Section 706.7.2 of the FBC Existing Building Code notes that for HVHZ reroof projects, a secondary water barrier is required by use of 4-6" SA stripping over the plywood deck joints and a 30# felt is required atop that. It also notes that "No additional underlayment shall be required over the top of this [30#] sheet). Note this does not apply to roof slopes < 2:12 or clay/concrete tile roofs. Could you please help explain what this means and what will be required for steep-slope reroofs (non-tile)? Is the 30# felt considered a "water barrier"? And therefore, once the joints are stripped in and the 30# is applied, another water barrier (continuous SA mod bit sheet) would not also be required? Please also confirm that the stripping is not required for the non-HVHZ zones, and that for reroofs and new construction, just a single layer of SA mod bit can be applied direct to the deck? Thank you!
Kelsey McMenamy
Section 706.7.2 of the FBC Existing Building Code notes that for HVHZ reroof projects, a secondary water barrier is required by use of 4-6" SA stripping over the plywood deck joints and a 30# felt is required atop that. It also notes that "No additional underlayment shall be required over the top of this [30#] sheet). Note this does not apply to roof slopes < 2:12 or clay/concrete tile roofs. Could you please help explain what this means and what will be required for steep-slope reroofs (non-tile)? Is the 30# felt considered a "water barrier"? And therefore, once the joints are stripped in and the 30# is applied, another water barrier (continuous SA mod bit sheet) would not also be required? Please also confirm that the stripping is not required for the non-HVHZ zones, and that for reroofs and new construction, just a single layer of SA mod bit can be applied direct to the deck? Thank you!