Interpretation #7834
Published September 28, 2016
Original Request
- Code Version
- 2014
- Code
- BUILDING
- Code Description
- Chapter
- Section
- 1507.4.1
- Topic
- Metal roofing over existing
Question
Is it the intent of Section 1507.4.1 to not allow metal panels to be be installed over one layer of roof covering over solid decking when fastened to the deck per manufacturer installation requirements?
Answer Published 09/28/2016 at 9:45 PM
No. The section of the code noted is not the applicable
section for reroofing. Attaching an underlayment and metal
roof panels directly on existing asphalt shingles is not a
compliant installation. The example provided, is a
reroof/recover of an existing structure. Consequently, the
FBC, Existing Building is where one should begin to
establish the requirements for compliance. Section 708.3
Exception 2 of the FBC, EB addresses the issue of installing
metal roof systems over an existing roof covering. This
section requires the new metal roof system be completely
separate and designed to transmit the roof loads directly to
the buildings structural system. Additionally, the metal
roof cannot rely on the existing roof and roof coverings for
support. To accomplish this, a
batten/counterbatten or purlin system to which the metal
roofing system is secured, is a way to correctly transfer
the loads as required. Of course, no more than two roof
coverings may exist on a structure. Also see Informal
Interpretations #7415 and #7504.
section for reroofing. Attaching an underlayment and metal
roof panels directly on existing asphalt shingles is not a
compliant installation. The example provided, is a
reroof/recover of an existing structure. Consequently, the
FBC, Existing Building is where one should begin to
establish the requirements for compliance. Section 708.3
Exception 2 of the FBC, EB addresses the issue of installing
metal roof systems over an existing roof covering. This
section requires the new metal roof system be completely
separate and designed to transmit the roof loads directly to
the buildings structural system. Additionally, the metal
roof cannot rely on the existing roof and roof coverings for
support. To accomplish this, a
batten/counterbatten or purlin system to which the metal
roofing system is secured, is a way to correctly transfer
the loads as required. Of course, no more than two roof
coverings may exist on a structure. Also see Informal
Interpretations #7415 and #7504.
Commentary
None