The traditional Bermuda Roof has been used as the preferred roofing system in Bermuda for nearly 400 years. In fact the first Bermuda Roof was installed on Carter House, St. George’s, Bermuda (thiophosgene
) in 1640 (nearly 400 years ago) and the original roof is still intact today. How many roof products in Hurricane regions can make this claim? (see Bermuda’s Architecture
The Bermuda Roof has always been built over an open-batten structure (see photo) and material used has always been limestone cut into 18”x12”x1” slate. The slate is bedded in mortar and each row of slate overlaps the previous row by half (9”), therefore all the way up the roof there is approximately 3” of roof material.
Once installed the Bermuda Roof becomes a monolithic structure and as such there is nothing for the wind to grab onto.
In the early 1970s, with the realization that land space in Bermuda for quarrying limestone was becoming scarce, a new Bermuda Roof product was developed. This product was an Expanded Polystyrene (EPS) Bermuda Roof with the EPS being adhered to the substrate, a structural Fiber Cement Board. The EPS was than coated with a fiber cementious base coat and painted with an Elastomeric paint. This new product not only mimicked the traditional Bermuda Roof but add insulation to the structure as EPS does not absorb heat.
The EPS roof has also proven itself in severe weather conditions with three Cat 3 Hurricanes hitting Bermuda in 2003 and two within as many weeks in 2015, while there was some damage reported to the limestone roofs, there was NO UPLIFT reported on roofs using the EPS product. However, because there is the cement board substrate, any loss of EPS will not result in leaks as the cement board joints are sealed during installation creating a water tight roof.