Bulk Aggregates for Patios in Coulee City, WA

Washington Rock Supply handles gravel and aggregate delivery in Coulee City, WA, from 5/8 minus for a packed base to the sand and chips that bed a patio. This is Columbia Basin ground, and what you put under flatwork decides how it holds up.

Ground and Conditions in Coulee City

Across the Columbia Basin, Yakima Valley and the channeled scablands, windblown loess sits over Columbia River basalt. Where the Ice Age floods ran, the loess was stripped away and the basalt left bare, with sand and gravel bars dropped in the coulees.

That gives you two very different sites. On deep silt, the ground sheds water instead of soaking it up.

Where flood gravel is at the surface, water disappears straight down.

A thin base over silt is where patios and pavers fail here. The fines in the soil hold moisture, the subgrade softens, and the surface rocks and settles out of line.

The fix is a compacted granular course deep enough to bridge that soft layer.

Wind off bare, dry silt moves soil, and a cloudburst or a fast thaw cuts rills and gullies into uncovered loess. Irrigation runoff moves soil too, so cover ground early.

Work around winter. The wet weather season for erosion control runs October 1 through June 30, and once the ground freezes, placing and compacting base material stops being practical.

Frost heave in an unbound base is something to design for. Frost depth in Grant County is 18 inches, though the county or city building department sets the figure, and it runs deeper with elevation.

Materials for Coulee City Projects

Start with bedding, because that is what a paver or flagstone surface actually sits on. Crusher dust, also called 3/8 minus or screenings, is the fine end of the minus range.

It compacts rather than drains, which is exactly what you want under a setting bed.

Stone Screenings beds pavers and flagstone and fills joints once the surface is set. For a permeable system, use 3/8" Crushed Stone instead, a washed stone with the fines taken out so water passes through the joints.

Under the bedding goes the structural course. 1 1/4 Minus, or crushed surfacing base course, has a larger top size and fewer fines than 5/8 minus, so it carries load and stays workable on soft wet ground.

Finish with 5/8 Minus, the crushed surfacing top course Washington yards call for. The fines are left in, so it packs hard and sheds water rather than soaking it up.

Sharpen the grade with Walkway Gravel, or 1/4 minus, which packs down tight underfoot on paths and side yards.

Delivery to Coulee City and the Surrounding Area

You order online, choose a quantity by the ton or by the yard, and pick a delivery date at checkout. A dump truck then tips the load on site.

Choosing between tons and yards comes down to how you measured the job. Each product page has a calculator, so you can size the load before you place the order.

Washington Rock Supply delivers across Grant County, including Moses Lake, Ephrata, Quincy, Mattawa and Warden as well as Coulee City.

Questions About Ordering

What gravel is best for a driveway in Coulee City?

For most drives here, start with 1 1/4 minus as the structural course and top it with 5/8 minus. The 1 1/4 minus carries load on soft ground, and the 5/8 minus packs hard because the fines are left in.

For a long rural approach, Driveway Gravel is sold as a blend alongside those graded courses.

How much material will my project need?

Quantities are ordered by the ton or by the yard, so you need the area and the depth you plan to build to. Each product page has a calculator, and that is the place to size the load.

Have your measurements ready before you start the order online.

Order Your Patio Base in Coulee City

Sort the bedding and base courses first, then size the load with the calculator on the product page. From there, order Washington Rock Supply material online by the ton or yard and pick your delivery date at checkout.

A truck brings the bulk aggregate to your Coulee City site.