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Reference Document |
Comments Received |
Staff Position |
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101 Retrofits Required. Pursuant to Section 553.884, |
FRSA The reference in the proposed rule to “section 553.884” should be “section 553.844” to be correct. |
Agree, recommend approval. |
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101.1
When a roof on an existing site-built, single
family residential structure is replaced: (a) Roof-decking
attachment and fasteners shall be strengthened and corrected as required by
section 201.1. (b) A
secondary water barrier shall be provided as required by section 201.2. |
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101.2
When a roof is replaced on a building that is
located in the wind-borne debris region as defined in s. 1609.2 of the (a)
Roof to wall connections shall be improved
as required by section 201.3. (b)
Mandated retrofits of the roof-to-wall connection
shall not be required beyond a 15 percent increase in the cost of re-roofing. (c) Where complete retrofits of all the roof-to-wall connections as prescribed in Section 201.3 would exceed 15 percent of the cost of the re-roofing project, the priorities outlined in Section 201.3.5 shall be used to limit the scope of work to the 15 percent limit. |
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101.3 When
any activity requiring a building permit that is applied for on or after July
1, 2008, and for which the estimated cost is $50,000 or more for a building
that is located in the wind borne debris region as defined in s. 1609.2 of
the (a)
Opening protections as required within the |
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101.4 When retrofit enhancement of gable end bracing is provided during construction which otherwise requires a permit the techniques in Appendix A shall be allowed. |
Ray Burroughs Section 101.4, if gable
end bracing is voluntary as you indicated, this section needs to better indicate
such. As written the retrofit is
required as a part of a project involving
"construction which otherwise requires a permit". Thus if
they are doing any type of activity requiring a permit it would trigger gable
wind bracing for example replacing their air conditioner, replacing their
elect panel, etc. |
Needs discussion and consideration |
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Mike Moore Adding a new section: 101.5 When
a home inspector inspects an existing home as part of a real estate
transaction and determines that the roof decking attachment does not meet the
requirements of Section 201.1, adhesives shall be used to strengthen the
decking attachment per Section 201.2, unless the roof is being replaced per
Section 101.1. |
Needs discussion and consideration. |
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201
Roof System Mitigation
Techniques. Roof
sheathing fastening, secondary water barriers, roof to wall connection and
gable end bracing shall be permitted pursuant to this section. |
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201.1 Roof
sheathing fastening for site-built
single family residential structures. For site-built single family
residential structures the fasteners
and spacing required in Table 201.1 are deemed to comply with the
requirements of Section 511.5, Board roof
decking secured with at least two 8d nails into roof framing members shall be
deemed to be sufficiently connected.
Board roof decking secured with smaller fasteners than 8d nails or
with fewer than two 8d nails per board shall be deemed sufficiently connected
if two 8d clipped head, round head, or ring shank nails are in place on each
framing member. Supplemental fasteners as required by Table 201.1 shall be 8d
ring shank nails with round heads and the following minimum dimensions: 1. 0.113 inch nominal shank diameter 2. Ring diameter of 0.012 over shank diameter 3. 16 to 20 rings per inch 4. 0.280 inch full round head diameter 5. 2-1/4 inch nail length |
Ray Burroughs Section 201.1, in the
last line it should reference the Existing Building Code not the Building
Code. FRSA Replace language with the following: 201.1 Roof sheathing fastening for site-built single
family residential structures. Roof
sheathing shall be fastened to meet the requirements of chapters 16 and 23 of
the Add the following to chapter 15: 1510.1.1 Roof sheathing shall be fastened to meet the
requirements of chapter 16 and 23 of the Mike Moore 201.1 Roof sheathing
fastening for site-built single family residential structures during
re-roofing. For site-built single family residential
structures the fasteners and spacing required in Table 201.1 are deemed to
comply with the requirements of Section 511.5, General Comment: CW Macomber Nail length needs
consistency with the code. Residential
requires 8d ring shank .113; Building requires notes 1-5, 8d nails per board,
etc. |
Ray Burroughs comment is editorial and recommend approval. FRSA, need discussion and consideration. Mike Moore, the use of the word reproofing is not consistent with language of the law. |
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Mike Moore Adding a new section: 201.2 Roof
sheathing fastening for site-built single family residential structures prior
to re-roofing. When a home
inspection completed for a real estate transaction reveals that the roof
decking attachment does not meet the fastener requirements of Table 201.1,
and when this roof will not be re-roofed at the time of the transaction, an
AFG-01 approved adhesive shall be applied in a 1/4" bead to the
90-degree joint between the underside of the roof decking and the supporting
roof framing to strengthen this connection. General Comment: Bill York: existing column, foam
adhesives used to increase strength, life tests done, should not be required
to renail. Tim
Reinholt, how will it hold up in the long term in a hot environment? Billy
Cone, foam works when you can walk around the attic, reroofing or recovering? Robert
Bullard, benefit of peel and stick tends to bond edges of butting layers
together, adhesive layer better than conventional, should enhance warranties
being issued. |
Needs discussion and consideration. |
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Table 201.1 Supplement Fasteners at Panel Edges and
Intermediate Framing
a. Maximum spacing determined based on
existing fasteners and supplemental fasteners. b. Maximum spacing determined based on
supplemental fasteners only. |
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201.2 Roof secondary water barrier for site-built
single family residential structures. A secondary water barrier shall be
installed using one of the following methods when roofing replacement when
reroofing. a) All joints in roof
sheathing or decking shall be covered with a minimum 4 in. wide strip of
self-adhering polymer modified bitumen tape applied directly to the sheathing
or decking. The deck and self adhering
polymer modified bitumen tape shall be covered with one of the underlayment
systems approved for the particular roof covering to be applied to the roof. b) The entire roof deck
shall be covered with an approved self-adhering polymer modified bitumen cap
sheet. No additional underlayment
shall be required on top of this cap sheet for new installations. EXCEPTIONS: 1.
An asphalt impregnated 30# felt underlayment
installed with nails and tin-tabs as required for the HVHZ and covered with
either an approved self-adhering polymer modified bitumen cap sheet or an
approved cap sheet applied using an approved hot-mop application shall be
deemed to meet the requirements for the secondary water barrier. |
Bill Dumbaugh 201.2 Secondary water barrier for site built
single family residential structures. A secondary water barrier shall be
installed using one of the following methods when roofing replacement when
reproofing.
EXCEPTIONS: 1. In lieu of 1 and 2 above,
buildings and structures located in HVHZ with nailable decks shall be
installed in accordance with section 1518,
and 1519, which shall be deemed
to meet the requirements of a
secondary water barrier
2. A
roof deck that is sufficiently fastened as prescribed in Section 201.1 and
provided with a secondary water barrier as outlined above shall be deemed to
meet the requirements of this section. Chris Schulte Mo, I modified the comment proposed by Bill Dumbaugh as was provided at the Mitigation Workshop...Strikes & underlines are adds/deletions to his original document...There are 2 different options...figured we could discuss whether to allow peel & stick at the plywood joints with the HVHZ folks... General Comment: Bill
Dumbaugh, base sheet in HVHZ is equivalent, is for reroof only, should be
acceptable as a secondary water barrier. CW
Macomber for APA, strike as required for HVHZ, does not apply to the rest of
the state. Not code language, cap sheet should say underlayment. Robert Bullard General information regarding the use of custom latex elastomeric coating material to anchor existing asphalt shingle roofs against high wind. FRSA Proposed language: 201.2 Roof secondary water barrier for site-built
single family residential structures. A secondary water barrier shall be
installed using one of the following methods a) All joints in roof
sheathing or decking shall be covered with a minimum 4 in. wide strip of adhered approved membrane b) The entire roof deck
shall be covered with an approved adhered
membrane c) The
entire roof deck shall be covered with a mechanically attached approved
membrane. d) All
joints in the roof sheathing shall be sealed with an approved sealant. e) All joints in the roof sheathing shall be
sealed with an approved sealant; the entire roof shall then be covered with
an approved coating.
General
Comment: Jack
Glenn, for Loraine Ross, keep options, current requirements, attic space must
be ventilated. Billy
Cone, HVHZ has specific requirements for ventilation. If new roof is breached, joints need to
minimize water intrusion, should have rain driven test and rain uplift test,
only required for reroofing. No
difference between the two roofs. What
is purpose? If breached, exposed wood,
nothing keeps water from going inside, seal joints of plywood. Submitted code change for wind driven rain
and wind uplift, doesn’t have to be peel and stick. How many nails will ruin that board. Can seal with caulking, utilize multiple
methods. Chris
Schulte, underlying premise that the roof will fail. Bigger code issue if preparing for
failure. Def for water barrier? Do we have a secondary water barrier? |
Bill Dumbaugh, needs discussion and consideration. Chris Schulte, need discussion and consideration. Robert Bullard, needs discussion and consideration. FRSA, needs discussion and consideration. |
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201.3 Roof-to-wall connections for site-built single family
residential structures. Where required by Section
511.4, the intersection of roof framing with the wall below shall be
strengthened by adding metal connectors, clips, straps, and fasteners such
that the performance level equals or exceeds the uplift capacities as
specified in Table 201.3. As an
alternative to an engineered design, the prescriptive retrofit solutions
provided in Sections 201.3.1 through 201.3.4 shall be accepted as meeting the
mandated roof-to-wall retrofit requirements. |
Ray Burroughs Section 201.3, second line should clarify 511.4 is in the Existing Building Code. FRSA |
Ray Burroughs, editorial comment, recommend approval. |
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201.3.1 Prescriptive method for gable roofs
on a wood frame wall. Sufficient eave sheathing shall be removed
to expose a minimum of 6-feet of framing members, measured from the corner,
along the exterior wall on each side of each gable end. The anchorage of each of the exposed rafters
or truss shall be inspected. Wherever
a strap is missing or an existing strap has fewer than four fasteners on each
end, approved straps, ties or right angle gusset brackets with a minimum
uplift capacity of 500 lbs shall be installed that connect each rafter or
truss to the top plate below. Adding
fasteners to existing straps shall be allowed in lieu of adding a new strap
provided the strap is manufactured to accommodate at least 4 fasteners at
each end. Wherever access makes it
possible (without damage of the wall or soffit finishes), both top plate
members shall be connected to the stud below using a stud to plate connector
with a minimum uplift capacity of 500 lbs. |
FRSA |
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201.3.2 Prescriptive method for gable roofs
on a masonry wall. Sufficient eave sheathing shall be removed
to expose a minimum of 6-feet of framing members, measured from the corner,
along the exterior wall on each side of each gable end. The anchorage of each of the exposed rafters
or truss shall be inspected. Wherever
a strap is missing or an existing strap has fewer than four fasteners on each
end, approved straps, ties or right angle gusset brackets with a minimum
uplift capacity of 500 lbs shall be installed that connect each rafter or
truss to the top plate below or directly to the masonry wall using approved
masonry screws that will provide at least a 2-1/2 embedment into the concrete
or masonry. When the straps or right
angle gusset brackets are attached to a wood sill plate, the sill plate shall
be anchored to the concrete masonry wall below. This anchorage shall be accomplished by
installing ¼-inch diameter masonry screws, each with supplementary ¼-inch
washer, having sufficient length to develop a 2-1/2 inch embedment into the
concrete and masonry. These screws
shall be installed within 4-inches of the truss or rafter on both sides of
each interior rafter or truss and on the accessible wall side of the gable
end truss or rafter. |
FRSA |
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201.3.3 Prescriptive method for hip roofs
on a wood frame wall. Sufficient corner eave sheathing shall be
removed from the side of the hip ridge parallel to the roof ridge to provide
access to a minimum 6-foot length of the exterior wall. The hip ridge board and any exposed rafters
that are not anchored with a strap having at least four fasteners on each
end, shall be connected to the top plate below using a strap or a right angle
gusset bracket having a minimum uplift capacity of 500 lbs. Adding fasteners to existing straps shall
be allowed in lieu of adding a new strap provided the strap is manufactured
to accommodate at least 4 fasteners at each end. Wherever access makes it possible (without
damage of the wall or soffit finishes), both top plate members shall be
connected to the stud below using a stud to plate connector with a minimum
uplift capacity of 500 lbs. |
FRSA |
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201.3.4 Prescriptive method for hip roofs
on a masonry wall. Sufficient corner eave sheathing shall be
removed from the side of the hip ridge parallel to the roof ridge to provide
access to a minimum 6-foot length of the exterior wall. The hip ridge board and any exposed rafters
that are not anchored with a strap having at least four fasteners on each
end, shall be connected to the concrete masonry wall below using approved
straps or right angle gusset brackets with a minimum uplift capacity of 500
lbs. Adding fasteners to existing straps
shall be allowed in lieu of adding a new strap provided the strap is
manufactured to accommodate at least 4 fasteners at each end. The straps or right angle gusset brackets
shall be installed such that they connect each rafter or truss to the top
plate below or directly to the masonry wall using approved masonry screws
that will provide at least a 2-1/2 embedment into the concrete or
masonry. When the straps or right
angle gusset brackets are attached to a wood sill plate, the sill plate shall
be anchored to the concrete masonry wall below. This anchorage shall be accomplished by
installing ¼-inch diameter masonry screws, each with supplementary ¼-inch
washer, with sufficient length to develop a 2-1/2 inch embedment into the
concrete and masonry. These screws
shall be installed within 4-inches of the truss or rafter on both sides of
each interior rafter or truss and on the accessible wall side of the gable
end truss or rafter. |
FRSA |
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201.3.5 Priorities for mandated
roof-to-wall retrofit expenditures. For houses with both hip and
gable roof ends, the priority shall be to retrofit the gable end roof-to-wall
connections unless the width of the hip end is more than 1.5 times greater
than the width of the gable end.
Priority shall be given to connecting the corners of roofs to walls
below where the spans of the roofing members are greatest. |
FRSA |
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Table
201.3 Required Uplift Capacities for Roof-to-Wall
Connections (POUNDS PER LINEAR FOOT)
Notes: a. The required capacities are pounds per
lineal foot of building length. For
roof framing spaced at 16 inches on center multiply table values by 1.33. For roof framing spaced at 24 inches on
center multiply table values by 2. b. The required capacities include an
allowance for 10 pounds of dead load. c. The required capacities do not account for
the effects of overhangs. The overhang
loads given shall be multiplied by the overhang projection and added to the
required capacities in the table. |
Ray Burroughs Table 201.3, last column headered "overhangs", is this for all overhang projections, obviously a 12 inch overhang has less uplift than a 24 inch overhang. |
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APPENDIX A GABLE END WALL BRACING RETROFIT SECTION A101 GENERAL A101.1 Intent and purpose. The provisions of this subsection provide prescriptive solutions for
the retrofitting of gable ends of buildings. The retrofit measures are not
intended to provide strengthening of buildings equal to the structural
provisions of the latest building code requirements for new buildings. Design for compliance of new buildings and
additions to existing buildings shall conform to the requirements of the A101.2 Scope.
The
following prescriptive methods are intended for applications where the gable
end wall framing is provided by a wood gable end wall truss or a
conventionally framed rafter system.
The retrofits are appropriate for wall studs oriented with their broad
face parallel to or perpendicular to the gable wall surface. An overview perspective drawing of the
retrofit is shown in Figure A104.1. |
General Comments; Jack Glenn, building official can not allow use of appendix. Chris Schulte, 104.3.2, could not find figure detail in drawing.
105.1, single retrofit stud assembly?
104.6.1 screws, nails, bolts, what is 4 1/2/” long? Retrofit not intended to provide Richard Reynolds, wrote document, changed 12 sections. Mo, make specific comments in writing. CW Macomber, 350# 500 lb, A104, straps and tie plates, should be
metal plate connectors, 8d nails are larger, cant use straps that have 16d
hole sizes, manufacturers do not allow flat strap twisted in the field. What
are the figures and tables? Do all
fasteners have to be screws? 1 ¼ or 2
¼ inch fasteners? .31 or .13? can’t buy 8 wood screws. What is a hurricane fastener? Hard to figure out where the strap goes on
the figure, how attaches? Bent flat
strap? Where is the strap? Duplicate, confusing notes on the figures. Add diameter to fastener, page 32. Page 36, refers to wrong section
number. Table, page 21, add wind
speeds (no 100 in |
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SECTION A102 DEFINITIONS ANCHOR
BLOCK. A nominal 2-inch thick by at least 4” wide piece of lumber
secured to horizontal braces and filling the gap between existing framing
members for the purpose of restraining horizontal braces from movement
perpendicular to the framing members. COMPRESSION
BLOCK. A nominal 2-inch thick
by at least 4” wide piece of lumber used to restrain in the
compression mode (force directed towards the interior of the attic) an
existing or retrofit stud. It is
attached to a horizontal brace and bears directly against the existing or
retrofit stud. CONVENTIONALLY
FRAMED GABLE END. A conventionally framed gable end with
studs whose faces are perpendicular to the gable end wall. HORIZONTAL
BRACE. A nominal 2-inch thick
by at least 4” wide piece of lumber used to restrain both compression
and tension loads applied by a retrofit stud.
It is typically installed horizontally on the top of floor framing
members (truss bottom chords or ceiling joists) or on the bottom of pitched
roof framing members (truss top chord or rafters). RETROFIT
STUD. A nominal 2-inch lumber member used to
structurally supplement an existing gable end wall stud. RIGHT ANGLE GUSSET BRACKET. A
14 gage or thicker metal right angle bracket with a minimum load capacity
perpendicular to the plane of either face of 350 lbs when connected to wood
or concrete with manufacturer specified connectors. STUD-TO-PLATE CONNECTOR. A manufactured
metal connector designed to connect studs to plates with a minimum uplift
capacity of 500 lbs. TRUSS GABLE
END. An engineered factory made truss or site
built truss that incorporates factory installed or field installed vertical
studs with their faces parallel to the plane of the truss and are spaced no
greater than 24-inches on center. Web
or other diagonal members other than top chords may or may not be
present. Gable end trusses may be of
the same height as nearby trusses or may be drop chord trusses in which the
top chord of the truss is lower by the depth of the top chord or outlookers. |
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SECTION A103 MATERIALS OF CONSTRUCTION A103.1 Existing materials. All existing wood materials
that will be part of the retrofitting work (trusses, rafters, ceiling joists,
top plates, wall studs, etc.) shall be in sound condition and free from
defects or damage that substantially reduce the load-carrying capacity of the
member. Any wood materials found to be
damaged or deteriorated shall be strengthened or replaced with new materials
to provide a net dimension of sound wood equivalent to its undamaged original
dimensions. |
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A103.2
New Materials. All materials approved by
this code, including their appropriate allowable stresses, shall be permitted
to meet the requirements of this chapter. A103.3 Dimensional Lumber. All dimensional lumber for braces, studs,
and blocking shall conform to applicable standards or grading rules. Dimensional lumber shall be identified by a
grade mark of a lumber grading or inspection agency that has been approved by
an accreditation body that complies with DOC PS 20. All new dimensional lumber to be used for
retrofitting purposes shall be a minimum grade and species of #2 Spruce-Pine-Fir
or shall have a specific gravity of 0.42 or greater. In lieu of a grade mark, a certificate of
inspection issued by a lumber grading or inspection agency meeting the
requirements of this code shall be accepted. A103.4 Metal Plate
Connectors, Straps and Anchors. Metal
plate connectors, straps and anchors shall have product approval. They shall be approved for connecting
wood-to-wood or wood-to-concrete as appropriate. Straps and tie plates shall be manufactured from galvanized steel with
a minimum thickness provided by 20 gauge.
Tie plates shall have holes sized for 8d nails. |
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A103.5
Twists in straps. Straps
shall be permitted to be twisted 90 degrees in addition to a 90 degree bend
where they transition between framing members or connection points. A103.6 Fasteners. Fasteners meeting
the requirements of Sections A103.6.1 and A103.6.2 shall be used and shall be
permitted to be screws or nails meeting the minimum length requirement shown
in figures and specified in tables. A103.6.1
Screws. Screws shall be a minimum #8
size with head
diameters no less than 0.3 inch.
Screw lengths shall be no less than indicated in the Figures and in
Tables. Permissible screws include deck screws, wood screws, or sheet
metal screws (without drill bit type tip, but can be sharp pointed). Screws shall have at least 1 inch of
thread. Fine threaded screws or
drywall screws shall not be permitted.
Note that many straps will not accommodate screws larger than #8.
A103.6.2 Nails. Unless otherwise indicated in the
provisions or drawings, where fastener lengths are indicated in Figures and Tables as 1-¼ inch, 8d common nails with shank diameter 0.131 inch and head
diameters no less than 0.3 inch shall be permitted. Unless otherwise indicated in the
provisions or drawings, where fasteners lengths are indicated in Figures
and Tables as 3 inch, 10d common
nails with shank diameter of 0.148 inch and head diameters no less than 0.3
inch shall be permitted. |
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A103.7 Fastener
spacing. Fastener spacing shall be as
follows: a) distance between fasteners and the edge of lumber
shall be a minimum of ½ inch unless otherwise indicated, b) distance between fasteners and the end of lumber shall be a minimum
of 2-½ inch, c) distance between fasteners
parallel to grain (center-to-center) when straps are not used shall be a
minimum of 2-1/2 inches unless a ½-inch stagger (perpendicular to the grain)
is applied for adjacent fasteners, then the distance between fasteners
parallel to the grain shall be a minimum of 1-1/4 inches. d). distance between fasteners across grain (row spacing) when straps
are not used shall be a minimum of 1 inch, and the e) distance between fasteners inserted in metal plate connectors,
straps and anchors as defined in Section A103.4 shall be those provided by
holes manufactured into the straps. |
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SECTION A104 RETROFITTING GABLE END WALLS A104.1 Scope and intent.
Gable ends to be strengthened shall be permitted to be retrofitted
using methods prescribed by provisions of this section. These prescriptive methods of retrofitting
are intended to increase the resistance of existing gable end wall
construction for out-of-plane wind loads resulting from high wind
events. The retrofit method addresses
four issues. These include
strengthening the framing members of the walls if necessary (retrofit studs),
bracing the top and bottom of the gable wall so that lateral loads are
transmitted into the roof and ceiling diaphragms (horizontal braces, straps
to retrofit studs and compression blocks) and connecting the bottom of the
gable end wall to the wall below to help brace the top of that wall
(specialty metal brackets). The following prescriptive methods are intended for applications
where the gable end wall framing is provided by a wood gable end wall truss
or a conventionally framed rafter system.
The retrofits are appropriate for wall studs oriented with their broad
face parallel to or perpendicular to the gable wall surface. An overview perspective drawing of the
retrofit is shown in Figure A104.1. |
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A104.2 Horizontal Braces. Horizontal braces shall be installed
approximately perpendicular to the top and bottom chords of the existing roof
trusses or approximately perpendicular to the rafters and ceiling joists at
the location of each existing gable end wall stud greater than 3-feet in length. If the spacing of existing gable end studs
is greater than 24 inches or no vertical gable end stud is present, a stud
and horizontal braces shall be installed such that the maximum spacing
between existing and added studs shall be 24–inches. Additional gable end wall studs shall not
be required at locations where their length would be 3-feet or less. Each required added stud shall be attached
to the existing roofing framing members (truss top chord or rafter and truss
bottom chord or ceiling joist) using a minimum of two 3-inch toenail
fasteners (#8 wood screws or 10d nails) and a metal connector or mending
plate with a minimum of four 1-1/4 inch long fasteners (#8 wood screws or 8d
nails) at each end. The horizontal
braces shall consist of the minimum size member indicated in Table
A104.2. The horizontal brace shall be
oriented with their long face across the top and bottom chords of the wood
trusses (or rafters and ceiling joists) and extend a minimum of three framing
spacings from the gable end wall plus 2-1/2 inch beyond the last top chord or
bottom chord member (rafter or ceiling joist) as shown in Figure A104.2.1
(and A104.2.6). The horizontal brace
shall be located no farther than 1/2 inch from the
inside face of the gable end wall truss. Each horizontal brace shall be fastened to
each existing framing member (top chord or rafter or bottom chord or ceiling
joist) that it crosses using three 3-inch long fasteners (#8 wood screws or
10d nails) as indicated in Figures A104.2.2 through A104.2.5 for trusses (and
Figures A104.2.7 through A104.2.10 for rafters). |
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Exceptions: 1.
Where
obstructions, other permanently attached obstacles or conditions exist that
will not permit installation of new horizontal braces at the indicated
locations, refer to Section A104.5 for permitted modification of these
prescriptive retrofit methods. 2.
Where
obstructions, other permanently attached obstacles or conditions exist that
will not permit extension of the new horizontal braces across the existing
framing members a minimum of three framing spaces from the gable end wall,
the horizontal braces may be shortened provided that all of the following
conditions are met. |
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a.
The
horizontal brace shall be installed across a minimum of two framing spaces
and fastened to each existing framing member with three 3-inch long fasteners
(#8 wood screws or 10d nails). b.
The
minimum size of the anchor block shall be equivalent to the existing framing
members. The anchor block shall be
fastened to the side of the horizontal brace in the second framing space from
the gable end wall as shown in Figure A104.2.11. Six 3-inch long fasteners (#8 wood screws
or 10d nails) shall be used to fasten the anchor block to the side of the
horizontal brace. c.
The
anchor block shall extend beyond the surface of the horizontal brace that is
in contact with the existing framing members a minimum of one-half the depth
of the existing framing member. The
anchor block shall be installed tightly between the existing framing members
such that the gap at either end shall not exceed 1/8
inch. |
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Ray Burroughs Table A104.2, columns 3, 4, 5 and 6 reference several figures that I cannot find? |
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A104.3 Retrofit Studs. The
retrofit studs shall consist of the minimum size members for the height
ranges of the existing vertical gable end wall studs indicated in Table
A104.2. Retrofit studs shall be
installed adjacent to the existing or added (Section A104.2) vertical gable
end wall studs and extend from the top of the lower horizontal brace to the
bottom of the upper horizontal brace.
A maximum gap of 1/8-inch shall be permitted between the retrofit stud
and the bottom horizontal brace. A maximum
gap of 1/2-inch shall be permitted between the top edge of the retrofit stud
closest to the upper horizontal brace and the horizontal brace surface. Exception: Where
obstructions, other permanently attached obstacles or conditions exist that
will not permit the installation of a new retrofit stud adjacent to an
existing gable end wall stud, refer to Section A104.5 for permitted
modification of these prescriptive retrofit methods. |
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A104.3.1 Retrofit Stud Fastening.
Each retrofit stud shall be fastened to the top and bottom horizontal
brace members with a minimum of a 20 gauge, 11/4 inch
wide flat metal strap with pre-punched fastener holes. The flat metal straps shall be the minimum
length as indicated in Table A104.2.
Each top and bottom strap shall extend sufficient distance onto the
vertical face of the retrofit stud and be fastened with the number of 1-1/4
inch long fasteners (#8 wood screws or 8d nails) indicated in Table
A104.2. Each strap shall be fastened
to the top and bottom horizontal brace members with the minimum number of
1-1/4 inch long fasteners (#8 wood screws or 8d nails) as indicated in Table
A104.2. The retrofit stud members
shall also be fastened to the side of the existing vertical gable end wall
studs with 3-inch long fasteners (#8 wood screws or 10d nails) spaced at
6-inches on center as shown in Figure A104.2.1. A104.3.2 Retrofit Stud Splices.
Retrofit studs greater than 8-feet in height may be field spliced as
shown in Figure A104.3. |
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A104.4 Compression Blocks. Compression
blocks shall have minimum lengths as indicated in Table A104.2. Compression blocks shall be installed on
the horizontal braces directly against either the existing vertical gable end
wall stud or the retrofit stud. For
clarity, Figures A104.2.2 through A104.2.5 (trusses) and Figures A104.2.7
through A104.2.10 (rafters) show the installation of the compression block
against the existing vertical gable end wall stud with the strap from the
retrofit stud running beside the compression block. When the compression block is installed
against the retrofit stud, the block shall be allowed to be placed on top of
the strap. A maximum gap between the
compression block and the existing vertical gable end wall stud member or
retrofit stud of 1/8 inch shall be permitted. Compression blocks shall be fastened to the
horizontal braces with the minimum number of 3-inch long fasteners (#8 wood
screws or 10d nails). End and edge distances for fastener installation shall
be as listed in Section A103.7 and shown in Figures A104.2.2 through A104.2.5
(trusses) and Figures A104.2.7 through A104.2.10 (rafters). |
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A104.5
Obstructions – Permissible modifications to prescriptive gable end retrofits. Where obstructions, other permanently attached obstacles or conditions exist in attics that preclude the
installation of a retrofit stud or horizontal braces in accordance with
Sections A104.2 or A104.3, the gable end retrofit shall be deemed to meet the
requirements of this section if the requirements of Section A104.5.1 are met. Obstructions to the installation of
retrofit studs or horizontal braces include gable end vents, attic accesses,
recessed lights, skylight shafts, chimneys, air conditioning ducts, or
equipment. Where the installation of a
horizontal brace for the top of a center stud is obstructed by truss plates
near the roof peak, methods prescribed in A104.5.1 are permitted to be used,
or retrofit ridge ties as prescribed in Section A104.5.2 are permitted to be
used to support the horizontal brace. |
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A104.5.1 Remedial
measures where obstacles prevent installation of retrofit studs or horizontal
braces. If a retrofit stud or horizontal
brace cannot be installed because of an obstruction, the entire assembly can
be omitted from that location provided all of the following conditions are
met. 1.
No more than two assemblies of retrofit studs and
horizontal braces are omitted on a single gable end. 2.
There shall be at least two retrofit studs and
horizontal brace assemblies on either side of the locations where the retrofit
studs and horizontal bracing members are omitted (no two ladder braces
bearing on a single retrofit stud). 3.
The retrofit studs on each side of the omitted
retrofit stud are increased to the next indicated member size in Table A104.2
and fastened as indicated in Section A104.3.1. |
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4.
The horizontal bracing members on each side of the
omitted brace shall be sized in accordance with Table A104.2 for the required
retrofit studs at these locations. 5.
The horizontal bracing members on each side of the
omitted brace shall extend a minimum of three framing spaces from the gable
end wall unless anchor blocks are installed in accordance with Exception 2 of
Section A104.2. 6.
Ladder bracing is provided across the location of
the omitted retrofit studs as indicated in Figures A104.5.1.1 (trusses) and
A104.5.1.2 (rafters). 7.
Ladder bracing shall consist of a minimum 2x4
members oriented horizontally and spaced at 12-inches on center
vertically. Ladder bracing shall be
attached to each adjacent retrofit stud with a metal framing angle with a
minimum lateral capacity of 175 lbs.
Ladder bracing shall be attached to the existing stud at the location
of the omitted retrofit stud with a metal hurricane tie with a minimum
capacity of 175 lbs. 8.
Where ladder bracing spans across a gable end
vent, no attachment to the gable end vent framing shall be required. 9.
Notching of the ladder bracing shall not be
permitted. |
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A104.5.2
Retrofit ridge ties. When
obstructions along the ridge of the roof obstruct the installation of a
horizontal brace for one or more studs near the middle of the gable wall,
retrofit ridge ties may be used to provide support for the required
horizontal brace. Retrofit ridge tie members shall be
installed a maximum of 12 inches below the existing ridge line. The retrofit ridge tie members shall be
installed across a minimum of three bays to permit fastening of the
horizontal brace. A minimum of a 2x4
member shall be used for each ridge tie and fastening shall consist of two
3-inch long wood screws, four 3-inch long 10d nails or two 3-1/2 inch long
16d nails driven through and clinched at each top chord or web member
intersected by the ridge tie as illustrated in Figure A104.5.2. |
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Figure
A 104.5.2 |
Ray Burroughs Figure A104.5.2, references section 1504.5.2 and table 1504.2. I cannot find these referenced section or table? |
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A104.5.3
Notching of retrofit studs. Retrofit studs may be notched in one
location along the height of the stud member provided that all of the
following conditions are met. 1.
The
retrofit stud to be notched shall be sized such that the remaining depth of
the member at the location of the notch (including cut lines) shall not be
less than that required by Table A104.2. 2.
3.
The
notched retrofit stud shall not be spliced within 12 inches of the location
of the notch. The splicing member
shall not be notched and shall be installed as indicated in Figure A104.3. 4.
The
length of the flat metal straps indicated in Table A104.2 shall be increased
by the increased depth of the notched retrofit stud member to be installed. 5.
The
height of the notch shall not exceed 12 inches vertically as measured at the
depth of the notch. 6.
The
notched retrofit stud member shall be fastened to the side of the existing gable
end wall studs in accordance with Section A104.3.1. Two additional 3-inch fasteners (#8 wood
screws or 10d nails) shall be installed on each side of the notch in addition
to those required by Section A104.3.1. |
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A104.6
Connection of gable end wall to wall below. The bottom
chords or bottom members of wood framed gable end walls shall be attached to
the wall below using one of the methods prescribed in Sections A104.6.1 or
A104.6.2. The particular method chosen
shall correspond to the framing system and type of wall construction
encountered. Due to access
considerations, this retrofit needs to be carried out before any of the other
gable end retrofit activities referenced in Sections A104.2, A104.3, A104.4
or A104.5. |
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A104.6.1 Truss
gable end wall. The
bottom chords of the gable end wall shall be attached to the wall below using
right angle gusset brackets consisting of 14 gage or thicker material with a
minimum load capacity of 350 lbs perpendicular to the plane of either face of
the connector. The right angle gusset
brackets shall be installed throughout the portion of the gable end where the
gable end wall height is greater than 3 feet at the spacing specified in
Table A104.6. A minimum of two of the
fasteners specified by the manufacturer shall engage the body of the bottom
chord. Connection to the wall below
shall be by one of the methods listed below: |
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1.
For a wood frame wall below, the two fasteners
into the top of the wall below that are closest to the face of the gable end
bottom chord shall be 4-1/2 inches long and of the same diameter and style
specified by the bracket manufacturer.
Other fasteners shall be consistent with the bracket manufacturer’s
specifications for size, style and length. 2.
For a concrete or masonry wall below without a
sill plate, the fasteners into the wall shall be consistent with the bracket
manufacturer’s specifications for fasteners installed in concrete or masonry. 3.
For a concrete or masonry wall below with a 2x
sill plate, the fasteners into the wall below shall be of the diameter and
style specified by the bracket manufacturer for concrete or masonry
connections; but, long enough to pass through the wood sill plate and provide
the required embedment into the concrete or masonry below. Alternatively, the bracket can be anchored
to the sill plate using fasteners consistent with the bracket manufacturer’s
specifications for wood connections provided, the sill plate is anchored to
the wall on each side of the bracket by a 1/4-inch diameter masonry screw
with a 2-1/2 inch embedment into the concrete or masonry wall. ¼-inch washers shall be placed under the
heads of the masonry screws. |
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A104.6.2
Conventionally framed gable end wall. Each stud in a
conventionally framed gable end wall, throughout the length of the gable end
wall where the wall height is greater than 3-feet, shall be attached to the
bottom or sill plate using a stud to plate connector. The bottom or sill plate shall then be
connected to the wall below using one of the methods listed below: 1.
For
a wood frame wall below, the sill or bottom plate shall be connected to the
top plates below using ¼-inch diameter screws 4-1/2 inches long. The fasteners shall be installed at the
spacing indicated in Table A104.6. 2.
For
a concrete or masonry wall below, the sill or bottom plate shall be connected
to the concrete or masonry wall below using ¼-inch diameter concrete or
masonry screws of sufficient length to provide a 2-1/2 inch embedment into
the top of the concrete or masonry wall.
The fasteners shall be installed at the spacing indicated in Table
A104.6. |
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