Paver Patios in Seattle

Deeper than the four inches often quoted. On our glacial till the subgrade does not drain, so the base has to handle the drainage and the load spreading at once. For a pedestrian patio we are typically excavating six to eight inches below the finished surface for the base build-up, plus the bedding layer and the paver itself. It goes deeper where the ground is soft, where a vehicle will cross it, or where the lot sits at the bottom of a slope taking water from uphill — and in those cases it usually gains a geotextile separation layer as well.

Almost always an inadequate base rather than a problem with the surface itself. If the base was too shallow, was not compacted in layers, or was laid straight onto undisturbed clay-heavy till with no drainage, water gets underneath, the fines wash out and voids form. The patio then moves under load, which is the classic rocking slab. Re-laying the surface without addressing the base buys a year or two. The real fix is lifting the units, rebuilding the base properly with a free-draining compacted build-up, and re-laying — and on a decent original the pavers themselves are usually fine and get reused.

Pavers are the default recommendation here and it is not a close call. They tolerate the small ground movement that our wet winters and till subsoil produce, and if a section settles or a unit is damaged you lift and reset that part rather than breaking out a slab. Poured concrete looks cleaner and costs a little less to install, but it will crack eventually and repairs are visible forever. Flagstone is the most characterful and the most expensive, because every stone is cut and fitted by hand. If you want something unlike your neighbour's garden and have the budget, flagstone; otherwise pavers.

More than on an open lot, and the honest answer is that it is mostly about material movement rather than noise. Base rock, sand and pavers arrive by the pallet and have to be cleared from the kerb the same day on streets with no off-street parking, then moved to the back garden by hand or barrow. We time deliveries to what can be cleared in a day, arrange any street occupation permission needed, and sequence the work so the frontage is not obstructed longer than necessary. Expect the side return to be a working route for the duration.