Paver Installation in Bothell

By testing rather than looking, because the surface tells you very little. The usual field checks are simple: dig a test hole and see what comes out, push a probe in and see how far it goes with hand pressure, and watch whether the hole holds water. Ground that a probe sinks into easily, or that produces a hole with water standing in it a few hours later, is telling you the base needs help. What we would not rely on is how the lawn feels underfoot in summer — alluvial ground drains and firms in a dry spell and softens again as soon as the water table rises, and the paving has to be built for the second condition.

It keeps two materials from becoming one. Clean base rock sitting directly on soft ground does not stay clean: under load, the stones press down into the subgrade and the fine soil works its way up into the voids between them, and over a few years you have a mixed layer that neither drains nor carries load. A separation fabric between them stops that exchange while still letting water pass. It costs very little relative to the job and it is the difference between a base that is still doing its job in fifteen years and one that has quietly turned into muddy gravel.

Not automatically, and occasionally that makes things worse. On soft alluvial ground, digging further can simply take you into wetter, weaker material and produce a hole that fills with water — at which point you have a deeper problem rather than a solved one. The more reliable approach is to separate and spread: geotextile between subgrade and base, a base wide enough to distribute the load beyond the edge of the surface, and where necessary a stabilising layer rather than more of the same rock. The right depth is a judgement made after seeing what is actually down there, not a number chosen in advance.

Yes, but the trench needs treating as its own condition rather than as part of the general ground. Backfilled trenches consolidate for years after the work, and they do it independently of the undisturbed ground on either side — which is why paving laid across one so often develops a dip that follows the trench line exactly. Where we know a trench runs under a proposed surface, the base gets extra depth and reinforcement across that band, and where the backfill is recent, the honest advice is sometimes to wait a season. Being told where your utilities were dug in is worth doing before design, not during excavation.