2011, 03-28 Permit App: 11000700 ReroofVaflIlcey.
Community Development Department
Permit Center
11703 East Sprague Avenue, Suite B-3
Spokane Valley, WA 99206
Tel: (509) 688-0036
Fax: (509) 688-0037
permitcenterCahspoka nevalley.orq
(Staff Use Only) t
PERMIT NUMBER:
PERMIT FEE:
REROOF CONSTRUCTION PERMIT APPLICATION
Q COMMERCIAL RESIDENTIAL
SITE ADDRESS: tloi 4, gi(e'S
ASSESSORS PARCEL NO.: LEGAL DESCRIPTION:
BUILDING OWNER NAME'
NAME:
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ADDRESS: Z6,
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PHONE: / (1 09 5n
CITY:
FAX:
CONTACT NAME: ..Sen
STATE: bo4
Zv5- 906S
CELL:
PHONE: FAX:
CELL:
CONTRACTOR NAME: 7 ,4(4v4.� Li'
MAILING ADDRESS:: ` 3 -P-a c � cu.107{� 74 -j/
CITY: h ��/ STATE: 4 `I
PHONE: 99 3e> [9+/ ,�' ,� l FAX: Zef / /r /V fj > CELL:
CONTRACTOR LICENSE NO.: //k414�y1m(kXPIRES: 7 (i i / 1 / CITY BUSINESS LICENSE NO.:
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ZIP:9/ &xc..
DESCCRIBBET SCOPE OF WORK INDr AIL AND INDICATE USE:
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TOTAL COST OF PROJECT: $
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DISCLAIMER
The permitted verifies, acknowledges and agrees by their signature that: 1) if this permit is for construction or on a dwelling, the dwelling Is/will
be served by potable water. 2) Ownership of this City of Spokane Valley permit inure to the property owner. 3) The signatory Is the property
owner or has permission to represent the property owner in this transaction. 4) All construction is to be done in full compliance with the City of
Spokane Valley Development code. Referenced codes are available for review at the City of Spokane Valley Permit Center. 5) The City of
Spokane Valley permit Is not a permit or approval for any violation of federal, state or local laws, codes or ordinances. 6) Plans or additional
information may be required to be submitted and subsequently approved before this application can be processed.
Signature
Date:
014///
Updated 1-11-11 Page 1 of 1
http://www.spokanevalley.org/filestorage/124/938/210/948/1496/Reroof_Permit_1-11-11.doc
SECTION R907
REROOFING
R907.1 General. Materials and methods of application used
for re-covering or replacing an existing roof covering shall
comply with the requirements of Chapter 9.
Exception: Reroofing shall not be required to meet the min-
imum design slope requirement of one-quarter unit vertical
in 12 units horizontal (2 -percent slope) in Section R905 for
roofs that provide positive roof drainage.
+This section addresses the concerns associated with
unregulated reroofing operations. The provisions re-
quire that when an existing building is reroofed, the ex-
isting roof be structurally sound and in a proper condi-
tion to receive the new roofing. It is often necessary to
remove the existing roof covering prior to installing the
new roofing materials. This section identifies those sit-
uations where the reroofing cannot occur over an ex-
isting roof covering.
If new roof covering materials are to be installed as a
replacement for an existing roof covering, or if the new
roof covering is applied directly over an existing roof,
the roof covering materials and the application pro-
cess must conform to the provisions for a new roof
covering installation.
There may be occasions where only a small portion
of the existing roof covering is in need of replacement
or a limited amount of the roof is in need of repair. In
those situations, it is acceptable to use the provisions
for existing buildings in Chapter 34 of the IBC particu-
larly Section 3401.4. This section of the IBC permits
the alteration or repair of nonstructural elements using
the same materials that are already in place. In other
words, the repair or replacement of existing roof cover-
ing may be made using the same materials and meth-
ods found on the existing roof. It is assumed that the
repairs will not cause the building to be reduced in
code compliance from the previous level.
R907.2 Structural and construction loads. The structural
roof components shall be capable of supporting the roof cover-
ing system and the material and equipment loads that will be
encountered during installation of the roof covering system.
+ A fundamental requirement throughout the code is the
recognition of the impact of any new repair or replace-
ment work on the structural system. If a new roof cov-
ering system is installed, the structural members of the
roof and any additional structural members that carry
roof loads must be reviewed for their ability to support
the loads that will be imposed during the installation
process. This includes the weight of the new roof cov-
ering materials as well as any installation equipment
that is placed on the roof.
R907.3 coverm versus:replacement:New roof coverings
shall not a insta ed without first removing all existing layers
of roof coverings where any of the following conditions exist:
1. W,herethe-existingroofioraoo ovenngas,ovate sc naked
urrhasaterioratedsto;theipoint that.tttetexisting>ioof•-or
0o covering;is not:adequate:as•a:basetforaadditional
u�ofing.
ROOF ASSEMBLIES
2. Where the existing roof covering is wood shake, slate,
clay, cement or asbestos -cement tile.
3. Where the existing roof has two or more applications of
any type of roof covering.
4. For asphalt shingles, when the building is located in an
area subject to moderate or severe hail exposure accord-
ing to Figure R903.5.
Exceptions:
1. Complete and separate roofing systems, such as
standing -seam metal roof systems, that are designed
to transmit the roof loads directly to the building's
structural system and that do not rely on existing roofs
and roof coverings for support, shall not require the
removal of existing roof coverings.
2. Installation of metal panel, metal shingle and concrete
and clay tile roof coverings over existing wood shake
roofs shall be permitted when the application is in
accordance with Section R907.4.
3. The application of new protective coating over exist-
ing spray polyurethane foam roofing systems shall be
permitted without tear -off of existing roof coverings.
❖ The base for application of new roofing materials must
provide a sound and consistent surface on which to in-
stall the new materials. The code will not permit the in-
stallation of new roof coverings over existing roof cov-
erings where there is a potential for future problems
with the roof's effectiveness. Therefore, the code lists
four specific conditions where all existing layers of the
roof covering materials must be removed prior to the
installation of new roofing.
Ifith erexistingrroofzonroofzcoveringzistwate rrsoaked,
the concealwent.of,ttie existing reofrinisuchtalcoridition
wi eel .addorpreblemsrof deteriorationtandtfailure intthe-
fubIre..Atxasituatinntwhereithetexisting oof;construcd,
tioncdeastnottprovidetforatuacceptatil eiba"satereaso n
tegemoye:alltexistingxrgofzcove ringtmaterials c pri orsto
reroofing. In addition, roofing materials such as wood
shakes, clay tiles and similar materials are not gener-
ally acceptable as a base for a new roof covering be-
cause of the variation in their surfaces. Exception 2
permits the installation of a new roof covering over
wood shakes or shingle roofs only if the surface below
the new roofing is properly protected in accordance
with Section R907.4.
A maximum of two roof coverings is permitted by the
code, based primarily on the dead load weight that is
accumulated on the roof for every layer of roofing ma-
terials. Where two or more applications of any roof
covering are present, the existing materials must be
removed prior to installation of the new roof covering.
Asphalt shingles present a special concern in those ar-
eas likely to have hail. Where moderate or severe hail
damage can be expected, based on the map shown in
Figure R903.5, it is always necessary to remove an ex-
isting asphalt shingle roof covering prior to the applica-
tion of any new roof covering (see commentary, Sec-
tion R903.5).
2009 INTERNATIONAL RESIDENTIAL CODE® COMMENTARY 9-35
Wand
`' ordnvest
IBOQInccrioq. Inc.
Tamarack Ridge Construction
Jon D. Hawley
3622 South Sundland
Spokane Valley, WA 99206
Tapio Office Center. Green Flag Building
" 104 South Freya Street, Suite 110-F
.1 Spokane, WA 99202.'
(509) 532-1532 Voice
" (509) 534-0664 Fax
March 23, 2011
RE: Hainline Roof Study, 2609 South Bates Road, Spokane Valley, Washington
Project Number. 2010135 Hainline Roof Study
Dear Jon Hawley,
We have reviewed the construction and condition of the above referenced structure. The split
level single family residence consists of conventionally framed rafters sloped 4 to 12,
conventionally framed floor joists and continuous concrete foundation walls.
The roof framing is 2x6 rafters at 2'-0" on center spanning up to 10'-0" from the exterior walls to
2x6 ridges, 2x6 hips and 2x4 purlins braced to load bearing walls at 4'-0" on center. The sizes of
the roof structure elements indicate that a combined roof dead load and snow load of
approximately 47 pounds per square foot was used for design. This would allow for a total
roofing weight of at least 9 pounds per square foot which is equivalent to 1 1/2" of asphalt or tar
or three layers of asphalt or composition shingles The existing roofing is two layers of asphalt
shingles allowing reroofing of the structure with one additional layer of roofing of a similar weight.
The reason for proposed reroofing is deterioration of the wearing surface of the roofing due to
environmental conditions. There is not evidence of deterioration of the roof deck and the existing
roofing is not water -soaked and with normal preparation will serve as an adequate base for
additional roofing.
We have reviewed the proscription against application of a third layer of roofing with respect to
this proposed application. Section R907.3 of the International Residential Code requires removal
of existing roofing where the existing roof or roofing is water -soaked or inadequate as a base for
additional roofing, the existing roofing is wood shake, slate, clay, cement or asbestos -cement tile
or there are two or more layers of existing roofing. The exceptions provided for this rule indicate
that this restriction need not apply where the ability of the roof decking to provide continuous
support for the roofing is not in question. This indicates that, where two layers of previous roofing
have failed, it is likely to be the result of inadequate decking or structural stiffness. This is often
the case when: the existing rafters are undersized, the existing decking is shiplap or oriented long
dimension parallel to rafters or sheathing has an inadequate span rating.
Our calculations indicate that the rafters are adequately sized and deflections are well below
limits that would affect roofing performance. The existing roof sheathing is 1/2" plywood installed
long dimension perpendicular to supports with staggered seams and a 32/16 span rating.
Since the supporting structure is adequate to support the additional weight of another layer of
roofing, roofing nails with adequate length to achieve the required penetration of the sheathing
are to be used and upon completion of installation the new roofing would only be subject to the
same live load deflections as with the existing roofing removed, we feel that the roofing material
will be unaffected by the additional layer of existing roofing. We have contacted the roofing
manufacturer to confirm that their warranty will not be affected by application over the two existing
layers of roofing in this case.
The existing roof surface must be prepared as recommended by the manufacturer to eliminate
high spots, low spots and foreign debris. The third layer of roofing must be secured with 6d
(0.099" diameter) x 1 %" roofing nails for full penetration through all roofing layers and roof
sheathing. These nails must be installed in each shingle at locations as specified by the roofing
manufacturer and spaced at not less than 1.5 nails per square foot of exposed shingle surface
within 3'-0" of any roof edge and 0.67 nails per square foot of exposed shingle surface at interior
areas. Structural observation will be required at the completion of the project.
If you have any questions or need any additional information, please call.
Sincerely,
Brett Danielson, P. E.
Inland Northwest Engineering Incorporated
enclosure
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