Esin Pektas,The Falcon Group

Living in a city with one of the most beautiful skylines, New Yorkers are discovering that their flat roof can, with professional design help, become a valuable outdoor space to enjoy the view, drinks, sunbathing or watching memorable events such as 4th of July fireworks.

Converting your flat roof into a recreational space requires a professional engineer’s structural evaluation for the proposed additional load from people, planters, deck furniture and all appurtenances. Without proper structural support and approval from the Department of Buildings, it is illegal and dangerous to use a rooftop for recreational purposes. Also, if your building is an individual landmark or located in a landmark district, Landmark Preservation Commission approval will be required.

Besides structural evaluation, a design professional should be engaged to investigate waterproofing properties of the existing roofing system and surrounding façade elements and penetrations (parapet and bulkhead walls along the roof perimeter, railings, antennas, flag poles, mechanical equipment, piping and curbs etc.). This investigation can entail observations, non-destructive moisture testing such as Infrared Thermography or investigative probes depending on the visibility of the existing roof conditions, type and age of the roof and roofing warranties in affect. If your existing roof is covered with a warranty, the new recreational roof installation must conform to the manufacturer’s specifications. Consulting the scope of proposed recreational roof design with the manufacturer is recommended to avoid cancellation of the warranty.

In case of excessive aging or poor conditions of the existing roof, replacement of the roofing system might be necessary. As such, it is recommended that a comprehensive roof stripping down to the underlying deck and the subsequent installation of a new roofing system be performed throughout. Some important considerations are the height of top of the parapet walls or railings from top of the walking surface must be kept 42 inches minimum and if a wood deck installation is being considered, the coverage must be limited to 20% of the entire roof with prohibited barbecuing on the surface.

Although, roof replacement might have higher initial cost, conversion to recreational space can instantly increase the value of the property.

As with any reconstruction project, the work should be undertaken and completed with the highest quality, final work product and with minimal inconvenience to the facility. The professional is responsible for preparing a suitable, cost effective, design and construction specifications for the proposed improvement. There are several aspects of a recreational roof installation project that must be followed to ensure the building is receiving both a quality work product and workmanship. Failure to achieve these results can be detrimental to the new roof system and may result in added expenses to the facility overtime. If your building is embarking on a recreational roof installation project, you should confirm that your professional provides, at minimum, the following services:

New recreational roof must be adequately supported, compliant with the relevant building codes, energy analysis requirements of NYC Energy Conservation Code (NYCECC), and documentation standard of the Department of Buildings (and Landmarks Preservation Commission, if applicable).

Verify that the specifications that will be prepared are individualized to your building. It is important to know that you are getting a roof system that is going to meet all of the warranties for the new materials installed. 

Failure of proper flashing or waterproofing may void the manufacturer warranty and may cause premature degradation of the membrane and future leaks. These issues should be properly addressed at the time of the installation so they will not be a future problem.

Make sure that your professional is inspecting the work with qualified inspectors, at roof level. Variations in original construction practices often require field decisions to be made, at roof level. These decisions need to be made by qualified personnel. 

A problem or leak during and after the roof project may occur. Immediate response to these problems should be expected. Twenty-four hour availability should be expected from the professional and contractor for any problem that occurs during or after the work. Resident safety and convenience is essential. Limited production and/or proper inspection will ensure these concerns are addressed.

Recreational roof installation projects are one of the more important reconstruction projects that a building will encounter. Attention to detail is paramount to provide a roof system that will be completely effective for its full useful life. Enjoy the view.

Esin Pektas, RA, AIA, LEED AP BD+C, is a vice president at the The Falcon Group, New York, N.Y.