Current through Register Vol. 35, No. 18, September 24, 2024
See this chapter of the IRC except as provided below.
A.
Section R903 Weather
Protection. See this section of the IRC except as provided below.
(1)
Section R903.2.1 Locations.
See this section of the IRC and the following to the end of the section:
Approved reglets or an approved flashing shall be installed at wall and roof
intersections, wherever there is a change in roof slope or direction and around
roof openings. Where flashing is of metal, the metal shall be corrosion
resistant with a thickness of not less than 0.019 inch (0.5 mm) (No. 26
galvanized sheet).
(2)
Section R903.3 Coping. Delete the text of this section and
substitute with the following: Plastered parapets shall require a seamless but
permeable waterproof cover or weather barrier, capping the entire parapet and
wrapping over each side. The cover shall extend past any break from the
vertical a minimum of four inches on the wall side. On the roof side, the cover
shall properly lap any rising roof felts or membranes and be properly sealed. A
layer of furred expanded metal lath shall be installed over the cover before
plaster or stucco is applied. The lath shall extend past any break from the
vertical on the wall side a minimum of five inches and on the roof side, the
same distance as the cover below, allowing for plaster stops or seals. No
penetrating fasteners are allowed on the horizontal surface of
parapets.
B.
Section R904 Materials. See this section of the IRC except add the
following new section: Section R904.5 Loose granular fill. Pumice
and other granular fill type materials are not permitted in roof
assemblies.
C.
Section R905
Requirements for Roof Coverings. See this section of the IRC except add
the following new sections.
(1)
Section
R905.9 Built-up roofs. See this section of the IRC except add the
following sections:
(a)
Section
R905.9.4 Roof deck transitions. Where roof sheathing is overlapped to
create drainage "crickets" or valleys to canales, taper board, or equivalent
shall be used to transition between the two deck levels to create a uniform
substrate.
(b)
Section
R905.9.5 Canales and scuppers. All canales and scuppers must have a
metal pan lining extending six inches minimum past the inside of the parapet
and six inches minimum to each side of the canale or scupper opening. All
canales or scuppers must have positive drainage.
(2)
Section R905.11 Modified bitumen
roofing. See this section of the IRC except add the following section:
Section R905.11.4 Roof deck transitions. Where roof sheathing is
overlapped to create drainage "cricket" or valleys to canales, taperboard or
equivalent shall be used to transition between the two deck levels to create a
uniform substrate.
(3)
Section R905.12 Thermoset single-ply roofing. See this section of
the IRC except add the following section: Section R905.12.4 Roof deck
transitions. Where roof sheathing is overlapped to create drainage
"crickets" or valleys to canales, taperboard or equivalent shall be used to
transition between the two deck levels to create a uniform substrate.
(4)
Section R905.13 Thermoplastic
single-ply roofing. See this section of the IRC except add the following
section: Section R905.13.4 Roof deck transitions. Where roof
sheathing is overlapped to create drainage "crickets" or valleys to canales,
taperboard or equivalent shall be used to transition between the two deck
levels to create a uniform substrate.
D.
Section R908 Reroofing. See
this section of the IRC except as provided below. Section R908.3 Roof
Replacement. Delete the text of this section and substitute with the
following: New roof coverings shall not be installed without first removing
existing roof coverings where any of the following conditions occur:
(1) The existing roof or roof covering is
water soaked or has deteriorated to the point that the existing roof or roof
covering is not adequate as a base for additional roofing.
(2) The existing roof covering is wood shake,
slate, clay, cement, or asbestos-cement tile.
(3) The existing roof has two or more
applications of any type of roof covering.
(4) Where pumice or other granular fill are
present, the material must be removed prior to installing a new
roof.