Larkspur Hot Tub Pads

A filled spa with four people in it is a small car parked in one spot forever. That load never moves, never spreads, never gets a break. Which is why a hot tub pad is one of the few residential slabs where we go heavier than the usual rules and don't negotiate about it. Six inches. Steel on a tight grid. Base compacted in lifts, not dumped and raked.

Here's how the day itself runs, because almost nobody has watched a pad get poured, and the sequence explains the price better than any sales pitch could. Out here it's a logistics problem too. The mix has to reach a spot that's usually behind the house, down a slope, and a long way from anywhere a loaded ready-mix truck can safely stand.

Everything that happens before a truck is even ordered

• Tub model and filled weight confirmed, along with the manufacturer's footprint and access-panel side
• Placement walked with you in person: sightlines, wind, snow shed off the roof, and the run back to the door
• Truck route and pour method settled, whether that's a chute, a buggy, or a pump line down the slope
• Excavation to depth, then road base placed in lifts and compacted, each lift on its own
• Perimeter thickened and forms set dead level, checked with a laser rather than a string
• Electrical conduit sleeved and stubbed exactly where your electrician wants it, before any steel goes down
• Number 4 rebar tied on a tight grid and lifted onto chairs so it lands mid-slab, not on the dirt
• Any drain line, sleeve for a future gas run, or step footing set and braced

Why the conduit decision comes first

Every hot tub needs power brought to a disconnect, and the cleanest way to do that is under the slab in a sleeve rather than around it later. We want your electrician's input before we tie a single bar, because the stub location has to clear the tub's equipment bay and land where the disconnect can legally sit. Once concrete is down, moving that conduit means cutting the pad you just paid for. The electrical work, the permit for it, and the inspection are their scope; getting the sleeve in the right place is ours.

The same logic covers anything else that wants to live under the concrete. A sleeve for a future gas line to a fire feature. A drain if the pad sits in a spot that collects roof runoff. On sloped Larkspur lots we'll sometimes run a small drainage layer and an outlet under the pad, because a spa surround that traps hillside water becomes an ice rink by December. It costs almost nothing on pour day and it's a project later.

Pour day, hour by hour

Cold, wind, and the Larkspur calendar for a spa pad

May into October is the comfortable window, and September might be the best of it: warm afternoons, cool nights, dry air, and runway for a full cure ahead of hard frost. Summer pours start early, because the afternoon buildup over the foothills is dependable enough to schedule around. Storm water hitting a slab mid-finish gets worked into the top layer, and you pay for that later in dusting and scaling.

Winter pads do happen. Heated mix water, a non-chloride accelerator, blankets over the fresh work, and a close read of the fronts. Frozen subgrade is the hard no: concrete set over frost drops when that frost releases. On a shaded north-side yard at 6,720 feet the ground stays hard long after the air feels fine, so we probe instead of guessing.

One altitude wrinkle worth planning for. Wind and thin-air sun pull moisture out of fresh concrete quickly, so we keep the pad covered and wet-cured on breezy days. Surfaces that dry too fast craze, and nobody wants to look at that under a brand new spa.