Item No. 602

Sodding for Erosion Control

602.1 Description

This item shall govern planting of Bermuda grass; St. Augustine or other acceptable grass sod at locations indicated on the Drawings or as directed by the Engineer or designated representative in accordance with this Standard Specification Item.

602.2  Submittals

The submittal requirements for this specification item shall include the identification of the type and source of sodding, the type of mulch, type of tacking agent and type and rate of application of fertilizer.

602.3  Materials 

A.  Block and Mulch Sod 

 

The sod shall consist of live, growing Bermuda Grass, St. Augustine grass, when shown on the Drawings, or other acceptable grass sod indicated on the Drawings secured from sources that are approved by the Engineer or designated representative.  Bermuda Grass sod, St. Augustine sod or other grass sod as shown on the Drawings shall have a healthy, virile root system of dense, thickly matted roots throughout the soil of the sod for a minimum thickness of 1 inch.  The thickness measure does not include grass.  The sod shall be cut in rectangular pieces with its shortest side not less than 12 inches.  The Contractor shall not use sod from areas where the grass is thinned out nor where the grass roots have been dried out by exposure to the air and sun to such an extent as to damage its ability to grow when transplanted. 

 

The sod shall be substantially free from noxious weeds, Johnson grass or other grasses and shall not contain any matter deleterious to its growth or which might affect its subsistence or hardiness when transplanted.  Unless the area has been closely pastured, it shall be closely mowed and raked to remove all weeds and long standing stems.  Sources from which sod is to be secured shall be approved by the Engineer or designated representative.

 

Care shall be taken at all times to retain the native soil of the roots of the sod during the process of excavating, hauling and planting.  Sod material shall be kept moist from the time it is dug until it is planted.  The sod existing at the source shall be watered to the extent required by the Engineer or designated representative prior to excavating.

 

 

 

B.  Fertilizer 

Fertilizer and the rate of application shall conform to the requirements of Standard Specification Item No. 606S, "Fertilizer".

C.  Mulch 

Straw mulch shall be oat, wheat or rice straw.  Hay mulch may be substituted for straw mulch and shall be Prairie Grass; Bermuda grass or other hay approved by the Engineer or designated representative.  The hay or straw mulch shall be free of Johnson grass or other noxious weeds and foreign materials.  It shall be kept in a dry condition and shall not be molded or rotted.

 

D.  Water 

Water shall be furnished by the Contractor and shall be clean and free of industrial wastes and other substances harmful to the growth of sod or to the area irrigated.

E.   Tacking Agents

Tacking agents for straw or hay mulch shall be as shown on the Drawings.

602.4  Planting Season

All planting shall be done between April and November except as specifically authorized in writing by the Engineer or designated representative.

602.5  Construction Methods

A.  General 

After the designated areas have been completed to the lines, grade and cross sections indicated on the Drawings, the surface shall be worked to a depth of not less than 4 inches with a disc, tiller or other equipment approved by the Engineer or designated representative.  Fertilizer nutrients shall be applied and tilled.  Areas that become crusted shall be reworked to an acceptable condition before sodding.  Sodding of the type specified shall conform to the requirements of this Specification Item.  The Contractor shall give continuous care to the sodded area until the sod is accepted.

 

B.  Placement 

The sod shall be placed on the prepared surface with the edges in close contact and alternate courses staggered.  In ditches the sod shall be placed with the longer dimension perpendicular to the flow of water in the ditch.  On slopes, starting at the bottom of the slope, the sod shall be placed with the longer dimension parallel to the contours of the ground.  The exposed edges of sod shall be buried flush with the adjacent soil.  On slopes exceeding 3:1 or where the sod may be displaced, the sod shall be pegged with not less than 4 stakes or ground staples per square yard with at least 1 stake or ground staple for each piece of sod.

 

Pegs shall be of wood lath or similar material, pointed and driven with the flat side against the slope, 6 inches into the ground, leaving approximately 1/2 inch of the top above the ground.  Ground staples shall not be less than 13 inches in length and shall be constructed of No. 11 gage wire that is bent to form a "U" approximately 1 inch in width.

 

C.  Watering 

Immediately after the area is sodded, it shall be watered with a minimum of 5 gallons of water per square yard and at 10 day intervals as needed and as directed by the Engineer or designated representative.  Subsequent to the initial application water shall be applied at a minimum rate of 3 gallons per square yard, as required on the Drawings or as directed by the Engineer or designated representative until final acceptance by the City or until the grass uniformly reaches a height of 2 1/2 inches.

 

D.  Finishing

 

Where applicable, the shoulders, slopes and ditches shall be smoothed after planting has been completed and shaped to conform to the desired cross sections shown on the Drawings.  Any excess soil from planting operations shall be spread uniformly over adjacent areas or disposed of as directed by the Engineer or designated representative so that the completed surfaces will present a neat appearance.  All sodded areas shall be rolled after the initial watering application, when sufficiently dry.

602.6  Block Sodding

At locations indicated on the Drawings or where directed by the Engineer or designated representative, sod blocks shall be carefully placed on the prepared areas.  The fertilizer shall then be applied in accordance with the applicable provisions of Item No. 606S, "Fertilizer" and thoroughly watered.  When sufficiently dry, the sodded area shall be rolled or tamped to form a thoroughly compacted, solid mat.  Any voids left in the block sodding shall be filled with additional sod and tamped.  Surfaces of block sod which, in the opinion of the Engineer or designated representative may slide due to the height and slope of the surface or nature of the soil, shall be pegged with wooden pegs driven through the sod blocks into firm earth sufficiently close to hold the block sod firmly in place.  Edges along curbs and drives, walkways, etc., shall be carefully trimmed and maintained until the sodding is accepted.

602.7  Mulch Sodding 

The sod source shall be disked in 2 directions cutting the sod thoroughly to a depth of not less than 4 inches.  Sod material shall be excavated to a depth of not more than 2 inches below the existing root system, being careful to avoid having soil containing no grass roots.  The disked sod may be windrowed or otherwise handled in a manner satisfactory to the Engineer or designated representative.  The material shall be rejected if not kept in a moist condition.

 

Prior to placement of mulch sod, the cut slopes shall be scarified by plowing furrows 4 inches to 6 inches deep along horizontal slope lines at 2 foot vertical intervals.  Excavated material from the furrows shall not protrude more than 3 inches above the original surface of the cut.  Fertilizer shall be distributed uniformly over the area in accordance with the applicable provisions of, "Fertilizer".  The sod shall then be deposited upon the prepared area and spread uniformly to the thickness indicated on the Drawings.

 

Any section that is not true to lines and cross sections shall be remedied by the addition of sod material or by reshaping the material to meet the requirements of "Finishing".  After the sod material has been spread and shaped, it shall be thoroughly wetted and compacted with a corrugated roller of the "Cultipacker" type.  All rolling of slope areas shall be on the contour.

602.8  Measurement

Work and acceptable material for "Sodding for Erosion Control" will be measured by the square yard complete in place with a minimum of 95 percent growth with a 2 1/2 inch stand of grass.

602.9  Payment

Work performed under this item will be considered subsidiary to other items of work unless a sperate bid item is provided in the contract documents, then work performed and materials furnished and measured as provided under "Measurement" will be paid for at the unit bid price for Bermuda Block Sodding", "St. Augustine Block Sodding", "Bermuda Mulch Sodding" or "Other Approved Grass Sodding".  The prices shall each represent full compensation for completion of the work including all water applications, rolling, pegging and fertilizer as indicated on the Drawings.

 

Payment will be made under one of the following:

 

Pay Item:                            Bermuda Block Sodding -                           Per Square Yard.

Pay Item:                            St. Augustine Block Sodding -                    Per Square Yard.

Pay Item:                            Bermuda Mulch Sodding -                          Per Square Yard.

Pay Item:                            Grass Sodding -                                          Per Square Yard.

 

 

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