South Florida remains a testing ground for extreme weather when it comes to the building industry. Despite increasing challenges for the future in regard to sea water rise, hurricanes have been the main cause for much damage and subsequent regulations and building code upgrades in the region. Many of these requirements have influenced codes and also have been adopted in other parts of the county in the world. Having its own testing protocol for exterior building components and assemblies, the roof remains one of the most critical components of any home or building.
In 2014 Sebastian Eilert Architecture completed the first home with an ICF roof, built by Split Level Construction and developed by UrbanEcodev – GaiaMa. The house immediately highlighted a number of key benefits that this roofing system brings with it. To start there is the increased wind pressure strength, resulting in a roof superior to a conventional truss roof assembly. While wood trusses do comply with even the latest edition of the Florida Building Code and remain the predominant choice for builders mostly due to cost, the ICF system is frequently preferred by clients due to the superior performance under extreme weather. The cross section of forming Styrofoam – that remains as part of the assembly, with a steel and on site poured concrete roof make assembly comparable to that of a truss roof. The Styrofoam forms can actually be assembled without a crane as they are light enough be placed manually.
The Styrofoam bases also inherently contribute to an increased roof insulation value, one that is now part of the FBC V5, an R30 value. This is an attractive feature for South Florida, as approximately 80% of heat gain enters a home through the roof. It also allows for Ac dusts and water lines to be part of the conditioned space, preserving heat loss and reducing need for energy for these systems.
On top of the on-site poured concrete most roofing materials can be mounted with existing Miami Dade approvals, such as shingles and tiles. The one downside – metal roof required a secondary layer of sheathing in order to be applied, making it a pour selection at this time over the ICF roof.
Finally, a great side effect of this roofing system is the design freedom it offers for vaulted ceiling and other features underneath the roof. The bottom chord typically creating the flat ceilings under trusses can be framed in any shape desired, or a finish material can be applied directly to the underside of the forms.
While there is still a small cost increase over the truss system, S.E.A. continues to use this type of roof and we will continue to incorporate it into our designs. The new 2 story residence in Coral Gables is the latest project featuring this roof system, creating amazing spaced, specifically the outdoor covered patio.
NOTE: S.E.A is not affiliated with Insuldeck or any other system. The above are our observations based on actual project experience. If you have questions or like to consider us for your own project, please contact Sebastian Eilert Architecture.
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