(1) Drainage. All parking lots shall be designed and constructed so that no surface run-off will drain across a sidewalk, bike path, driveway or walkway within a public right-of-way. Surface run-off is permitted to drain into an adjacent alley, if the alley has an existing storm drain system capable of handling the additional run-off. All run-offs shall be approved by the City Engineer.

(2) Base Material. Decomposed granite or 1"-0 crushed rock of a gradation approved by the city shall be used as base material. The base shall be compacted to a minimum of 95% of optimum density and shall exhibit a uniform grade in appearance. Unstable subgrade (soft spots) shall be removed and replaced with sub-base shale. Parking lot base material minimum thickness requirements are 4 inches of crushed rock or 6 inches of decomposed granite for asphalt surfaces and 2 inches of granite for concrete surfaces.

(3) Asphalt Surface. Asphalt surface lots shall be a 2 inch minimum thickness of level 2, ½” dense Asphalt Concrete Pavement (ACP) mixture. All bituminous and concrete surfaces in contact with the asphalt shall be sprayed with tack coat prior to asphalt placement.

Asphalt shall be a temperature of between 250 and 300 degrees F at the time it is placed. It shall be placed on dry prepared surfaces and when the air temperature in the shade is 35 degrees F or warmer. Placing during rain or other adverse weather conditions will not be permitted, except that material in transit at the time adverse conditions may occur may be placed provided it is of proper temperature, has been covered during transit, and is placed on a foundation free from pools or flow of water.

The asphalt shall be rolled immediately after the asphalt has been placed using a steel wheeled or pneumatic tired roller capable of transmitting sufficient force necessary to compact the material to 90%of optimum density. The finished surface shall be true to grade, free of irregularities and roller wheel marks.

(4) Concrete Surface. Concrete surface parking lots shall be a 6-inch minimum thickness of 3000-1-1/2 Portland Cement concrete. No concrete shall be placed when the ambient temperature is below 35 degrees F. Concrete subject to freezing temperatures during curing shall be adequately protected. The concrete shall be compacted using screens or tampers. The surface shall be finished as specified, with a uniform surface free from laitance, soupy mortar, marks or irregularities. Joints will be placed as specified on plans. When no specification is made, joints shall conform to Section 00756.48 of the Oregon Standard Specifications for Construction (OSSC). Immediately upon final surface finishing, the entire exposed surface of the newly laid concrete shall be covered and cured using a membrane-forming compound, impervious sheeting, or saturated mats for at least 72 hours.

Alternates to the above specifications may be approved by the City Engineer who shall inform the Building Safety Director of his approval.

(5) Permits.