Flagstone Patio and Backyard Hardscape in La Jolla, 92037

Flagstone Patio and Backyard Hardscape in La Jolla, 92037

This finished project was a $40k-$50k build.

Project Snapshot

Location La Jolla (92037)
Style Modern
Timeline About 29 weeks
Price Range $40k-$50k

– Flagstone: ~950 sf irregular natural stone, set on compacted aggregate base
– Belgard 60mm Mega Arbel pavers: 950 sf (sheet lists both flagstone and Mega Arbel at 950 sf; see manualReviewFields)
– NextGel Polymeric Sand 50lb Bag, Tan: applied to flagstone joints
– Segmental concrete block retaining wall: curved sections with PVC weep lines
– Sod: natural grass, installed in defined lawn area
– Pergola footings: four poured concrete footings
– Boulders: placed as accent and grade transition elements
– Base prep: compacted crushed aggregate per ICPI Tech Spec 2 standards (98% Standard Proctor, ASTM D 698) for pedestrian hardscape

– Site re-graded to meet CRC R401.3 (6-inch fall within first 10 feet from foundation) – French drain system with multiple PVC collection points across the patio field – Downspouts connected to new drain network – PVC drain lines run behind retaining wall with weep outlets – Additional drains added to flagstone patio inlay after client walk identified low points – Final drain pipe capped at project close-out

– Gas line installation required a Simple MEP Permit per San Diego requirements (CPC Chapter 12). Trench was sleeved and work was coordinated with inspection before backfill.
– Retaining wall scope involved curved segmental block sections. Permit threshold in San Diego is 3 feet from top of footing to top of wall per IB-220. Permit status for wall height should be confirmed in project file.

– Total duration: approximately 28 weeks from site setup to final sign-off – Week 1: weather delay, demo rescheduled approximately one week after initial start – Weeks 1-4: demolition, grading, trenching, retaining wall – Weeks 5-12: flagstone installation, pergola footings, gas line – Mid-project pause: client confirmed readiness to resume before a previously anticipated restart – Weeks 13-24: flagstone rework, additional drain installation, sod – Weeks 25-28: final checks items, sod replacement, final sign-off

Project Story

Overview

The homeowner's backyard had an aging deck, poor drainage, and no usable outdoor living space. Install It Direct removed the old structure, installed 950 square feet of flagstone hardscape, built a retaining wall, ran a gas line for a fire pit, added French drains, and laid new sod. The backyard now has a patio, a walkway, and a lawn area ready for daily use.

The Challenge

  • Grade directed runoff toward the house, so water collected in the backyard after rain, addressed in this scope with a French drain on PVC lines tied to the existing system.
  • The existing deck took up most of the backyard but was past its useful life, blocking the 950 sf flagstone patio and pergola footprint while it sat in place.
  • Large sections of bare dirt, no irrigation, no lawn, turned to mud after rain and dust in dry weather before sod and irrigation updates went in.

What Changed

The backyard went from a worn deck and bare dirt to 950 square feet of irregular flagstone hardscape with a connected walkway, a segmental retaining wall, a French drain system with multiple collection points, and a new sod lawn. Gas line infrastructure and pergola footings are in place, so the fire pit and shade structure can be added without additional ground work.

How INSTALL-IT-DIRECT Helped

The homeowner had a backyard that looked finished on paper but wasn't working: an old deck dominated the space, water went the wrong direction, and there was no real place to sit, gather, or let the yard breathe. Install It Direct demolished the deck, re-graded the site, and installed 950 square feet of irregular flagstone across a patio and connecting walkway, along with a segmental retaining wall, French drain system, and a gas line trench for a future fire pit. Sod was laid to complete the lawn area, and pergola footings were poured for the shade structure the homeowner planned to add. Today the backyard has distinct zones: a stone patio for dining, a lawn area for everyday use, and the gas and structural groundwork already in place for a fire feature.

Over 1,000 five-star reviews and 1,500+ San Diego homeowners served.

Design & Build

The Plan

  • Flagstone layout planned as irregular natural stone patio adjacent to the house, with a connecting walkway running along the retaining wall

  • Segmental retaining wall designed with curved sections and integrated PVC weep and drain lines to manage soil and surface water

  • French drain system routed from multiple collection points across the patio and yard, with downspout connections tied into the new drain network

  • Gas line trench trenched and sleeved per CPC Chapter 12, positioned for a fire pit at a designated gathering area

  • Pergola footings poured at four corners to support the shade structure, with grade tolerance verified before concrete placement

  • Sod area defined by flagstone edging on one side and planting beds on the perimeter, with drip irrigation lines reconnected after trenching

See the 2D plan drawing
Project plan

The Build

Demolition and Site Clearing

Crew removed the existing deck, broke out the old paver and tile areas adjacent to the house, and stripped vegetation. Debris was hauled off-site. A weather delay pushed the start back approximately one week before demo resumed.

Grading and Utility Trenching

The subgrade was re-graded to slope surface water away from the foundation. Trenches were cut for the French drain PVC runs, downspout tie-ins, and the gas line sleeve. A lateral valve leak discovered during this phase was repaired before backfill.

Retaining Wall Installation

The segmental concrete block retaining wall was built along the yard perimeter in curved sections. PVC drain and weep lines were set behind the wall face before backfill, and each course was leveled and compacted as work progressed.

Flagstone Patio and Walkway

Large irregular flagstone pieces were set on a compacted aggregate base across the patio and walkway footprint. Joints were filled with NextGel polymeric sand. An initial application had mixed incorrectly with DG material and required full rework by a specialty subcontractor. Additional drains were cut into the flagstone field at low points identified during a client walk, and stones around those drains were re-sloped accordingly.

Pergola Footings and Gas Line

Four pergola footings were poured. The gas line trench was completed and sleeved, connecting the fire pit location to the meter. The final drain pipe cap was installed to close out the drainage scope.

Sod, Irrigation, and final checks

Sod was installed in the lawn area and the homeowner was given watering instructions. Irrigation and drip lines were adjusted to account for the new hardscape footprint. A formal client punch list was addressed, including replacement of a dead sod section and confirmation of valve box cover installation, before final sign-off.

Investment

What would a similar project cost in La Jolla?

Toggle components on/off to estimate your project

Flagstone Patio and Walkway (~950 sf installed) $28,500 – $34,500
Retaining Wall $5,000 – $6,000
Drainage System $4,000 – $4,500
Gas Line, Pergola Footings, and Site Work $4,000 – $4,500
Sod, Irrigation, and Boulders $2,000 – $2,500
Estimated Total

Frequently Asked Questions

How much does a flagstone patio installation cost in La Jolla?

This La Jolla project with approximately 950 square feet of flagstone, a retaining wall, French drains, gas line, pergola footings, and sod came in at roughly $45,000. Flagstone-only projects with simpler drainage run lower, while sites with significant grading or utility work add cost. Most comparable La Jolla backyard hardscape projects fall between $40,000 and $55,000.

Do I need a permit for a flagstone patio and retaining wall in San Diego?

A patio itself does not require a permit in most San Diego cases. Retaining walls do require a permit once wall height exceeds 3 feet from top of footing to top of wall per San Diego. Gas line work always requires a Simple MEP Permit and inspection. On this project, both the retaining wall and the gas line were part of the scope, so permits applied.

How is drainage handled under a flagstone patio?

On this project, PVC drain lines were run beneath the flagstone field with surface collection points at identified low spots. The subgrade was re-graded before base prep to direct water away from the foundation at a minimum 6-inch drop over 10 feet, as required by. Downspouts were also tied into the new drain network. When flagstone is set on a proper sloped base with integrated drains, standing water on the patio surface is not a problem.

Does flagstone require much maintenance after installation?

Flagstone set on a compacted base with polymeric sand joints is low maintenance. The joints should be inspected after heavy rain and re-sanded if erosion occurs. Sealing is optional but extends the life of the joint material. Avoid using deicers in winter, which can damage the stone surface over time.

Can a gas line be added to an existing backyard for a fire pit in La Jolla?

Yes. On this project, a gas line trench was cut across the backyard and sleeved to serve a fire pit location. Per California Plumbing Code Chapter 12, underground gas lines must be buried at least 12 inches deep, and the work requires a licensed contractor, a permit, and a pressure test inspection before backfill. Planning the trench before hardscape is installed avoids cutting through finished stone later.

Your Outdoor Project in 3 Simple Steps

1

Design

We listen to your vision, assess your space, and create a custom design that fits your lifestyle and budget.

2

Build

Our experienced crews bring the design to life with premium materials and expert craftsmanship.

3

Enjoy

Step into your transformed outdoor space and start making memories with family and friends.

Your Project Manager

Patrick Diehl

Patrick Diehl

Born and raised in San Diego, Patrick has managed residential, commercial, and high-rise builds, with a specialty in hardscape. A licensed real-estate agent and certified home inspector, he's committed to delivering every project with quality, compliance, and on-time results.

Ready to Transform Your Outdoor Space?

Let's discuss your project and bring your vision to life.