Plan the Patio Around How You Use It
Start with what goes on the slab. A dining table, a grill, a fire table or a future shade cover all change the size and the layout. Tell the contractor what you want now and what you might add later.
A slab that will hold a patio cover may need footings in set spots. It is cheaper to plan those now than to cut into a new slab.
What the City Says
The Carlsbad homeowner guide says you need a permit for patio covers, decks and enclosures. It does not say anything about a flat patio slab on its own. Ask the city about your slab before work starts, and plan on a permit for any cover you build over it.
The city takes permit applications through its online Customer Self Service portal. A licensed contractor files these all the time and can tell you what to expect.
Drainage and Soil
A patio should slope a little so rain runs away from your walls. Ask where the water goes and how the edge meets your lawn or planters.
Much of the coastal plain in the county has clay that swells when wet. Ask about base depth and joint spacing so the slab can move without cracking in random lines.
Finish Options
A smooth trowel finish, a light broom finish, exposed stone and stamped patterns all work on a patio. Ask how slick each one gets when wet, since pool decks and shady spots need more grip. Our stamped concrete page covers patterns and sealers in more depth.