SECTION 215 - MULCHING
215.01 Description. This work consists of furnishing, transporting, placing, and
anchoring vegetative mulch on slopes, shoulders, medians, and other designated areas. Mulching may be accomplished by hydraulically applying the mulch in accordance with these specifications.
215.02 Materials. The vegetative materials for mulch shall meet the requirements of
Subsection 715.05. It is intended that Type I Vegetative Materials shall be used when available. When it is determined by the Engineer that Type I Vegetative Material is not reasonably available, Type II Vegetative Material will be permitted as provided in Subsection 715.05, with the concurrence of the State Roadside Development Manager. Bituminous material for mulch shall be Emulsified Asphalt, Grade SS-1, meeting the requirement of Subsection 702.07. Subject to satisfactory results being obtained, this material will be accepted on a certification basis in accordance with Subsection 106.04.
215.02.1 Hydraulically Applied Mulch (Hydromulch). Fibers for hydromulch shall
be produced from wood, straw, cellulose, natural fibers, or recycled fibers that are free of non-biodegradable substances. The fiber shall disperse into a uniform slurry when mixed with water. Fibers shall be colored green, or other approved contrasting color, and shall not stain concrete or other surfaces. The use of tacifiers or activators will be allowed. Hydromulch shall be one from the Department’s APL.
215.02.1 1--Wood Fiber Mulch. Wood fiber mulch shall be made from wood chip
particles manufactured particularly for discharging uniformly on the ground surface when dispersed by a hydraulic water sprayer. It shall remain in uniform suspension in water under agitation and blend with grass seed and fertilizer to form a homogeneous slurry. The fibers shall intertwine physically to form a strong moisture-holding mat on the ground surface and allow rainfall to percolate the underlying soil. The fiber material shall be heat processed so as to contain no germination or growth-inhibiting factors. The mulch shall be dyed an appropriate color to facilitate the application of material using non-toxic dye.
215.02.1 2--Cellulose Fiber Mulch. Cellulose fiber mulch consists of recycled paper
stock products which are shre dded into small pieces par ticular for application by hydraulic seeding equipment. It shall mix readily and uniformly under agitation with water and blend with grass seed and fertilizer to form a homogeneous slurry. When applied to the ground surface, the material shall form a strong moisture-holding mat, allow rainfall to percolate the underlying so il, and remain in place until the grass root system is established. The material shall contain no growth inhibiting characteristic or organisms. The mulch shall be dyed an appropriate color to facilitate the application of material using non-toxic dye.
215.02.1 3--Wood/Cellulose Fiber Mulch . Wood/cellulose fiber mix hydroseeding
mulch shall consist of a combination of the above wood and cellulose fibers at a ratio recommended by the manufacturer of the products.
215.02.1 4--Straw Mulch. Straw mulch shall consist of a natural straw fiber. This
material shall be a minimum 90% straw and essentially free from plastic materials or other non-bio degradable substances. The material shall be dispersed into a uniform mulch slurry when mixed with water.
215.02.1 5--Tackifier. The tackifier will serve the purpose of an adhesive to form a bond
between the soil, fiber, and seed particles. It will also allow the soil to retain moisture. The tackifier shall be of the organic or synthetic variety.
215.03 Construction Requirements.
215.03.1 Equipment. Mulching equipment shall be capable of maintaining a constant
air stream that will blow or eject controlled quantities of mulch in a uniform pattern. If asphalt is used, a jet or spray nozzle for applying uniform, controlled amounts of asphalt to the vegetative material as it is ejected shall be located at or near the discharge spout. Mulch stabilizers shall consist of dull blades or disks without camber and approximately 20 inches in diameter. The disks shall be notched, shall be spaced at approximately 8- inch intervals, and shall be equipped with scrapers. The stabilizer shall weigh approximately 1000 to 1200 pounds, shall have a working width of no more than eight feet, and shall be equipped with a ballast comp artment, so that when directed weight can be increased.
215.03.2 Placement of Vegetative Mulch . Mulching shall be placed uniformly on
designated areas within 24 hours following seeding unless weather conditions are such that mulching cannot be performed. Placement shall begin on the windward side of areas and from tops of slopes. In its final position the mulch shall be loose enough to allow air to circulate but compact enough to partially shade the ground and reduce erosion. The baled material shall be loosened and broken thoroughly before it is fed into the machine to avoid placement of unbroken clumps.
215.03.3 Rates of Application and Anchoring Mulch . The Engineer will designate
the rate of application of vegetative mulch within the limits of one to two tons per acre. The mulch may be anchored by either the us e of a mulch stabilizer or by tacking with bituminous material. If a mulch stabilizer is used, the mulch shall be punched into the soil for a minimum depth of one inch. If bituminous material is used, the rate of application shall be 150 gallons per acre. Where steep slopes or other conditions are such that anchoring cannot be performed satisfactory with a mulch stabilizer, the Engine er will require the bituminous material be applied at the time or immediately following the mulch placement. When mulch stabilizers are used, anchoring the mulch shall be performed along the contour of the ground surface. As the work progresses, the Engineer will determine the actual rate of application of the vegetative mulch and the bituminous material, if used, on each area not to exceed three acres. For vegetative mulch, a tolerance of 15 percent will be permitted without correction. For bituminous material, if used , a tolerance of 10 percent will be permitted without correction. Areas deficient in application by more than these amounts shall be corrected by reapplication in a manner appr oved by the Engineer. For areas on which vegetative material has been placed in excess of the tolerance permitted, that portion of the material placed in excess of the tolerance allowed will be deducted from the measured quantities. In the event an excess of vegetative material has been placed in a quantity deemed by the Engineer to be undesirable, the Contractor shall remove and replace all material placed on that area at no additional cost to the State.
215.03.4 Protection and Maintenance . The Contractor shall maintain and protect
mulched areas until release of maintenance of the project. The Contractor shall take every precaution to prevent unn ecessary foot and vehicular tr affic and shall repair and restore immediately any displacement of mulch without extra compensation. At appropriate times determined by the Engineer, the Contractor shall mow or otherwise remove or destroy all undesirable growth on all areas mulched to prevent competition with the desired plants and to prevent reseeding of undesirable growth. All mowing shall be a part of protection and maintenance.
215.03.5 Hydromulch. Hydromulch shall be applied in accordance with the installation
instructions and recommendations of the manufacturer. Hydromulch shall be uniformly applied at the manufacturer’s recommended application rate. In no case shall the application rate be less than one (1) ton per acre.
215.03.5 1--Protection and Maintenance . The Contractor should maintain and protect
mulched areas until the Release of Maintenance of the project. The Contractor should take every precaution to prevent unnecessary foot and vehicular traffic. The Contractor should mow, remove or destroy any undesirable growth on all areas mulched as soon as any undesirable growth a ppears. This will prevent competition with the desired plants and to prevent reseeding of undesirable growth.
215.03.5 2--Hydro Equipment. The equipment for hydraulically applying seed and
mulch shall have a built-in agitation system with an operating capacity sufficient to agitate, suspend, and homogeneously mix slurry of the specified amount of fiber, seed, and water. The slurry distribution lines shall be large enough to prevent stoppage. The discharge line shall be equipped with a set of hydraulic spray nozzles, which will provide even distribution of the slurry on the various areas to be seeded. The mixture shall all be combined into the slurry tank for distribution of all ingredients in one operation as specified herein. The materials shall be combined in a manner recommended by the manufacturer. The slurry mixture shall be so regulated that the amounts and rates of application shall result in a uniform application of all materials at rates not less than the amounts specified. Us ing the color of the mulch as a guide, the equipment operator shall spray the prepared seedbed with a uniform visible coat. The slurry shall be applied in a sweeping motion, in an arched stream, so as to fall like rain, allowing the mulch to build upon each other until an even coat is achieved.
215.04 Method of Measurement. Accepted quantities of vegetative material for mulch
will be measured by the ton. The weight for measurement will be the product of the number of bales acceptably placed and the average weight per bale as determ ined on approved scales provided by the Contractor.
Mulching in other states
Get an email when 215 changes
Mississippi revises spec sections through supplementals and new editions. We check this one every week and email you the day it changes. Free, no account.