A pool deck on a hillside pad is the last flat surface before the ground drops away, and that is the job it has to do. Most Mission Viejo pools were dug at the back of the pad in the 1970s and 1980s, with the deck running from the coping to within a few strides of the top of the rear slope. Every gallon that lands on it, splash, backwash, a winter storm, goes wherever the surface sends it, and a surface that sends it over the crest puts it into fill that was never graded to take it.
Trevor Lindqvist founded Saddleback Mission Viejo Concrete in 2018 after 17 years on crews across south Orange County, and a pool deck on a graded pad is the job he has stood over most. The first decks here were thin, a spray-textured topping over 3 inches of concrete laid on the pool's own backfill, poured flat because nobody had asked where the yard drain was. He shoots the fall from the coping to the drains first, because the fall is what the new deck is for.
Decks are built under a CSLB C-8 license with liability insurance on every job, to the California Residential Code and to the bonding the California Electrical Code asks for within 3 feet of the water, which the City of Mission Viejo's Building Division inspects before it is covered. The finished deck carries a written workmanship guarantee against defects in how it was built, and the terms are printed on the estimate you sign.