Gravel, Rock & Site Preparation in Seattle

Because the ground underneath will not help. In a well-drained sandy subsoil, a modest base works partly because water passing through the surface keeps going down and away. On glacial till it does not — it reaches the hardpan and stops, then moves sideways through whatever base was laid. That means the base is doing two jobs here: spreading load and providing the drainage path the subgrade cannot. Undersize it and water sits in it, fines migrate, voids form and the surface above starts to move. This is the single most common reason we are called to rebuild someone else's patio.

It means placing base material in shallow layers, usually a few inches at a time, and compacting each layer before adding the next. It matters because a compactor only transmits meaningful force a limited depth into loose material — run one over twelve inches of freshly tipped rock and you get a firm crust with uncompacted material underneath it. That looks identical on the day and settles over the following two years. Lifts are slower and use more machine time, and they are the reason two quotes for the same patio can differ substantially while describing the same finished surface.

Yes, and a large share of our Seattle work is exactly that. The methods are hand excavation, barrowing through the house with floor protection, conveyor, or in a few cases craning material over the roof. What changes is not whether it can be done but what it costs and how long it takes — a job that is two days with an excavator on the drive can be four or five by hand. We walk the access route before quoting and price it explicitly, which sometimes makes our figure look higher than a quote from someone who has not yet worked out how the material is getting in.

It leaves in our trucks and goes to appropriate disposal or recycling depending on what it is. Clean excavated soil and clean broken concrete have different routes, and material with contamination or debris in it has another again. It is worth knowing that spoil volume is always greater than the hole it came out of — excavated ground bulks up considerably once it is loose — which is why disposal is routinely underestimated. Where the site can genuinely use it, regrading spoil on your own lot is cheaper than hauling it, and we will suggest that when it is a real option rather than a way of leaving a problem behind.