SECTION 5.4007. Applicable Building Code Standards in Designated Catastrophe Areas for Structures Constructed, Repaired or to Which Additions Are Made Prior to September 1, 1998

(a) Areas Seaward of the Intracoastal Canal.

(1) Applicability. This code contains requirements for the construction of buildings to minimize damage to such buildings by severe windstorms which occur along the Gulf Coast. Where specific requirements for particular devices or methods of construction are specified, alternate methods or practices which are considered equal may be used. Such consideration is to based on sound engineering practice and experience. The degree of protection against damage from windstorm provided by these requirements cannot be assured for tornadoes, but such compliance should be helpful to some degree in reducing tornado damage. The requirements herein are applicable only to properties located seaward of the Intracoastal Canal on the Texas coastline (or seaward of the boundary authorized to be established by the Commissioner by the Insurance Code, Article 21.49, as amended). The requirements herein shall apply, on or after October 10, 1988, to May 31, 1998, to new construction of, and additions or repairs to, structures located seaward of the Intracoastal Canal in areas previously exempt from the requirements of this subsection. The property previously exempt was that property protected by a sea wall constructed by the Corps of Engineers.

(2) Building code standards.

(A) Wind pressure.

(i) When considered. All buildings and structures shall be designed to resist a horizontal wind pressure on all surfaces exposed to the wind, allowing for wind in any direction, in accordance with the following table. No allowance shall be made for the shielding effect of other buildings or structures. The height is to be measured above the average level of the ground adjacent to the building or structure.

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(ii) Exterior walls. Exterior walls shall be designed to withstand the pressures specified in clause (i) of this subparagraph, acting either inward or outward.

(iii) Roofs.

(I) The roofs of buildings and structures shall be designed and constructed to withstand pressures, acting outward normal to the roof surface, equal to 1 1/4 times the pressures specified in clause (i) of this subparagraph. The height is to be taken as the vertical distance from the average elevation of the ground adjoining the building to the average elevation of the roof.

(II) Roofs or sections of roofs with slopes greater than 30 degrees shall be designed and constructed to withstand pressures, acting inward normal to the surface, equal to those specified in clause (i) of this subparagraph and applied to the windward slope only.

(III) Overhanging eaves and cornices shall be designed and constructed to withstand outward pressures equal to twice those specified in clause (i) of this subparagraph.

(iv) Chimneys, tanks and towers. Chimneys, tanks, solid towers, and similar structures shall be designed and constructed to withstand the pressures specified in clause (i) of this subparagraph multiplied by the following factors:

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(v) Other structures. The design wind pressures for structures not covered in this paragraph shall be in accordance with generally accepted engineering practice and shall be subject to the approval of the building official.

(vi) Stability. The overturning moment due to wind pressure shall not exceed 50% of the moment of stability due to the dead load only, unless the building or structure is securely anchored to the foundation to resist this force.

(vii) Roofing materials. Roofing materials must pass the U.L. Standard 997 or a comparable test certified by the Commissioner and be installed as required by the Department, to promote wind resistance of the materials.

(B) Anchorage.

(i) Heavy timber construction (as defined in the Texas Commercial Property Rating Manual in effect prior to September 1, 1994). Every roof girder and every roof beam shall be anchored to an exterior or interior wall or to a properly designed interior column. Wall beams and plates shall be anchored to the wall with approved type anchors not more than four feet apart. Roof planking where supported by a wall shall be anchored to such wall at intervals not exceeding four feet. Roof trusses shall be securely anchored to masonry walls at point of bearing. Monitor and saw tooth construction shall be anchored to the main roof construction. Anchors shall consist of steel or iron bolts or straps of sufficient strength and ample anchorage to resist vertical uplift of the roof as required in subparagraph (A)(iii) of this paragraph.

(ii) Ordinary construction (masonry).

(I) All trimmers and at least one beam or joist in every four feet resting on masonry walls shall be secured to such walls by approved metal anchors attached at or near the bottom in a manner to be self-releasing. Each end of a trimmer, beam, or joist that is supported by a girder shall be secured or tied in an approved manner to such girder or to a trimmer, beam, or joist correspondingly supported from the opposite side of such girder. Anchors and ties shall be so arranged as to form continuous ties between opposite masonry walls.

(II) Where floor or roof joists or beams run parallel to masonry walls, such walls shall be secured to four or more joists of the floor or roof construction by approved metal anchors at maximum intervals of eight feet for dwellings, and six feet in other buildings.

(III) Wall plates and roof construction shall be anchored to the walls at least every six feet, except that wall plates and roof construction shall be anchored at intervals of four feet to hollow concrete masonry walls which do not have cast-in-place reinforced concrete tie beams.

(IV) Wooden girders shall be anchored to the walls and fastened to each other with suitable steel straps placed near the bottom of the girder.

(V) At least every third rafter shall be anchored to the ceiling joists or partitions directly beneath by not less than the equivalent of one-by-six-inch boards securely nailed. Such braces shall be attached to the rafters at their midpoints or at the third points if two are used per rafter. In peaked roofs opposite rafters shall be laterally braced to each other at the ridge in a manner satisfactory to the building official.

(VI) Roof trusses shall be securely anchored to masonry walls at points of bearing.

(VII) Anchors shall consist of steel or iron bolts or straps of sufficient strength and ample anchorage to resist vertical uplift of the roof as required in subparagraph (A)(iii) of this paragraph.

(iii) Wood frame construction.

(I) Sills shall be anchored to the foundation walls to develop a strength equivalent to 1/2-inch bolts with proper washers embedded six inches in concrete foundation walls and spaced six feet apart.

(II) Rafters shall be anchored to the wall plate by approved metal anchors attached to at least every other rafter or shall be otherwise anchored in an approved manner.

(III) In all buildings 20 feet or more in width where joists run at right angles to the rafters, the rafters shall be tied to the ceiling joists with wood or metal ties nailed to the foot of alternate rafters and extending across four joists well nailed to each joist.

(IV) Girders resting on masonry foundation walls or piers shall be anchored thereto with not less than 1/2-inch bolts embedded at least six inches in masonry.

(V) Wooden columns and posts shall be securely anchored to their foundations and to the members which they support.

(VI) At least every third rafter shall be anchored to the ceiling joists or partitions directly beneath by not less than the equivalent of one-by-six-inch board securely nailed. Such braces shall be attached to the rafters at their midpoints or at the third points if two are used per rafter.

(VII) Each rafter shall be laterally braced to the opposite rafter at a point underneath the ridge, in order to form a brace known as the "A" type of "collar beam," except that roof construction of the "exposed cathedral type" or "exposed shed type" may have such bracing omitted when the rafters are securely anchored and braced in an approved manner. Roof framing and trussing of all other types of roof construction shall be anchored by an approved method.

(C) Roof covering installation.

(i) General requirements for all roof coverings. Roof coverings shall be securely attached to the roof in accordance with the manufacturer's installation instructions and specifications and with the methods approved by the building official. Nails, clips, and similar attaching devices shall be galvanized or otherwise suitably corrosion resistant.

(ii) Prepared shingle roof coverings.

(I) Wood roof decks to which prepared shingles are applied shall be solidly sheathed. Sheathing shall be well seasoned and dry. Sheathing boards shall be at least one inch nominal dimension boards not over six inches wide. Plywood sheathing shall be at least 5/8 of an inch thick.

(II) Attic spaces shall be vented with vent openings so placed as to circulate air in all parts of the attic.

(III) Nails shall be of sufficient length to extend through the roof deck (sheathing).

(IV) Thick-butt asphalt shingles shall be nailed in the thick portion of the shingle.

(V) All butts or tabs of asphalt shingles shall be securely spotted or tabbed with a plastic, fibrous, asphalt cement or anchored by clips or locks, and all edges at eaves and gable shall be set in such cement three inches back from the edge.

(VI) Metal drip edges shall be nailed to the roof deck with nails not less than ten inches on centers.

(iii) Built-up roof coverings.

(I) For built-up roof coverings cant strips shall be provided at the angle of roof and vertical surfaces.

(II) Built-up roof coverings shall be carried at least six inches above the cant strip to a reglet in the parapet and covered with metal flashing caulked into the reglet. Reglet may be omitted at parapet walls provided two layers of felt or the equivalent are carried across the top of the parapet under coping and down the parapet to the lower edge of the cant strip. The said layers are to run vertically, properly lapped and cemented to the parapet.

(III) All resinous places in the wood roof deck shall be covered with sheathing paper or unsaturated felt.

(IV) The first layer or anchor sheet shall be not less than 30-pound felt nailed six inches on center along with a two-inch lap and nailed 12 inches on center both ways in the area between laps with tin caps and one-inch nails; or shall be not less than two layers of 15-pound felt lapped 18 inches and nailed through both sheets on six-inch centers along the lap and on 12-inch centers in the area between laps with tin caps and one-inch nails; or where the underside of the roof sheathing is to be exposed and its appearance considered, the first layer shall be not less than a 30-pound felt or two layers of 15-pound felt nailed six inches on centers along the rafters with tin caps and 1-1/4 inch nails, and nailed 12 inches on centers both ways, between rafters, with tin caps and 3/4 inch nails.

(V) Each additional sheet above the anchor sheet shall be thoroughly mopped between layers with a bituminous compound so that no layers touch an unmopped layer. Bituminous compound for mopping plys together shall be air refined asphalt or coal tar pitch but shall not be any type of emulsion, cold or cut back liquid cement, oil, or grease.

(VI) Gravel stop and drip strips, and eave and gable drips shall be not less than Number 26 gauge galvanized metal, 16 ounce copper or 0.024 inch aluminum, with not less than three-inch flange on roof and nailed with not less than 3/4 inch nails spaced not more than six inches apart.

(iv) Roll roofing.

(I) Roll roofing shall be applied only over a smooth surface. Roll roofing shall not be applied over shingle roofs.

(II) Roll roofing applied in a shingle layer shall be spot mopped and applied by concealed nail method with a minimum three inch head lap and a minimum six inch end lap properly cemented. Nail spacing shall be not less than four inches on centers.

(III) Nails that secure roll roofing to the roof deck shall be driven at least 3/4 of an inch from the edge of the sheet.

(v) Tile roofing.

(I) Tile roofing shall be laid over not less than one layer of 30-pound asphalt felt securely fastened by nailing with tin caps.

(II) All tile shall be thoroughly watered with a hose before application.

(III) Every tile shall be laid full length in portland cement mortar and in addition the first three horizontal courses shall be nailed. Under certain conditions additional nailing may be required to prevent the tile from slipping. Mortar shall be not less than one part cement and three parts sand and not more than 25% lime by volume.

(IV) All nails for flashing and tiles shall be copper.

(vi) Corrugated metal roofing, protected metal roofing, corrugated and flat sheet asbestos cement roofing.

(I) When roofings of the previously mentioned types are applied to wood roof decks, they shall be secured with drive screws of sufficient length to extend through the roof deck. When applied directly to purlins and other roof members they shall be secured with bolted strap fasteners. Properly designed clip fasteners that are approved may be used in accordance with the conditions of such approval. Drive screws at least four inches in length may be used to secure these roofings directly to wood purlins.

(II) Aluminum roofing when fastened to steel roof structures shall be insulated against electrogalvanic action.

(vii) Insulated steel deck roofing. Insulated steel deck shall be secured by spot welding of clips or spot welding the sheets to the steel purlins, or by equivalent means.

(D) Construction walls. During erection masonry walls shall not be built higher than ten times their thickness unless adequately braced or until provision is made for the prompt installation of permanent bracing at the floor or roof level immediately above the story under construction.

(b) Areas Inland of the Intracoastal Canal. To be eligible for catastrophe insurance, properties located inland of the Intracoastal Canal on the Texas coastline (or inland of the boundary authorized to be established by the Commissioner by the Insurance Code, Article 21.49 as amended) shall be subject to the building specifications and standards in the Standard Building Code, as amended May 8, 1973, and the Windstorm Resistant Construction Guide. The Department adopts by reference the Windstorm Resistant Construction Guide, and any applicable amendments adopted by reference to be effective April 1, 2001, which has been developed by the Department to interpret and simplify the specifications and standards in the Standard Building Code, as amended May 8, 1973.

(c) Limitations on applicability of building codes. Notwithstanding any other provisions in this plan of operation, the building code set forth in this section shall be applicable only in:

(1) the counties of Aransas, Brazoria, Calhoun, Cameron, Chambers, Galveston, Jefferson, Kenedy, Kleberg, Matagorda, Nueces, Refugio, San Patricio, and Willacy;

(2) the area located east of the boundary line of State Highway 146 and inside the city limits of the City of Seabrook (Harris County) and the area located east of the boundary line of State Highway 146 and inside the city limits of the City of La Porte (Harris County);

(3) the City of Morgan's Point (Harris County); and

(4) the area located east of the boundary line of State Highway 146 and inside the city limits of the City of Shoreacres (Harris County), and the area located east of the boundary line of State Highway 146 and inside the city limits of the City of Pasadena (Harris County).

(d) Insurable property for windstorm and hail insurance.

(1) For structures before January 1, 1988, in all designated catastrophe areas. A structure constructed, repaired, or to which additions were made before January 1, 1988, that is located in an area covered at the time by a building code recognized by the association shall be considered an insurable property for windstorm and hail insurance from the association without compliance with the inspection or approval requirements of Insurance Code, Article 21.49, §6A(a) or the plan of operation. A structure constructed, repaired, or to which additions were made before January 1, 1988, that is located in an area not covered by a building code recognized by the association shall be considered an insurable property for windstorm and hail insurance from the association without compliance with the inspection or approval requirements of Insurance Code, Article 21.49, §6A(a) or the plan of operation if that structure has been previously insured by a licensed insurance company authorized to do business in this state and the risk is in essentially the same condition as when previously insured, except for normal wear and tear, and without any structural change other than a change made according to code. Evidence of previous insurance includes a copy of a previous policy, copies of canceled checks or agent's records that show payments for previous policies, and a copy of the title to the structure or mortgage company records that show previous policies.

(2) For structures in designated catastrophe areas of Seabrook and La Porte from January 1, 1988, to March 1, 1996. A structure constructed, repaired, or to which additions were made on and after January 1, 1988, and before March 1, 1996, that is located in an area east of the boundary line of State Highway 146 and inside the city limits of the City of Seabrook (Harris County) or in an area east of the boundary line of State Highway 146 and inside the city limits of the City of La Porte (Harris County) shall be considered approved by the Commissioner of Insurance as being in compliance with the association's inland building code requirements contained in subsection (b) of this section and shall be considered an insurable property for windstorm and hail insurance from the association if the owner of the structure to be insured by the association presents to the association at the time of application for insurance the following statement signed by a city building official: "To the best belief and knowledge of the undersigned, the structure located at (street address) in (name of city), Texas, was constructed, repaired, or an addition was made on and after January 1, 1988, and before March 1, 1996, in accordance with the building specifications and standards which comply with the Standard Building Code (1973 Edition) or an equivalent recognized code; and the City of (name of city), Texas has inspected the structure and enforced compliance to said code."

(3) For structures in the designated catastrophe areas of Seabrook and La Porte on and after March 1, 1996, to May 31, 1998. A structure constructed, repaired, or to which additions were made on and after March 1, 1996, to May 31, 1998, that is located in an area east of the boundary line of State Highway 146 and inside the city limits of the City of Seabrook (Harris County) or in an area east of the boundary line of State Highway 146 and inside the city limits of the City of La Porte (Harris County) shall be considered an insurable property for windstorm and hail insurance from the association only if the structure is inspected or approved by the Commissioner of Insurance for compliance with building specifications in this plan of operation, including any specifications for roofing materials as provided in Article 21.49, §6A(a) of the Insurance Code.

(4) For structures in the City of Morgan's Point from January 1, 1988, to June 1, 1996. A structure constructed, repaired, or to which additions were made on and after January 1, 1988, and before June 1, 1996, that is located in the City of Morgan's Point (Harris County) shall be considered approved by the Commissioner of Insurance as being in compliance with the association's inland building code requirements contained in subsection (b) of this section and shall be considered an insurable property for windstorm and hail insurance from the association if the owner of the structure to be insured by the association presents to the association at the time of application for insurance the following statement signed by a city building official: "To the best belief and knowledge of the undersigned, the structure located at (street address) in Morgan's Point, Texas, was constructed, repaired, or an addition was made on and after January 1, 1988, and before June 1, 1996, in accordance with the building specifications and standards which comply with the Standard Building Code (1973 Edition) or an equivalent recognized code; and the City of Morgan's Point, Texas, has inspected the structure and enforced compliance to said code."

(5) For structures in the City of Morgan's Point on and after June 1, 1996, to May 31, 1998. A structure constructed, repaired, or to which additions were made on and after June 1, 1996, to May 31, 1998, that is located in the City of Morgan's Point (Harris County); shall be considered an insurable property for windstorm and hail insurance from the association only if the structure is inspected or approved by the Commissioner of Insurance for compliance with building specifications in this plan of operation, including any specifications for roofing materials as provided in Article 21.49, §6A(a) of the Insurance Code.

(6) For structures located in an area east of a boundary line of State Highway 146 and inside the city limits of the City of Shoreacres (Harris County), and in an area east of a boundary line of State Highway 146 and inside the city limits of the City of Pasadena (Harris County), from January 1, 1988, to March 1, 1997. A structure constructed, repaired, or to which additions were made on and after January 1, 1988, and before March 1, 1997, that is located in an area east of State Highway 146 and inside the city limits of the City of Shoreacres (Harris County), or in an area east of State Highway 146 and inside the city limits of the City of Pasadena (Harris County), shall be considered approved by the Commissioner of Insurance as being in compliance with the association's inland building code requirements contained in subsection (b) of this section, and shall be considered an insurable property for windstorm and hail insurance from the association, if the owner of the structure to be insured by the association presents to the association at the time of application for insurance the following statement signed by a city building official: "To the best belief and knowledge of the undersigned, the structure located at (street address) in the City of __________ (insert name of city), Texas, was constructed, repaired, or an addition was made on and after January 1, 1988, and before March 1, 1997, in accordance with the building specifications and standards which comply with the Standard Building Code (1973 Edition) or an equivalent recognized code; and the City of __________ (insert name of city), Texas, has inspected the structure and enforced compliance to said code."

(7) For structures in an area east of a boundary line of State Highway 146 and inside the city limits of the City of Shoreacres (Harris County) and in an area east of a boundary line of State Highway 146 and inside the city limits of the City of Pasadena (Harris County) on and after March 1, 1997, to May 31, 1998. A structure constructed, repaired, or to which additions were made on and after March 1, 1997, to May 31, 1998, that is located in an area east of a boundary line of State Highway 146 and inside the city limits of the City of Shoreacres (Harris County), or in an area east of a boundary line of State Highway 146 and inside the city limits of the City of Pasadena (Harris County), shall be considered an insurable property for windstorm and hail insurance from the association only if the structure is inspected or approved by the Commissioner of Insurance for compliance with building specifications in this plan of operation, including any specifications for roofing materials, as provided in Article 21.49, §6A(a) of the Insurance Code.

Source Note: The provisions of this §5.4007 adopted to be effective July 21, 1997, 22 TexReg 6624; amended to be effective September 1, 1998, 23 TexReg 7581; amended to be effective April 1, 2001, 26 TexReg 1151