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Where is ice and water
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Complete 2007 Minnesota State Code
Roofing shall be
secured and fastened to the supporting roof construction and shall provide
weather protection for the building at the roof. Roofing products shall be
installed per the manufacture's installation instructions or Minnesota state
code requirement whichever is more restrictive. You can find manufactures
instructions on the back of shingle products packages or from the material
Underlayment & Ice and water
Entire state of Minnesota requires special eave protection
barrier that consists of
layers of Underlayment cemented together or of a self-adhering polymer
modifieded bitumen sheet, shall be used in lieu of normal Underlayment and
extend from the eave's edge to a point at least 24 inches (610 mm)
inside the exterior wall line of the building.
The code in Minnesota requires this special waterproof shingle
Underlayment at the eaves or lower edges of the roof.
Ice and Water Shield In Valleys:
Valleys shall have a 36-inch-wide
(914 mm) Underlayment of either one layer of Type I Underlayment running the
full length of the valley, in addition to other required Underlayment, or a
self-adhering polymer modified bitumen sheet complying with ASTM D 1970.
Ice and Water Shield Manufacture Recommendations:
Around all Penetrations, At the intersection of
walls, And intersection of Pitch changes.
Roofing Felt - Tar Paper:
The code requires
that Underlayment of one layer of non-perforated Type 15 felt lapped two inches
horizontally and four inches vertically to
R907.3 Re-covering versus replacement (reroofing
Hail exposure map has been revised.
Complete shingle and Underlayment tear-offs are required when reroofing in the
following Minnesota Counties (from Figure R903.5 Hail Exposure Map):
Le Sueur MN
Flashing Requirements: Existing flashings may be
re-used provided it has no holes and is serviceable. Under no circumstances may
(tar) or other asphalt material be used in lieu of metal flashing. (WE REPLACE
ALL ROOF FLASHINGS WITH NEW)
Flashing shall be
installed at the juncture of the roof and vertical surfaces. Flashing and
counter flashing shall be provided per roofing manufacture's instructions. Not
less than no 26 gage corrosion resistant metal shall be used.
Valley linings shall be installed in accordance with manufacturer's
installation instructions before applying shingles. Valley linings of the
types shall be permitted.
For open valley (valley lining exposed) lined with metal, the valley lining
shall be at least 24 inches wide and of any of the corrosion resistant metals
in Table R905.2.8.2. (no 26 gage
corrosion resistant metal)
For closed valleys (valley covered with shingles), use a valley lining of one
ply of smooth-roll roofing complying with ASTM D6380 Class S Type III, Class M
Type II or ASTM D3909 and at least 36 inches wide.
Step flashing shall be
installed into the masonry bed joints or adhered to the masonry. If the step
flashing is adhered, Counter flashing must be installed to cover the top edge
of the step flashing. This Counter flashing must be installed in either the
masonry bed joints or via a reglet cut into the masonry.
A cricket or saddle shall be installed on the ridge side of any
chimney greater than 30 inches (762 mm) wide. Cricket or saddle coverings
shall be sheet metal or the same material as the roof covering.
installed where the lower portion of a sloped roof stops within the plane of
an intersecting wall cladding, in such a manner as to divert or kick out water
away from the assembly.
flashing against a vertical-front wall and the soil stack, vent pipe and
chimney flashing, shall be applied according to
asphalt shingle manufacturer's printed instructions
Install strips of at least 1" by
4" nominal boards in the spaces.
(Overlay) the Existing roof Decking with
either lumber sheathing or wood
structural panel sheathing a minimum of 11/32" in thickness
Panel Or 1" Nominal. No edge of this material can be left
exposed to the weather; therefore, it must be metal edging or wood trim. (Open
To Interpretation By Building Official Regarding Overlay - State Code Does Not
The code requires that roof decks be solidly
sheathed for asphalt shingles or mineral surfaced roll roofing. Solid
sheathing may be plywood, OSB, or 1-inch nominal boards. When using 1-inch
nominal boards, the shingle manufacturers instructions should be reviewed to
determine if the manufacturer places any limitations on the use of their
shingles on a board sheathed roof. Wood shingles and shakes may be applied
over solid or spaced sheathing. When using spaced sheathing, sheathing boards
must be not less than 1X4’s and must be spaced on centers equal to the weather
exposure to coincide with the placement of fasteners. If the center-to-center
spacing of 1X4’s is 10 inches or more, additional 1X4’s must be installed
between the sheathing boards. The portion of the roof receiving ice protection
must be solidly sheathed. (R905)
Venting attic space:
Roof ventilation is required. Enclosed attics and enclosed rafter
spaces formed where ceilings are applied directly to the underside of the roof
rafters shall have cross ventilation for each separate space by ventilating
openings protected against the entrance of rain or snow. Ventilating openings
shall be provided with corrosion-resistant wire mesh, with 1/8 inch (3.2 mm)
minimum to 1/4 inch (6.35 mm) maximum openings. Minimum area: The total net-free
ventilating area shall not be less than 1:150 of the area of the space
ventilated exempt that the total area is permitted to be reduced to 1:300,
provided at least 50 percent and not more than 80 percent of the required
ventilating area is provided by ventilators located in the upper portion of the
space to be ventilated at least 3 feet (914 mm) above eave or cornice vents with
the balance of the required ventilation provided by eave or cornice vents. As an
alternative, the net free cross-ventilation area may be reduced to 1:300 when a
vapor barrier having a transmission rate not exceeding one perm (57.4
mg/s-m2-Pa) is installed on the warm side of the ceiling. It might be necessary
to add ventilation with your new roof to meet these standards. - If condensation
problems exist in the attic, they too will be revealed when the roof is torn
off. Properly designed attic ventilation can then be installed in order to help
eliminate such problems.
Above is part of the 2007 Minnesota State Code as
well as 2006 IRC and/or IBC . Certain cities and towns may have additional
requirements that may have to be met. Check with your local city hall.