Subpart
1.
IBC section 1511.1.
IBC section 1511.1 is amended to read as follows:
1511.1
General. Materials and
methods of application used for recovering or replacing an existing roof
covering shall comply with the requirements of chapter 15.
Exception: Reroofing shall not be required to
meet the minimum design slope requirement of one-quarter unit vertical in 12
units horizontal (two percent slope) in Section 1507 for roofs that provide
positive drainage if all the following conditions are met:
1. The minimum required roof slope is
technically infeasible due to existing parapet heights, existing unalterable
flashing that requires positive drainage, or other obstacle.
2. The existing structure is demonstrated
through structural analysis to be capable of supporting ponding to the level of
the secondary emergency drainage system or point of overflow.
3. A secondary (emergency) drainage system is
installed in compliance with Section 1502.
Subp. 2.
IBC section 1511.5.
IBC section 1511.5 is amended to read as follows:
1511.5
Reinstallation of materials.
Existing slate, clay, or cement tile shall be permitted for
reinstallation, except that damaged, cracked, or broken slate or tile shall not
be reinstalled. Existing vent flashing, metal edging, drain outlets, collars,
and metal counterflashings shall not be reinstalled where rusted, damaged, or
deteriorated. Aggregate surfacing materials shall not be reinstalled unless
such aggregate complies with the gradation requirements of ASTM C-33 Standard
Specification for Concrete Aggregate.
Subp. 3.
IBC section 1511.7.
IBC section 1511 is amended by adding section 1511.7 to read
as follows:
1511.7
Drainage.
Existing roofs where the roof perimeter construction extends above the
roof in such a manner that water will be entrapped if the primary drains allow
buildup for any reason shall be equipped with a secondary (emergency) drainage
system.
Exception: Existing roofs that are demonstrated
to have the structural capacity to support the depth of ponding water where the
water will discharge over an exterior building edge if the primary drainage
system fails.
Notes
Minn. R. agency
151, ch. 1305, pt.
1305.1511
39
SR 1605;
44
SR 609 eff. 3/31/2020
