Casestudy: Marriot’s Frenchman’s Cove

 In Casestudy

A world-class resort in St. Thomas was need of a long-lasting rooftop deck surface durable enough to sustain unpredictable climate swings—SEMCO delivered.


St. Thomas, a luscious tropical retreat located in the beautiful U.S. Virgin Islands, is known for many things, including its diverse weather conditions, ranging from unpredictable rainfall to furious hurricanes. These disparate, and often volatile weather conditions had wreaked havoc on the rooftop event deck of the Frenchman’s Reef and Morning Star Marriott Beach Resort.

Marriots Frenchmans Cove - water damage
Casestudy: Marriot’s Frenchman’s CoveErnstige waterschade aan de kamers onder het dek na de regen.
Marriots Frenchmans Cove - existing conditions
Casestudy: Marriot’s Frenchman’s CoveBestaand betonsubstraat onder tegellaag werd beschadigd door water, wat structurele zwakte veroorzaakte.
Marriots Frenchmans Cove - tiles removed
Casestudy: Marriot’s Frenchman’s CoveTegels werden verwijderd uit het dek in die secties.

Past waterproofing efforts had proved ineffective, so the resort approached SEMCO in April 2015 with the challenge of creating a deck surface durable enough to sustain the diverse climate conditions 365 days a year, while also providing a beautiful, seamless aesthetic appropriate for a world-class resort.

Exploring Alternatives

The resort had attempted to install a new deck using conventional methods, which proved ineffective. Rather than repeating the process of reinstalling and waterproofing the event deck, the property was looking for a more permanent, long-lasting solution.


SEMCO surface engineers evaluated the deck’s condition and determined that the roof tiles were hollow and largely delaminated, and the floor drains faulty. A core sample showed multiple layers of incompatible waterproofing materials. Also, water was seeping into the lower 5th and 4th floor premium suites, raising concerns of corrosion within the steel structure. These challenges were compounded by the following factors:

  • The resort’s remote location
  • Unpredictable weather
  • Short, three-month time constraint for completion
  • Work hour restrictions
  • Strict labor laws in St. Thomas
  • Distance for material holding area
  • Limited property access


SEMCO’s innovative surface engineering team, which thrives on making the necessary adjustments for all their projects, drew up a plan that would effectively:

  • Remove the deck in sections
  • Clean and install a waterproofing cover
  • Build a 1.35% slope to move water from 6” to 1/4” across the 32’ deck
  • Mount a new gutter system to the outside of the building
  • Install a beautiful, durable finish
Marriots Frenchmans Cove
Casestudy: Marriot’s Frenchman’s CoveSEMCO-technici die X-Bond Brown Coat op bestaand betonsubstraat aanbrengen.


Not only has the fashion designer since added seamless stone to two downstairs baths, a downstairs kitchen, and inside fountain, he has also inspired several celebrity friends and close family members to choose SEMCO for their surface and remodeling projects.

Marriots Frenchmans Cove - X-Bond Seamless Stone
Casestudy: Marriot’s Frenchman’s CoveX-Bond Seamless Stone-oppervlak verhinderde dat water de dekstructuur binnendrong.
Marriots Frenchmans Cove - new X-Bond Seamless Stone surface
Casestudy: Marriot’s Frenchman’s CoveWaterdicht X-Bond Seamless Stone oppervlak.
Marriots Frenchmans Cove
Casestudy: Marriot’s Frenchman’s CoveSEMCO X-Bond Seamless Stone werd gebruikt om buitenmuren weer op te knappen.

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Project Information

  • Preparation: SEMCO Nu-Lift Cleaner and Stone Soap
  • Floors and walls: SEMCO ADA Safety Floor and Natural Shield Sealer
  • Project size: 8,200 sq ft
  • Project year: 2016

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