4-60 Protect the structural steel during concreting and any other operations that are particularly
hazardous with respect to soiling the steel. Remove any foreign matter which gets on the steel as soon as possible by either solvent cleaning, hand tool cleaning, power tool cleaning, blast cleaning or a combination thereof, as necessary to restore the surfaces to the specified condition.
440-10 Measurement and Payment
Approx . ____ Lbs. Structural Steel will be measured and paid at the contract lump sum price. The approximate quantity shown in the contract pay item is an estimate based on the computed weight of the structural steel necessary to complete the work. No measurement for payment will be made for this pay item, and no adjustment in the contract lump sum price will be made for any variation from the approximate quantity shown except for revisions in the plans which affect the quantity of structural steel necessary to complete the work. When revisions in the plans have been made which affect the quantities of structural steel, adjustments in compensation will be made by supplemental agreement. When the contract includes the item of Paintin g of Structural Steel , all work of painting except for shop painting will be paid as provided in Article 442- 15 and payment for shop painting will be included in the contract lump sum price for Approx . ____ Lbs. Structural Steel . When the contract exclude s the item of Painting of Structural Steel, payment at the contract lump sum price for Approx . ____ Lbs. Structural Stee l will be full compensation for both shop and field painting. Elastomeric Bearings will be paid as provided in Article 430- 8. The price and payment will be full compensation for all items required to construct steel structures including , but not limited to , those items contained in Article 440 -1. Payment will be made under: Pay Item Pay Unit Approx . ____ Lbs. Structural Steel Lump Sum
442-1 Description
Paint steel structures and properly prepare metal surfaces; apply, protect and dry paint coatings; protect pedestrian, vehicular, water or other traffic upon or underneath the structure; protect all portions of the structure and adjacent work against disfigurement by splatters, splashes, overspray and smirches of paint or of paint materials; a pply paint in the shop and field; and furnish blast cleaning equipment, paint spraying equipment, brushes, rollers, paint cleaning abrasives, cleaning solvents, tools, tackle, scaffolding, labor and any other materials, hand or power tools, inspection equi pment and personal protective and safety equipment necessary for the entire work.
442-2 Materials
Refer to Division 10. Item Section Abrasive Materials for Blast Cleaning 1080 -12 Paint and Paint Materials 1080
442-3 Definitions
Define “corner” as the intersection of 2 surfaces that are not in the same plane. Define “inaccessible areas” as partially or completel y enclosed surfaces, the majority of which are not visible without the use of special devices such as mirrors. Define “sharp edge” as a corner on a steel section that ends in a point or edge and appears able to cut human flesh. Define “raised
4-61 weld” as fil let welds or groove welds that have not been ground flush. Define “stripe coat” as
an additional coat of paint applied to the edges, raised welds, outside corners and areas difficult to coat by spray before or after a full coat is applied to the surface.
442-4 Submittals
Submit the facilities quality control plan for process control that identifies the material stage, inspection ratio, production verification, inspection interval, minimum acceptable level of quality, quality control verification documentation, and work schedule. Submit blast media certifica tes of conformance in accordance with the requirements of SSPC AB -1 and or SSPC AB-3 as supplied by the abrasive supplier or the laborat ory, including results of testing to substantiate the certification. Submit Department test reports for each batch of paint to be used on the project , product data sheets and SDS sheets for paint and solvents used. Submit repair procedures conforming to the coating manufacturer’s written recommendations for the Owner’s approval. Repairs to the final coat must result in acceptable, uniform gloss and color on visible surfaces. The Owner shall have final authority concerning the coating’s uniformity and acce ptable appearance. These submittals may be generic in nature to address in- process non- conforming findings and should address at a minimum the following conditions: excessive surface profile, excessive millage, low millage, pinholing, runs, drips, sags, cu rtains and physically damaged areas. All repair procedures shall comply with the requirements of SSPC PA -1 and SSPC PA -2 as applicable and distinguish between localized (one square foot or less) and non -localized areas.
442-5 Protection of Work
Protect all parts of the structure against disfigurement by splatters, splashes, overspray and smirches of paint or of paint materials. Assume responsibility for any damage or disfigurement caused by operations to vehicles, persons or property, including plants and animals; and provide protective measures to prevent such damage. Thoroughly clean and restore any surface or surfaces disfigured by splatter, overspray, splashes, smirches or other defects to its orig inal condition. Restore any damaged structure or surface to its original condition. If traffic dust or other airborne particulates originating from earthen and/or gravel shop floors, abrasive blasting equipment and/or as determined by the Engineer is considered to be detrimental to the work; the shop shall take necessary precautions to prevent the accumulation of dust and dirt on blasted and freshly painted surfaces.
442-6 Quality Control (Qc)
Shop and field applicators are required to conduct and document quality control inspection of the painting, including measurements of temperature, dew point, surface profile and paint thickness. Quality control personnel shall have access to applicable proje ct specific requirements applicable to the coating system being applied. Personnel performing or overseeing the QC tests for this work shall be qualified in accordance with the Structural Steel Shop Coatings Program . All referenced standards outlined in t he Structural Steel Shop Coatings Program including appendices (as determined by the Engineer) are considered mandatory for shop and field applications.
442-7 Surface Preparation
A.Blast Cleaning The blas t profile shall be angular and between 1.0 and 3.0 mils when measured on a smooth steel surface. The degree of cleaning required shall be SSPC SP- 10 unless otherwise noted. SSPC VIS-1 shall be used as a visual standard. I n any dispute, the written defini tion set
4-62 forth i n the SSPC SP- 10 standard shall take precedence over reference photographs and
comparators shown in SSPC VIS -1. Check abrasives daily for contaminants or as otherwise directed by the Engineer. Prior to any surface preparation the Quality Control inspector shall verify that abrasive material meets the cleanliness requirements of SSPC AB -1, SSPC AB -2 and or SSPC AB -3 depending on the abrasive material used. Blast clean by centrifugal or forced air blasters. When using forced air blasters use blast nozzles with a minimum 5/16" orifice and operate at no less than 100 psi when measured with a needle gauge at the nozzle. Use dry blasting for all blast cleaning. Select a size or grade of abrasive that provides the specified finish and profile meeting Article 1080- 12. Perform blast cleaning operations so no damage is done to partially or entirely completed portions of the work . After blasting, brush the surface with clean brushes made of hair, bristle or fiber; blow off with compressed air; or clean by vacuum so any traces of blast products from the surface and any abrasive from pockets and corners are removed. Perform s urface inspection once all blast abrasive and dust is removed from surface to be coated. Use compressed air for nozzle blasting that is free of detrimental amounts of water or oil. Provide adequate separators and traps. Verify cleanliness of air before b lasting operations in accordance with ASTM D4285. Examine the blast cleaned surface for any traces of oil, grease or smudges deposited in the cleaning operations. If present, remove them by SSPC SP- 1 or an approved method. Ensure the degree of cleanliness and profile are approved by the Engineer before painting. Verify the removal of oil and grease in accordance with ASTM F22. Seal all journals, bearings, motors and moving parts to the Engineer’s satisfaction against entry of abrasive dust before blast cleaning near bridge machinery. Prime all blast cle aned surfaces to be painted no later than 8 hours after blast cleaning is complete. Re- clean the cleaned surfaces that contain rust or are contaminated with foreign material before painting or bolting to the original surface preparation specifications.
B.Hand or Power Tool Cleaning Thoroughly remove loose paint, rust, scale, dirt, oil, grease and other detrimental substances by hand cleaning (SSPC SP -2), power tool cleaning (SSPC SP -3) or any combination of these methods. Hand cleaning includes the use of m etal brushes, grinders, sanders or any approved combination of these tools. Use bristle or wood fiber brushes to remove loose dust.
442-8 Paint Systems
Department approved paint systems are found in the Structural Steel Shop Coatings Program . Use all paints and solvents for shop and field application that are produced by the same manufacturer. Use approved/qualified paint products found in Section 1080. Apply the pai nt system required by the plans .
442-9 Application of Paint
A.General Unless otherwise permitted, apply all paint by spraying, except apply the stripe coat by brush or roller. The use of a brush or roller is permitted to make minor re pairs to the primer. Make sure each coat of paint is in a proper state of cure or dryness before applying the succeeding coat.
4-63 Before successive coating application remove all contaminates, dry spray/overspray, paint
splatter and other non- adherent paint s hall be removed before applying successive coating layers. When necessary, clean each coat of paint in accordance with Subarticle 442-7(B). When a stripe coat is required, apply a 2 inch stripe by brush or roller to all exposed edges of steel before apply ing the finish coat. Locate the edge or corner in the approximate center of the paint stripe. Mechanically or hot dip- galvanized fasteners that exhibit damage during installation or coating operations shall be spot primed with a Department approved zinc r ich coating compatible with subsequent coatings. If personnel performing the coating operations does not exhibit reasonable conformance to protect the work during application, storage and/or construction, the Engineer may require a finish coat at no additi onal cost to the Department. The final acceptances of all repairs, to include aesthetics, will be approved at the Engineer’s discretion.
B.Application Conditions Unless the paint manufacturer's application instructions are more restrictive, obtain written permission to apply paint if the following conditions exist: temperature of the air or metal is not at least 40°F and rising for inorganic zinc primers or 50°F and rising for acr ylic paint or coal tar epoxies, w hen freezing weather is forecast during the drying period, or when the metal is hot enough to cause the paint to blister or produce a porous paint film. Do not apply paint or perform any surface preparation without the Engineer’s approval when the air is misty; in the rain, snow, fog, when wind velocity is continuously greater than 10 mph or when the steel surface temperature is less than 5°F above the dew point. The humidity shall be less than 85% and low er when applying acrylic paints or until the paint is dry and/or cured or until weather conditi ons permit its exposure in the open. Obtain written permission from the Engineer to apply field coats of paint between November 15 of one year and April 15 of the following year inclusive. Do not apply any coating above or below the manufacturers recommended application temperatures or during a period when an ambient temperature outside the recommended range is predicted during the drying and curing period of the paint. Harsh environments as determined by the Engineer may necessitate recleaning during or between paint applications.
C.Storage Conditions Provide adequate and safe storage for all paint and equipment. Do not expose paint materials to rain, excessive condensation, long periods of direct sunlight or temperatures above 110°F or below 40°F. Follow the manufacturer's storage requirements if more restrictive. In addition, the Quality Control inspector shall place a device which records the high, low and current temperatures inside the storage location and maintain a daily record and made available to the Engineer. Replace paint damaged by any cause. Coating material shall arrive at the coating facility in sealed containers clearly marked with the type, batch and/or lot numbers properly labeled on the container. There shall be no modification of the coating except upon and in accordance with the express written stipulation by an authorized representative of the coating manufacturer and with specific approval of the Engineer. At the Department’s option, the inspector may randomly collect a sample of the coating used on the project if the material has been exposed to extremely high/low temperatures and/or exhibits exces sive skinning in the container.
D.Mixing Paint Mix paint in accordance with the manufacturer's instructions and Article 1080 -1. Do not mix partial kits.
4-64 (E) Thinning
Thinning of zinc and coal tar products shall be in accordance with the coating manufacturer’s recommendations. For acrylic applications, there shall be no thinning of coating products. The paint products specified in Section 1080 do not require thinning when applied under normal conditions. Obtain written approval for any thinning necessitated by weather conditions or other causes. Only those thinners approved by the paint manufacturer as described in t he application instructions are permitted.
F.Spray Application Use equipment for spray application of paint that is suitable for the intended purpose, capable of properly atomizing the paint, and equipped with suitable pressure regulators and gauges. Use ai r caps, nozzles and needles recommended by the manufacturer of the equipment for the material being sprayed. Keep the equipment in satisfactory condition to permit proper paint application. In closed or recirculating paint spray systems where gas under pressure is used over the liquid, use an inert gas, such as nitrogen. Provide and drain periodically during operations. Use adequately sized traps or separators to remove oil and water from the compressed air. Make sure that the air from the spray gun impi nging against the surface shows no water or oil. Use a continuously agitated spray pot. Adj ust the agitator to reach within 2 inches of the bottom of the spray pot and be in motion at all times during paint application. Provide sufficient motion to keep the paint well mixed.
G.Stripe Coat When a stripe coat is required, apply a 2 inch stripe by brush or roller to all exposed edges of steel before applying the finish coat. Locate the edge or corner in the approximate center of the paint stripe. Brush apply stripe coat application on bolts, nuts, raised welds and other obstructed locations. Roller apply stripe coat only on structural shape edges.
442-10 Shop Painting
Shop painting is the painting of structural steel in an enclosed shop or plant before shipment to the site of erection. Use only NCDOT approved shop coating facilities meeting the requirements outlined in the current edition of the Structural Steel Shop C oatings Program . This program is available on the Materials and Tests website. The work in this section applies to previously uncoated steel and includes the proper preparation of the metal surfaces and the application, protection and cure/drying of coati ngs. Complete all shop fabrication, including welding and attachment of shear connectors, before painting is started.
442-11 Thermal Sprayed Coatings
Thermal sprayed coatings (TSC) and sealer are those coatings applied to metal surfaces in a shop environment. Use only NCDOT approved shop coating facilities meeting the requirements outlined in the current edition of the Thermal Sprayed Coatings (Metallization) Program . This program is available on the Materials and Tests website. Connection angles, plate washers , piles and other steel components that have been thermal spray coated (metallized) with aluminum that will be used on a concrete bridge shall have a barrier coat applied to the faying surfaces an d edges of those steel components coming into contact with concrete. Surface preparation and barrier coat paint systems are found in the Thermal Spray Coatings (Metallization) Program .
442-12 Field Painting
A.General Field painting is conducted after erection, or when damage to a shop applied coating system is repaired or when steel is otherwise painted outside an enclosed shop environment. The
4-65 Structural Steel Shop Coatings Program shall be considered in conjunction with the Project
Special Provisions for field applications. Preconstruction meetings as determined by the Engineer may be required prior to beginning field painting operations. When blast cleaning structures open to t raffic, provide suitable protective enclosures to prevent damage to public and private property. Do not blast directly over traffic without prior approval of the Engineer. If the containment system is not effective in restricting blasting emissions, blas ting operations shall cease and deficiencies corrected before work resuming.
B.Submittals Prior to beginning work, the Contractor shall furnish the Engineer for review and approval a containment plan for bridge washing, coating inspection plan, bridge protec tion plan, surface preparation and coating operations. Dispos al of construction materials to include but not limited to paint products, abrasives and wash water shall be in accordance with all current Federal and State regulations. Refer to NCDOT Guidelin es for Managing Bridge Wash Water . Do not apply paint over traffic without prior written approval from the Engineer. Touch- up of painted steel consists of painting with primer and finish paint over all the previously uncoated exposed metal surfaces . When the repair area exceeds one square foot, clean, prime and topcoat damaged areas in accordance with Subarticle 442 -7(A); otherwise , clean, prime and topcoat damaged areas in accordance with Subarticle 442 -7(B). For systems with shop applied topcoats, apply an additional field appearance coat of finish paint to the outside surface of all exterior beams on steel bridges over highways a nd navigable waterways. When an appearance coat of finish paint is required, paint the portion of galvanized high strength bolts on the outside face of exterior beams or girders with primer and appearance coat of the finish paint. Apply the primer to the galvanized high strength bolts by brush, so the primer is not applied to the adjacent finish paint. At the location of field welds, satisfactorily remove all paint or galvanizing in accordance with SSPC SP- 6 (Commercial Blast Cleaning) or SSPC SP -11 (Power Tool Cleaning to Bare Metal). The surface profile after cleaning and prior to coating application shall be a minimum of 1.0 mil. Clean all contaminants such as soil, concrete, weld splatter, grease or any other deleterious material from bare steel, shop or field coated surfaces before coating operations begin, during coating operations and after the coating is complete . Harsh environments may necessitate re- cleaning during or between paint applications.
C.Certification SSPC QP- 1 certified contractor shall perform work that is not associated with Hazardous Coating Removal operations.
D.Quality Control Field applicators are required to conduct and document quality control inspection as specified in Article 442 -6. Personnel performing the QC tests for this work shall possess one of the following minimum qualifications of an Association for Material s Protection and Performance ( AMPP) Basic Coating Inspector certification , SSPC Bridge Coating Inspector (BCI) Level I certification , the Department’s Bridge Coating Inspection Level I certification or show experience and/or competency in performing these duties .
4-66 Quality Control inspectors are required to maintain and record inspections that are required
by the contract and as outlined in the Structural Steel Shop Coatings Program . These record s shall be available for review and submitted to the Engineer or their representative at the end of each work week or as directed.
442-13 Preparation for Painting Galvanized Surfaces
When painting galvanized surfaces is required in the plan s, smooth, clean and prepare in accordance with Section 1080 and this section. Provide shop certification in accordance with Structural Steel Shop Coatings Program (Shop facilities that are currently certified and in good standing with the American Institute Steel Construction (AISC) /Sophisticated Paint Endorsement (SPE) and/or the Society of Protective Coatings (SSPC) Qualification Procedure Three (QP-3). Do not paint portions of galvanized piles encased in concrete below ground. Prior to coating operations submit for review and approval to the Engineer the specific procedure to be utilized for this work. This procedure at a minimum shall address the surface preparation outlined below and meet the ASTM D6386 standard. Smooth high spots and rough edges, such as metal drip lines, of galvanized surfaces in accordance with ASTM D6386. Clean galvanized surfaces to be painted with a 2,500 psi pressure w asher. Allow surfaces to dry completely before beginning surface preparation. Prepare galvanized surfaces to be painted by sweep blasting in accordance with ASTM D6386. Use an abrasive material and technique that roughens the surface while leaving base zinc layers intact. After sweep blasting, blow down blasted surfaces with clean, dry, compressed air free of contamination. Apply paint to clean, dry surfaces free of visible zinc oxides or zinc hydroxides within 8 hours of sur face preparation.
442-14 Repainting of Existing Steel Structures
A.Pollution Control During field painting operations, use all necessary precautions to prevent dispersion of surface preparation debris, paint or any other material outside the work area due to wind or any other reason.
B.Hazardous Paint Removal Should the existing paint system include toxic substances such as red lead oxide , which is considered hazardous if improperly removed, furnish a containment and spill control plan for surface preparation and painting operations and await review and approval of said plan before beginning work. This plan shall meet Class 2A in accordance with SSPC Guide 6. This work shall be performed by a SSPC QP -2 certified contractor. Monitor air quality. Any visible emissions outside the containment structure or air quality monitoring results exceeding the permissible OSHA action level are justification for suspension of the work. Monitor air quality at random locations within 1 foot to 5 feet from the enclosure in accordance with National Institute of Occupational Safety and Health (NIOSH) Method 7082. Immediately collect and retain an y spilled dust or paint debris in approved containers. If a spill results in soil or water contamination, take all necessary actions to remediate the site to its original state.
C.Waste Handling Clean and dispose of any incidental material or equipment that is contaminated as the result of work performed .
Source: North Carolina Standard Specifications for Roads and Structures, 2024 Edition. Pages 196–202 of 857.