Cobble, Stone and Soil Delivery in Millbrae, CA

What holds a Millbrae slope or swale together when the winter storms arrive? Coarse stone, sized right and placed deep enough to slow runoff before it cuts. California Rock Supply handles gravel and aggregate delivery in Millbrae, CA, from Class 2 base for drives and pads to rip rap for bank protection. Soils here change fast, with heavy clay in the hills and sandy ground near the shore.

Materials for Millbrae Projects

Erosion work starts with the coarsest stone and works down from there. Order the biggest rock your slope or channel can hold, then step down in size for the layers beneath and around it.

Rip rap, also called rock slope protection, is the heavy end for creek banks, culvert outlets and steep slopes taking storm runoff. Caltrans specifies placed rock on slopes as rock slope protection, and it is the first line of defense when water concentrates.

Large river rock works for dry creek beds and swales where you want runoff slowed and spread rather than piped away. It is rounded, so it shifts and settles instead of locking, which suits decorative and lighter erosion work.

Below that, 3/4 inch drain rock is clean washed stone with no fines, so water moves through it freely. Use it in French drains, drainage trenches and the drainage layer behind a retaining wall.

Class 2 base, also called Class II base rock, is the standard California base material. It goes under driveways, parking pads, pavers and slabs, compacted in lifts to a firm, tight surface. Caltrans specifies it as Class 2 aggregate base.

For the finished surface, Stone Screenings packs firm for paths and patios, and river cobble or Natural Pea Gravel handles decorative beds and borders. Topsoil and shredded mulch finish the planting side of a slope once the stone is set.

Ground and Conditions in Millbrae

Timing decides most of these jobs. The dry season from late spring into fall is the window for base, driveway and paver work, because saturated clay will not compact and stays soft under a plate or roller.

Millbrae sits in the Coast and Coast Ranges ground zone, where soils change over short distances. Sandy ground near the shoreline drains fast, while the heavy clay in the valley and hills cracks when dry and swells when wet.

That clay is why drainage matters more than base depth on many lots. Water that sits on a clay subgrade or runs off a slope will find the weak point, so plan a drainage layer and a place for the water to go before you order stone.

Most rain falls from late fall to spring, often in a few large winter storms and atmospheric rivers. Winter also brings hillside runoff and slides on steep slopes, plus wave and storm erosion along the shoreline bluffs, which is when rip rap and clean drain rock earn their place.

Delivery to Millbrae and the Surrounding Area

Order online and California Rock Supply delivers bulk material by the ton to your site in Millbrae, in San Mateo County. Coverage extends to San Mateo, Daly City, Redwood City, South San Francisco and San Bruno.

Coverage is the first thing to settle. A ton of stone spreads thinner than most people expect, so measure the area and the depth you need, then order the tonnage that fills it. For a base layer, work from a compacted depth of 2 inches or more per lift.

Lead time depends on the material, the volume and the schedule for your area, so build a little slack into a job that has to finish before the rain. Plan where the truck can pull in and dump, and keep that path clear.

Order Stone for Your Millbrae Project

California Rock Supply delivers rip rap, drain rock, Class 2 base, sand and soil across Millbrae and San Mateo County. Measure your area, pick the size that matches the job, and place your order online. We will get the right stone to your site.