Texas Department of Insurance - GHBA · 2020. 8. 17. · 35 1.05 1.45 1.70 40 1.09 1.49 1.74 45...

Texas Department of InsuranceAdopted 2018 I-Codes

Adopted Codes

2018

International Residential Code

International Building Code

Without Texas Revisions

2018 International Residential Code

Figure R301.2(4)A Ultimate Design Wind Speeds

2018 International Residential Code – Figure R301.2(5)A


Wind Zones

• Inland II

• Inland I

• Seaward

Will not be used to determine Wind Speeds

Wind speeds will be determined by the maps in the I-Codes



R301.2.1 Wind design criteria

Cladding and components require “design load performance”

Items such as:

Wall coverings

Curtain walls

Roof coverings

Exterior windows

Skylights

Garage doors

Exterior doors

Visit: https://tdi.texas.wind/prod/index.html

https://tdi.texas.wind/prod/index.html


R301.2.1.1 Wind limitations and wind design required

in accordance with Figure R301.2(5)B

• AWC Wood Frame Construction Manual (WFCM)

• ICC Standard for Residential Construction in High-Wind

Regions (ICC 600)

• ASCE 7 Minimum Design Loads for Buildings and Other

Structures

• AISI Standard for Cold-Formed Steel Framing (AISI S230)

• International Building Code

The design of building for wind loads shall be in accordance with one or more of

the following:


Figure R301.2(4)B Wind Design is Required

2018 International Residential Code – Figure R301.2(5)B

2018 International Residential Code – Design Pressure Factors

Wind Speeds


2018 International Building Code

Table 1604.5 – Risk Category of Building and other Structures

Risk Category Nature of Occupancy

I Low hazard to human life in the event of failure

II Other structures not listed in Risk Categories I, III, or IV

III Substantial hazard to human life in the event of failure

IV Essential facilities

2018 International Residental Code

R301.2.1 – Wind Design Criteria

Where not otherwise specified, the wind loads listed in Table

R301.2(2) adjusted for height and exposure using Table

R301.2(3) shall be used to determine design load performance


Mean Roof Height and Building Exposure Adjustment Coefficients

Mean Roof

Height

Building Exposure

B C D

15 0.82 1.21 1.47

20 0.89 1.29 1.55

30 1.00 1.40 1.66

35 1.05 1.45 1.70

40 1.09 1.49 1.74

45 1.12 1.53 1.78

50 1.16 1.56 1.81

55 1.19 1.59 1.84

60 1.22 1.62 1.87


R301.2.1.4 Exposure B Category

“Urban and suburban areas,

wooded areas or other terrain with

numerous closely spaced

obstructions having the size of

single-family dwellings or larger.

Exposure B shall be assumed

unless the site meets the definition

of another type exposure.”


R301.2.1.4 Exposure C Category

“Open terrain with scattered obstructions, including surface undulations or other

irregularities, having heights generally less than 30 feet (9144 mm) extending more

than 1,500 feet (457 m) from the

building site in any quadrant. This

exposure shall apply to any building

located within Exposure B type terrain

where the building is directly adjacent

to open areas of Exposure C type terrain

in any quadrant for a distance of more

than 600 feet (183 m). This category

includes flat, open country and

grasslands.”


R301.2.1.4 Exposure D Category

“Flat, unobstructed areas exposed to wind

flowing over open water, smooth mud flats,

salt flats and unbroken ice for a distance of

not less than 5,000 feet (1524 m) This

exposure shall apply only to those buildings

and other structures exposed to the wind

coming from over the unobstructed area.

Exposure D extends downwind from the edge

of the unobstructed area a distance of 600

feet (183 m) or 20 times the height of the

building or structure, whichever is greater.”

2018 International Residential Code – Product Evaluations

TDI does not approve or endorse the use of any product manufacturer or building product

To search for tested products, visit:


The Department recognizes other recognized entities, such as:

International Code Council (ICC)

Miami-Dade County

Factory Mutual


2018 International Residential Code – Windows & Doors

R609.2 Performance

Exterior windows and doors

• Must be designed to resist wind loads adjusted for height and

exposure; or

• By ASCE 7 using allowable stress design load combinations of

ASCE 7


R609.2 Performance

• Exterior windows and doors tested per AAMA/WDMA/CSA

101/I.S.2/A440 – 17, or AMD 100

1. Required Design Pressures determined from ASCE 7

using the ultimate strength design may be multiplied by

0.6


R609.3 Testing and labeling

Exterior windows and sliding glass doors

1. AAMA/WDMA/CSA 101/I.S.2/A440 – 17

Exterior side-hinged doors

1. AAMA/WDMA/CSA 101/I.S.2/A440 – 17, or

AMD 100

Design Pressures using ASCE 7-16

Design Wind Pressure Requirements for Windows,

Exterior Doors and Impact Protective Systems (Shutters)

120 mph 130 mph 140 mph 150 mph 160 mph 170 mph

+14.8 / -19.4 +17.4 / -22.8 +20.2 / -26.4 +23.2 / -30.3 +26.6 / -34.5 +29.8 / -38.9

Based on MRH of 30 Feet and Exposure B conditions

Corner Zones

2018 International Residential Code – Protection of Openings

R301.2.1.2 Protection of Openings

Exterior glazing in buildings located in windborne debris

regions shall be protected from windborne debris. Glazed

opening protection for windborne debris shall meet the

requirements of the Large Missile Test of ASTM E1996 and

ASTM E1886 as modified in Section 301.2.1.2.1

Garage door glazed opening protection for windborne debris

shall meet the requirements of an approved impact-resisting

standard or ANSI/DASMA 115


R301.2.1.2 Protection of Openings

Permits glazed openings in hurricane-prone regions to be

protected with 7/16” Wood Structural Panels

• Required in areas where the ultimate design wind

speed, Vult, is 140mph or greater

• Requires corrosion-resistant fasteners

• Fasteners are required to be permanently attached

to building


Permits glazed openings to be protected with 7/16” Wood Structural Panels

Fastener Type Fastener Spacing (inches)

Panel

span < 4

feet

4 feet <

panel span

< 6 feet

6 feet <

panel span

< 8 feet

No. 8 wood screw based

anchor with 2-inch

embedment length

16 10 8

No. 10 wood screw based

anchor with 2-inch

embedment length

16 12 9

¼-Inch lag based anchor

with 2-inch embedment

length

16 16 16

Table R301.2.1.2 Protection of Openings

2018 International Residential Code – Roof Coverings

Table R905.1.1(1) Underlayment Types

Roof Covering SectionMaximum Ultimate Design

Wind Speed, Vult < 140mph

Maximum Ultimate Design

Wind Speed, Vult > 140mph

Asphalt Shingles R905.2ASTM D 226 Type I

ASTM D 4869 Type I, II, III, or IV

ASTM D 6757

ASTM D 226 Type II

ASTM D 4869 Type IV

ASTM D 6757

Clay and concrete tile R905.3ASTM D 226 Type II

ASTM D 2626 Type I

ASTM D 6380 Class M mineral surfaced roll roofing

ASTM D 226 Type II

ASTM D 2626 Type I

ASTM D 6380 Class M mineral surfaced roll roofing

Metal roof shingles R905.4ASTM D 226 Type I or II


ASTM D 226 Type II

ASTM D 4869 Type IV

Mineral-surfaced roll roofing R905.5ASTM D 226 Type I or II


ASTM D 226 Type II

ASTM D 4869 Type IV

Slate and slate-type shingles R905.6ASTM D 226 Type I or II


ASTM D 226 Type II

ASTM D 4869 Type IV

Wood shingles R905.7ASTM D 226 Type I or II


ASTM D 226 Type II

ASTM D 4869 Type IV

Wood shakes R905.8ASTM D 226 Type I or II


ASTM D 226 Type II

ASTM D 4869 Type IV

Metal panels R905.10 Manufacturer’s instructionsASTM D 226 Type II

ASTM D 4869 Type IV


Table R905.1.1(1) Underlayment Types

Underlayment is required to bear a

label indicating compliance

to the Standard designation

(ASTM D#) and the Type

Classification

ASTM D226, Type II

ASTM D4869, Type III or IV

ASTM D6757

ASTM D1970Synthetic Underlayments are

not specifically addressed in the 2018 IRC

Hold unto the underlayment wrappers for the inspector


Table R905.1.1(2) Underlayment Application

Roof Covering (Type) Maximum Ultimate Design

Wind Speed, Vult 140 mph

Asphalt Shingles 2:12 to 4:12 – “Underlayment shall be two layers

applied in the following manner: apply a 19-inch strip of

underlayment felt parallel to and starting at eaves.

Starting at the eave, apply 36-inchwide sheets of

underlayment, overlapping successive sheets 19 inches.”

Same as Maximum Ultimate Design Wind

Speed, Vult


Table R905.1.1(3) Underlayment Application

Roof Covering (Type) Maximum Ultimate Design

Wind Speed, Vult 140 mph

Asphalt Shingles Fasten sufficiently to hold in place Attach “with corrosion-resistant fasteners in a grid pattern of

12 inches between laps with a 6-inch spacing at side laps”

Attach with “metal or plastic cap nails or cap staples with a

nominal cap diameter of not less than 1 inch. Metal caps shall

have a thickness of not less than 32-gage sheet metal. Power-

driven metal caps shall have a minimum thickness of 0.010

inch. Minimum thickness of the outside edge of plastic caps

shall be 0.035 inch. The cap nail shall be not less than 0.083

inch for ring shank cap nails and 0.091 inch for smooth shank

cap nails. Cap nail shank and cap staple legs shall have a

length to penetrate the roof sheathing or not less than ¾ inch

into the roof sheathing.”

Please check Table R905.1.1(2) for underlayment

applications for additional roof covering types


Table R905.2.4.1 Classification of Asphalt Roof Shingles

Maximum Ultimate

Design

Wind Speed, Vult From

Figure R301.2(4)A (mph)

Maximum Ultimate

Design

Wind Speed, Vasd From

Table R301.2.1.3 (mph)

ASTM D 7158

Shingle Classification

ASTM D 3161

Shingle Classification

110 – 129 85 – 100 G or H A, D, or F

142 – 155 110 – 120 G or H F

168 – 194 130 – 150 H F

Hold unto the shingle

wrappers for the inspector


Table R905.2.5 Fasteners for Asphalt Roof Shingles

• Galvanized steel

• Stainless steel

• Aluminum

• Copper

Fasteners must be:

• 12-Gage shank

• 3/8-Inch diameter head

• 3/4” Decking penetration

• Complying with ASTM

F1667

Fasteners must be a minimum of:


Table R905.2.6 Attachment of Asphalt Roof Shingles

• Shingles shall have the minimum number of fasteners required by

manufacturer’s approved installation instructions

• Shingles shall not have less than four fasteners per strip shingle or

two fasteners per individual shingle

• Shingles on slopes greater than

21:12 shall be installed in

accordance with the manufacturer’s

approved installation instructions


R905.2.8.2 Valleys

Valley linings:

1. Open valleys (Metal)

• Refer to Table R905.2.8.2

2. Open valleys

• Two-Ply mineral surface roll-roofing complying with ASTM D3909

or ASTM D6380, Class M

3. Closed valleys

• One-ply mineral surface roll-roofing complying with ASTM D6380

or other valley linings described in bullet 1 and 2

• Self-adhered polymer-mod. bit. complying with ASTM D1970


Table R905.2.8.2 Valley Lining Material

MaterialMinimum Thickness

(inches)Gage

Weight

(pounds)

Cold-rolled copper 0.0216 nominal –ASTM B370

16 ounces per square foot

Lead-coated copper 0.0216 nominal –ASTM B101


High-yield copper 0.0162 nominal –ASTM B370


Lead-coated high-yield copper 0.0162 nominal –ASTM B101


Aluminum 0.024 – –

Stainless steel – 28 –

Galvanized steel 0.0179 26 (zinc coated G90) –

Zinc alloy 0.027 – –

Lead – – 2 ½

Painted terne – – 20


R905.2.8.3 Sidewall flashing

• Required to be continuous or step flashing

• Must be a minimum of 4 inches high and 4 inches wide

• The vertical leg of continuous flashing is required to be

installed under siding

• For masonry veneer, flashing is required as per R703.8.2.2

• For exterior plaster or adhered masonry veneer, flashing is

required as per R703.6.3


R905.2.8.5 Drip edge

• Must be provided at the eaves and rake edges

• Must lap adjacent pieces at least 2 inches

• Must extend at least ¼ inches below roof sheathing and at least

2 inches onto roof sheathing

• Must be fastened a maximum of 12 inches on center

• Must be applied under the underlayment at the eaves and over

the underlayment on the rake edges

Design Pressures using ASCE 7-16

Design Wind Pressure Requirements for

Mechanically Attached Roof Covering Materials

Roof Slope 120 mph 130 mph 140 mph 150 mph 160 mph 170 mph

>0 ͦ to 7 ͦ +10.0 / -44.5 +10.0 / -52.3 +10.0 / -60.6 +10.0 / -69.5 +11.2 / -79.14 +12.7 / -89.3

>7 ͦ to 20 ͦ +10.0 / -49.8 +11.0 / -58.4 +12.8 / -67.7 +14.7 / -77.8 +14.7 / -88.5 +18.9 / -99.9

>20 ͦ to 27 ͦ +10.0 / -45.5 +11.0 / -53.4 +12.8 / -61.9 +14.7 / -71.1 +16.7 / -80.9 +18.9 / -91.3

>27 ͦ to 45 ͦ +14.2 / -35.9 +16.7 / -42.2 +19.4 / -49.0 +22.2 / -56.2 +25.3 / -63.9 +28.6 / -72.2

Based on MRH of 30 Feet and Exposure B conditions

Perimeter Zones


R908.3 Roof replacement

• Roof replacement shall include the removal of existing

layers of roof coverings down to the roof deck (no felt,

shingles, insulation or built-up roof)

• One existing layer of ice barrier, adhered to the deck,

may be left in place with an additional layer of ice

barrier installed

Let us know if we can help you!

For more information or for answers to general questions:

Contact TDI Engineering at

(800)248-6032, Option 5

Texas Department of Insurance - GHBA · 2020. 8. 17. · 35 1.05 1.45 1.70 40 1.09 1.49 1.74 45...

Documents

Transcript of Texas Department of Insurance - GHBA · 2020. 8. 17. · 35 1.05 1.45 1.70 40 1.09 1.49 1.74 45...