New Asphalt Driveway Installation in Portland, Oregon

Installing a New Driveway in Portland

A new asphalt driveway in Portland is a straightforward project when it is done right — and a recurring headache when it is rushed. The difference comes down to base preparation for Multnomah County's clay soils, getting the right-of-way approach permitted and built to City standards, and paving within the dry-weather window Portland's wet climate allows. This guide walks through what installing a new driveway here actually involves, from the first cut of excavation to the cure.

Whether you are paving bare ground for the first time or replacing an old surface, understanding the process helps you ask better questions and recognize a quality job. For the detailed mechanics, see our step-by-step installation process, and for the big picture, the complete Oregon asphalt driveway guide.

The Installation Process, Step by Step

1. Layout and Excavation

The crew marks the driveway's dimensions and excavates to the depth needed for base and asphalt — commonly several inches below finished grade. Topsoil, organic material, and soft spots are stripped out, because building a driveway on topsoil guarantees future settling. In Portland's clay-heavy soils, this step often goes a little deeper to remove unstable ground.

2. Sub-Grade Evaluation and Soft-Spot Repair

With the native soil exposed, the crew evaluates and proof-rolls it. Areas that rut or pump water reveal weak soil that should be dug out and replaced with rock. Catching these spots now is cheap; finding them after paving is a tear-out. On wet Multnomah County lots, this is where a careful contractor earns the job.

3. Aggregate Base and Compaction

Crushed aggregate base is spread in lifts and compacted layer by layer. The base — not the asphalt — carries the load, so depth and compaction here determine how long the driveway lasts. Portland's saturated soils generally call for a deeper, well-compacted base than firm, dry ground would.

4. Grading for Drainage

The base is graded to shed water, typically with at least a couple percent of fall. In a city that rains as much as Portland does, drainage is not a detail — water that sits under or beside asphalt is the leading cause of early failure. Good grading at this stage protects the whole investment.

5. Paving the Asphalt

Hot-mix asphalt is delivered, laid, and compacted with a roller while still hot. Residential driveways are commonly paved at 2 to 3 inches of compacted asphalt; heavier-use driveways go thicker and are sometimes placed in two lifts. The rolling must happen before the mix cools, which is why timing and crew coordination matter.

6. Curing

Fresh asphalt needs time to cure and harden before heavy use and before sealcoating. Paving in Portland's warm, dry summer gives the surface a full season to set up before the wet winter returns.

Base Prep for Multnomah County Soil

It is worth emphasizing the base, because it is where Portland installations succeed or fail. The metro's clay and silt soils hold water for months, and saturated soil loses bearing strength. A driveway built on a thin or poorly compacted base over wet clay will crack, sink, and pothole within a few years no matter how good the asphalt on top looks.

A quality Portland install addresses this with adequate base depth, compaction in lifts, geotextile fabric where the soil is soft, and drainage that keeps water moving away. When you compare bids, the base spec is where they differ most — ask every contractor how deep the base is, what aggregate, how many lifts, and whether fabric is included for your soil.

Permits and the Right-of-Way Approach in Portland

The portion of your driveway that connects to the public street — the approach — falls under the City of Portland's right-of-way standards and typically requires a permit. The approach has its own construction requirements distinct from the private driveway surface, including dimensions and how it ties into the curb and sidewalk.

A contractor experienced in Portland handles this part: pulling the approach permit, building to City spec, and coordinating any inspection. Trying to skip or self-manage the approach permit is a common way projects hit problems. This is one of several reasons local experience matters when choosing who installs your driveway.

Timing Your Portland Installation

Portland's reliable paving window runs roughly from late spring through early fall, when the ground has dried and temperatures stay warm enough for proper compaction and curing. Paving in the wet, cold months risks a surface that never sets up correctly. Because the window is narrow and summer fills up, booking ahead is wise — scheduling in late winter or spring for a summer install gets better availability and lets the contractor pick a good weather stretch.

What It Costs and What Comes Next

Installation cost depends on size, base needs for your soil, slope, drainage, and the approach work — Portland's conditions often push real costs above generic averages. For local pricing, see our asphalt driveway cost in Portland guide. If you are weighing a new install against repairing or replacing an existing surface, our driveway replacement in Portland guide covers that decision.

A well-installed driveway lasts decades with simple maintenance. The investment is in getting the base, drainage, and approach right the first time. We are glad to evaluate your site and provide a free, itemized quote for a new Portland driveway.