Driveway Addition



The need for additional parking space forced us to add on a side slab for a compact car.

In addition, we needed to provide better drainage for the area.

A lot of excavation was required to provide for a 4 inch slab over a couple inches of 1" wash gravel sub strata.

Drive addtion drains to the right, will have 6 inch grates and water removal that will hook into a French Drain system that will take water to back of property and enter the open concrete water drain system.


Visible wire is the phone service line. It will be covered by the slab.

Excavation included removal of over 50 wheelbarrow loads of dirt. Dirt was stored in back yard and will later provide for back fill in the French drain system.
A quick deluge filled the hole within 24 hours after final excavation. It took 2 days to empty. So, rather than wait for the slab, the drainage system became a priority.
Here is the trench, lined up with the right side of the slab, where the drain grate will run.
Water on the slab will run off to the east and fall into the grate. The channel grate comes in one meter lengths.
The grate connects to the drain box via PVC. The line running off to the west is for future development, in the event we put a grate across the existing driveway.
The run from the drain box is 4 inch corrugated drainage pipe that after connecting with the two lines from the neighbors yard to the east will convert to sleeved, perforated French drain pipe.
Rebar (1/2 inch x 10 feet) was put in a grid on 18" centers.
Rebar seats were used to help hold the rebar off the substrata. Holes were drilled in the forms to provide enhanced strength at the end of the rebar.
George and Ben screeding the concrete level. The concrete was 4000 psi.
Slab is poured. We were 1/3 cubic yd short...had to get another yard delivered. The rock content, the delay, and the heat all contributed to a difficult floating process.
Slab was wetted and covered for curing.
The 4 sections of the grates were glued together with PVC solvent and were placed in the trench. Wire hooks held the unit in place as well as pounded rebar anchors. Then the grate system was attached to the 12 x 12 catch basin by means of 3 inch PVC.
A plastic barrier was placed along the grating to reduce erosion and then dirt was backfilled.

The trench system was finished off with silicone caulk between the edge of the slab and the grate and between the grate and the plastic strip.

Water runoff from the driveway now has a path over 125 feet to the concrete drainage channel behind the property.


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