified Site Works, LLC, a fellow chapter member.

At the main roof level, demolition was performed by others prior to commencement of our work. Harbor installed a Henry hot rubberized asphalt membrane roofing system (“HRA”). The HRA consists of the hot fluid-applied membrane, a protection layer, insulation to code (ranging from R-25 to R-33), filter fabric, and then overburden. At the courtyard and middle terraces, the same HRA system was installed with differing overburden.

At the bridge and the penthouse roofs, a fully adhered reflective PVC membrane system was installed as at these areas the roof membrane would be exposed to UV exposure.

The overburden is the star of this project. A green roofing system by Green Roof Outfitters was installed at the main roof level.

There were two types of pavers installed on this project. The first is a type of paver most in construction will recognize, a 2’x2’ concrete paver. This paver is equipped with a locking mechanism locking the pavers down to the underlying pedestals to tie them together in such a way that individual pavers will not blow out of place or off the roof in a severe wind event. Also, these pavers provided a high level of solar reflectivity, providing energy savings and a nice aesthetic effect to the building.
At the courtyard and the middle terraces where amenity areas for seating and recreation were desired, Harbor installed Nitterhouse porcelain pavers on an elevated pedestal system.
The HRA system includes a green roof assembly and paver component incorporation into its warranty, providing the owner a sole source of contact should any future issues arise with respect to their warranty on this project. Both the HRA and the PVC systems will provide the owner with a twenty (20) year “No Dollar Limit” warranty.
One of the last scope items to be completed on the project was the standing seam metal roofing at the interior elevations of the courtyard that was referred to as the lanterns. These special architectural features are very cool but also very difficult to access. Working with Clark, Harbor was able to make an agreement where our sheet metal crews were able to use swing stages to access these locations and install metal roofing.

As previously mentioned, this project had several challenges not typical of every rooftop renovation project. Weather, access, and the project’s location downtown definitely increased the difficulty of the project, but the emergence of COVID-19 during the project, and the departure from Harbor’s project team at the beginning of the project made this one of the most difficult projects Harbor has completed in the past few pandemic years.
At completion, this project spanned over twenty-four (24) months and incurred multiple crews, three (3) superintendents, multiple foremen, and over twenty thousand (20,000) man hours of labor to complete. Harbor mobilized truck cranes and hoists, subcontracted excavation work, and contributed to Clark’s successful delivery of the project to GWU in 2023.


“The Clark and Harbor project team worked together to deliver the customer a safely completed, high quality product.”

-Christian Orfanopoulos, Clark Construction