732 Page 489732 MULCHING
732.1DESCRIPTION
This work consists of placing a mulch cover on slopes or other designated areas following seeding and fertilizing operations.
732.2MATERIALS
A.Grass Hay or Straw Mulch: Grass hay or straw mulching material will be free of noxious weed seeds and objectionable foreign matter. The mulch will have been baled dry, in bales of approximately equal weight and will be relatively dry when applied. Materials with noxious weed contamination or materials with characteristics unsuitable for the purpose intended will be rejected and the Contractor will remove the contaminated material from the project. Bromegrass is not an acceptable mulch. B.Fiber Mulch: Fiber mulch will contain no germination or growth inhibiting factors and will have the property of becoming evenly dispersed and suspended when agitated in water. Fiber mulch that is blended with recycled paper is not allowed. When sprayed uniformly with hydraulic seeding equipment on the surface of the soil, the fibers will form a blotter like ground cover, which will readily absorb water and allow infiltration to the underlying soil without restricting emergence of seedlings. Weight specification from suppliers, and for all applications, will refer only to air dry weight of the fiber, considered to be 10% moisture. The fiber mulch material will be supplied in packages marked by the manufacturer to show the air dry weight content. Suppliers will certify that laboratory and field testing of their product has been accomplished, and that it meets all of the foregoing requirements. C.Bonded Fiber Matrix: Bonded fiber matrix will consist of a continuous layer of elongated fiber strands held together by a water resistant bonding agent. The bonded fiber matrix will be uniformly applied and will have no gaps between the product and the seeded soil. The product will be 100% biodegradable and composed of 90% wood fiber, 9% natural binder, and 1% organic and mineral activators (all by weight). The treatment will be installed with hydraulic seeding equipment. D.Fiber Reinforced Matrix: Fiber reinforced matrix will consist of thermally processed fiber, crimped interlocking fibers, cross-linked hydrocolloidal polymer tackifiers, and activators. Fiber reinforced matrix will form an intimate bond with the soil surface. The fiber reinforced matrix will form a continuous, flexible, and lofty interlocking matrix that creates air spaces and water absorbing cavities to improve seed germination, reduce the impact of raindrop energy, and minimize soil loss. The treatment will be installed with hydraulic seeding equipment.
732.3CONSTRUCTION REQUIREMENTS
During mulching operations, suitable warning signs will be provided in accordance with Section 5.14. 732 Page 490A.Grass Hay or Straw Mulch: 1.Placing: The mulch will be placed within 48 hours after the seeding has been completed. Mulching operations will not be performed during periods of high winds, which preclude the proper placing of the mulch. The placing of mulch will begin on the windward side of the areas to be covered. The mulch will be machine blown to uniformly distribute mulch over the seeded areas. The machine will blow or eject mulch, by a constant air stream, that controls the amount of mulch. The machine will cause a minimum of cutting or breakage of the mulch. Mulch containing excessive moisture, which prevents uniform feeding through the machine, will not be used. Mulch will be placed uniformly over the seeded areas at a rate of 2 tons per acre. Approximately 10% of the soil surface will be visible through the mulch blanket prior to mulch tiller (punching) operation. Excessive cover, which will smother seedlings, will be avoided. The Engineer may order the placement of mulch on any area where protection is necessary to forestall erosion or encourage turf establishment. 2.Punching: Immediately following application, the mulch, will be punched into the soil by a mulch tiller consisting of a series of dull, flat disks with notched or cutout edges. The disks will be approximately 20 inches in diameter, 1/4 inch thick, spaced approximately 8 inches apart and fitted with scrapers. Working width of the tiller will not exceed 6 feet per member but may be operated in gangs of not over three members. The tiller will be operated on contour, except those on slopes 3:1 or steeper diagonal operation will be permitted. Tiller members will be ballasted; to push mulch into the soil approximately 3 inches with ends exposed above the soil surface. The mulch tiller will follow as closely as possible behind the mulcher. Mulch will not be blown when wind velocity causes appreciable displacement before it can be anchored by the mulch tiller. More than one pass of the mulch tiller may be required to ensure adequate anchoring. B.Fiber Mulch: Rate of application will be 2,000 pounds per acre unless otherwise specified in the plans or by the Engineer. Excessive thickness of mulch, which will smother grass seedlings, will be avoided. Mulch will be placed on a given area as soon as possible or within 48 hours after seeding as a separate operation. The Contractor will allow the fiber mulch to cure a minimum of 18 hours prior to watering. C.Bonded Fiber Matrix: Rate of application will be 3900 pounds per acre and the mix will consist of 50 pounds bonded fiber matrix to 125 gallons water unless otherwise specified in 732 Page 491the plans or by the Engineer. Bonded fiber matrix will be placed on a given area as soon as possible, or within 48 hours after seeding as a separate operation. D.Fiber Reinforced Matrix: Fiber reinforced matrix will not be placed in channels. Fiber reinforced matrix will be placed on a given area as soon as possible and within 48 hours after seeding as a separate operation. Fiber reinforced matrix is effective upon application therefore does not require a curing time. E.Care during Construction until Acceptance of Field Work: Traffic, either foot, equipment, or vehicle will be avoided over the seeded and mulched areas. Before the Acceptance of Field Work is made by the Area Office, any area on which the original mulch has been displaced will be remulched.
732.4METHOD OF MEASUREMENT
A.Grass Hay or Straw Mulch: Grass hay or straw mulching material will be measured to the nearest 0.1 ton of mulch applied. Reapplication in areas damaged from causes beyond the control of the Contractor will be measured and added to the original quantities used. B.Fiber Mulch: Fiber mulch will be measured to the nearest pound or 0.1 ton, as specified in the plans, of mulch applied. Reapplication in areas damaged from causes beyond the control of the Contractor will be measured and added to the original quantities used. C.Bonded Fiber Matrix: Bonded fiber matrix will be measured to the nearest pound or 0.1 ton, as specified in the plans, of matrix applied. Reapplication in areas damaged by means beyond the control of the Contractor will be measured and added to the original quantities used. D.Fiber Reinforced Matrix: Fiber reinforced matrix will be measured to the nearest pound or 0.1 ton, as specified in the plans, of matrix applied. Reapplication in areas damaged by means beyond the control of the Contractor will be measured and added to the original quantities used.
732.5BASIS OF PAYMENT
A.Grass Hay or Straw Mulch: Grass hay or straw mulch will be paid for at the contract unit price per ton. Payment will be full compensation for furnishing, hauling, placing, punching, and for materials, equipment, labor, tools, and incidentals necessary. B.Fiber Mulch: Fiber mulch will be paid for at the contract unit price per pound or ton, as specified in the plans. Payment will be full compensation for furnishing, hauling, and placing and for materials, equipment, labor, tools, and incidentals necessary. C.Bonded Fiber Matrix: Bonded fiber matrix will be paid for at the contract unit price per pound or ton, as specified in the plans. Payment will be full compensation for furnishing, hauling, and placing and for materials, equipment, labor, tools, and incidentals necessary. D.Fiber Reinforced Matrix: Fiber reinforced matrix will be paid for at the contract unit price per pound or ton as specified in the plans. Payment will be full compensation for furnishing, hauling, and placing and for materials, equipment, labor, tools, and incidentals necessary. 733 Page 492733 SODDING
733.1DESCRIPTION
This work consists of preparing the ground surface and furnishing, transporting, placing, and fertilizing live sod.
733.2MATERIALS
The sod will consist of a dense, well rooted growth of Kentucky bluegrass or other specified grass native to the general locality of the project. The sod will be free from noxious weeds, objectionable grasses, weeds, and foreign materials. Peat sod will not be allowed. At the time the sod is cut, the grass will have a length of approximately 2 inches if longer than 3 inches, the grass will be cut to approximately 2 inches in length and the sod will have been raked free of debris. If the sod is in a dry condition so that it cannot be cut, rolled, loaded, and hauled to the job site, without crumbling or breaking, water will be applied in sufficient quantity to provide a well moistened sod to the depth to which it is to be cut. Water used on sod will be from municipal, domestic, or other sources known to be suitable for irrigation.
733.3CONSTRUCTION REQUIREMENTS
A.Cutting Sod: Sod will be machine cut into rectangular sections. The sections will be of uniform width. The sod will be cut to a depth of 3/4 inch or more so the dense root system will be retained and exposed in the bottom side of sod, and the sod can be handled without undue tearing or breaking. Sod will be rolled with the top growth inside. Sod strips which indicate crumbling, tearing, breaking, or loss of soil during the operations of cutting, transporting, or handling will not be acceptable. Sod will be laid in its final position within 36 hours after being cut. During the period between cutting and laying, the sod will be protected from damage. B.Preparing Surface for Sodding: The surfaces to be sodded will be constructed to the required cross section and contour and will be smooth, uniform, and free from stones, roots, and other undesirable foreign material. The surfaces will be undercut to sufficient depth below adjacent areas so the top of newly laid sod will be flush with any adjacent seeded or turfed areas and 1 inch below top of sidewalks, curbs, and other structures. Some trenching in of the areas to be sodded and some building up of the adjacent areas may be necessary. The adjacent areas will smoothly blend with each other, without sharp breaks in the contours. Immediately prior to placing the sod, the soil will be loosened and brought to a fine granular texture, to a depth of not less than 1 inch. Clods, lumps, weeds, rocks larger than 3/4 inch, and other undesirable materials will be removed. If the ground prepared for sodding is dry or hot, prewatering of the earth bed to a depth of 1 inch may be required prior to sodding. The earth bed will be allowed to dry sufficiently after watering to permit sod placement without tracking.