Ward Construction provides services in the greater San Francisco Bay Area specifically, Alameda, Contra Costa, Marin and Solano Counties. Our coverage includes Oakland, Berkeley, Richmond, Walnut Creek, Lafayette, Orinda, Moraga, Hayward, Marin and other East Bay and North Bay cities.
Here’s an example of the type of services provided:
We will construct a sub-drain 3 feet deep and 75 feet long on the slope above the residence.
The drainage system consists of a perforated pipe in a rock filled trench to collect sub-surface water. At the upper end or start of the line a clean-out will be provided so that the line can be tested or cleaned as necessary.
The minimum depth for the perforated pipe will be below the grade of soil under the house while falling at least 1/8 inch per foot for the total length of the system to the point of discharge.
The perforated pipe will be installed on top of a bed of gravel, two inches deep, with the perforations pointed down. The trench will then be backfilled with drain rock. The rock is Class I, Permeable Type A drain rock per the California State Specifications. The drain rock is clean gravel that varies in size from 1/4 to 1/2 inch. This size rock works best for our type of soil in that it allows the maximum amount of water to penetrate quickly and is small enough to keep out most of the surrounding soil.
The trench will be a minimum of 12 inches wide. This permits a four inch blanket of rock on each side of the four inch perforated pipe. If the trench that holds the drain is not wide enough, the drain rock will soon become impregnated with dirt from the sides of the trench and will not allow the water to reach the drain pipe.
The system will discharge through a 6 inch solid pipe down the slope to the existing natural drainage ravine.
All spoils will be left rough graded on site. Contractor assumes no responsibility for the spoils after the job is completed.
The landscaping plants and bushes will be removed and not replaced along the path of the drain.
