7.50 SODDING
Shape Sodbed
Ditch channels should be shaped in order to obtain a relatively level, flat-bottom
ditch which will drain without water ponding. The depth should be a minimum of 150 mm
(6 inches) below adjacent ground. Many ditch failures result because the ditch bottom is
not level, causing a concentration of flow on one side of the ditch.
Apply Fertilizer
The first application of fertilizer shall be applied prior to laying of sod.
Fertilizer must be spread with a mechanical spreader at a uniform rate of application.
A cyclone seeder may be used.
Place Sod
Note the quality of sod, making sure it is free of objectionable material (tree
roots, brush, stones, etc.) also that it is free of noxious weeds and relatively
free of all other weeds and grasses other than bluegrass. The sod is to be mowed to
a height of 40 to 50 mm (1 1/2 to 2 inches) prior to cutting. On the sides and bottoms
of ditches and channels, strips must be laid at right angles to the centerline of the
channel.
The project engineer may order areas staked to prevent loss of sod before the root system becomes established. Staking of sod channels ordered by the project engineer is paid for at 25 percent of the contract price for sodding.
Sod can be placed until the ground freezes at the construction site or at the sod farm.
Finish Sod
Smooth disturbed areas along the edges of the sod. Be sure that no ridge of dirt remains
along side the sod ditch, and that the disturbed area is properly shaped and sloped to allow
water to run onto the sod.
Seed
Reseed disturbed areas, using the seed mixture specified.
Mulch
Mulch disturbed areas, using the mulch rate specified.
Water
Water the sod within one hour after laying, and thereafter as specified. The amount
of water required for sodding varies depending upon soil type, soil moisture, and local
weather conditions at the time of sodding. Watering is to saturate the soil to a depth
of 100 mm (4 inches) or a maximum of 40 L/m2 (100 gallons of water per 100 square
feet). Sod should be watered with a spray, and not much pressure. Too much pressure disturbs
the sod and has a tendency to wash the dirt away from its edges. All areas disturbed in
preparation of sod ditches must be watered with the sod after seeding, fertilizing, and
mulching.
Tamp
Tamp or roll sod as specified if necessary to secure bonding.
Special Ditch Control
Place special ditch control over the sod when specified. This material is normally specified
on steep ditch grades, and at the outlet end of roadway pipes where large volumes of runoff water
may occur.
7.51 PAYMENT
If the contractor fails to maintain the sod as specified above, washed out sod must be replaced at the contractor's expense.