Mike Silvers, CPRC, Owner, Silvers Systems Inc. and FRSA Technical Director
This question comes up often, especially when a contractor is dealing with replacing rigid insulation that makes up part of the roof assembly in low slope roofing. Although that is where most questions originate, it isn’t the only place where the answer to the question applies. The answer, like many code questions, is not a simple reading of a single code section, but instead one needs to follow a path created by the code. In this article, I will cite some of the code language that deals with the subject and, hopefully, create some road marks along this path.
Since the question involves reroofing, which only applies to existing buildings, we need to start with the following subcode (or volume). There are other sections of the code that deal with reroofing, but most of those are taken from the Existing Building subcode. I will cite this code as it applies to this applicable reroofing work:
CHAPTER 1 – SCOPE AND ADMINISTRATION
PART 1 – SCOPE AND APPLICATION SECTION 101 – GENERAL
Section 101.1 Title.
These regulations shall be known as the Florida Building Code, Existing Building, hereinafter referred to as “this code.” In addition to the provisions of this chapter, the provisions of Chapter 1, Florida Building Code, Building, shall govern the administration and enforcement of this code.
101.2 Scope.
The provisions of the Florida Building Code, Existing Building shall apply to the repair, alteration, change of occupancy, addition to and relocation of existing buildings.
Section 202 – General Definitions
ALTERATION. Any construction or renovation to an existing structure other than a repair or addition. Alterations are classified as Level 1, Level 2 and Level 3. [Note: Reroofing is a Level 1 Alteration].
REROOFING. The process of recovering or replacing an existing roof covering. See “Roof recover” and “Roof replacement.”
ROOF RECOVER. The process of installing an additional roof covering over a prepared existing roof covering without removing the existing roof covering.
ROOF REPLACEMENT. The process of removing the existing roof covering, repairing any damaged substrate and installing a new roof covering.
Section 302 – General Provisions
302.2 Additional codes.
Alterations, repairs, additions, and changes of occupancy to, or relocation of, existing buildings and structures shall comply with the provisions for alterations, repairs, additions and changes of occupancy or relocation, respectively, in this code and the Florida Building Code, Energy Conservation; Florida Fire Prevention Code; Florida Building Code, Fuel Gas; Florida Building Code, Mechanical; Florida Building Code, Plumbing; Florida Building Code, Residential and NFPA 70. Where provisions of the other codes conflict with provisions of this code, the provisions of this code shall take precedence.
This section applies to all alterations, repairs, additions, etc. and indicates that they shall comply with, among others, the Florida Building Code, Energy Conservation subcode. This alone does not answer the question. When we look closer at Chapter 7, which
is the section for Level 1 Alterations, a change in our path is indicated.
CHAPTER 7 – ALTERATIONS – LEVEL 1
SECTION 701 – GENERAL
701.1 Scope.
Level 1 alterations as described in Section 602 shall comply with the requirements of this chapter. Level 1 alterations to historic buildings shall comply with this chapter, except as modified in Chapter 12.
701.2 Conformance.
An existing building or portion thereof shall not be altered such that the building becomes less safe or energy efficient than its existing condition.
Section 701.2 clearly states that you cannot reduce the energy efficiency of the building during the work, but it does not indicate whether additional energy efficiency must be incorporated in such work. Additional information becomes available as we progress on our path to sections more specific to existing roofing. We will come back to this section later in this article.
SECTION 706 – EXISTING ROOFING
706.1 General.
Materials and methods of application used for recovering or replacing an existing roof covering shall comply with the requirements of Chapter 15 of the Florida Building Code, Building, or Chapter 9 of the Florida Building Code, Residential. Roof repairs to existing roofs and roof coverings shall comply with the provisions of this code.
This section does not specifically refer to the Florida Building Code, Energy Conservation subcode. It does exclusively refer to the roofing chapters of the Building and Residential subcodes. Within the Existing Building Code is a separate section titled Energy Conservation which, again, refers to the Florida Building Code, Energy Conservation subcode.
SECTION 708 – ENERGY CONSERVATION
708.1 Minimum requirements.
Alteration subject to this chapter shall comply with the requirements of the Florida Building Code, Energy Conservation.
Based on this, one would think that if the code contains a specific requirement to increase the energy efficiency during reroofing it would be in the Energy Conservation subcode. However, a reading of this section makes it very clear that it is not the case.
CHAPTER 1 – SCOPE AND ADMINISTRATION
PART 1 – SCOPE AND APPLICATION SECTION C101 – SCOPE AND GENERAL REQUIREMENTS
C101.4.2 Exempt buildings.
Buildings exempt from the provisions of the Florida Building Code, Energy Conservation, include existing buildings except those considered renovated buildings, changes of occupancy type or previously unconditioned buildings to which comfort conditioning is added. Exempt buildings include those specified in Sections C101.4.2.1 through C101.4.2.4. Section 708.1 (Energy Code) states: “Alteration subject to this chapter shall comply.” This does not say all alterations must comply. Most importantly, it exempts existing buildings except those considered renovated buildings, changes of occupancy type or
previously unconditioned buildings to which comfort conditioning is added. A typical reroof does not meet these criteria. A renovated building has a very specific definition that again does not apply to most reroofing. To apply, the total energy-related renovations would need to exceed 30 percent of the assessed value of the structure. Typically, if the building is undergoing that level of renovation, a registered design professional will be involved and will specify any changes that are needed to comply with the code.
CHAPTER 2 – DEFINITIONS
SECTION C201 – GENERAL
RENOVATED BUILDING. A residential or nonresidential building undergoing alteration that varies or changes insulation, HVAC systems, water heating systems or exterior envelope conditions, provided the estimated cost of renovation exceeds 30 percent of the assessed value of the structure.
An important item to consider when insulation replacement is part of the work is the change of energy rating of rigid insulation (2014), more specifically polyisocyanurate insulation. Several years ago, a 1.5-inch thickness of Polyisocyanurate had an R-value of 10.0. The current rating is 9.0, so an increase of thickness to 1.7 inches (R 10.3) or additional insulation would be
required to meet the same R 10.0 that originally was installed.
The code does not state that a particular R-value is required for reroofing. Since most of the provisions of the Energy Conservation subcode do not apply to a typical reroof, we are left with the section shown at the beginning of this article – Level 1 Alterations
701.2 Conformance. An existing building or portion thereof shall not be altered such that the building becomes less safe or energy efficient than its existing condition.
I hope this information will help answer this important question that often arises during the execution of an applicable reroofing project. I won’t interpret the code – that’s your building official’s prerogative – but, at the end of the code path, the answer should be clear.
Mike Silvers, CPRC is owner of Silvers Systems Inc., and is consulting with FRSA as Director of Technical Services. Mike is an FRSA Past President, Life Member and Campanella Award recipient and brings over 45 years of industry knowledge and experience to FRSA’s team.
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