Signature Stone

A material the code does not name needs evidence of adequacy from ISO/IEC 17025 laboratories (Los Angeles Municipal Code 98.0501).

A retaining wall is built without a permit only to the LADBS Figure 1 detail: reinforced block, a 12 in footing embed, 2,500 psi concrete, grouted cells and at most 30 in exposed where a walkway sits behind, on a slope no steeper than 1:5 (LADBS bulletin P/BC 2026-002).

Walls of rubble or stacked block, including pre-manufactured stacked block, need a current LADBS Research Report or an approved-agency Evaluation Report (LADBS bulletin P/BC 2026-002).

Plans and calculations released for construction are signed, sealed and dated by a California engineer or architect (LADBS bulletin P/BC 2026-073).

A 2023 laboratory study found that hot-mixed quicklime clasts in a Portland mortar closed a 0.5 mm gap over weeks under water flow. It is a laboratory result and no product follows from it (Seymour and others, Science Advances, 2023).

Inca masons shaped each stone to meet its neighbors. Signature Stone starts from the same habit: every stone is chosen and cut for its place on a numbered plan, and the plan is drawn before the first cut.

Roman builders made mortar, plaster and wash from burned and slaked limestone. The lime finishes on the steps and low walls carry that mineral character, where the engineer and the plan check accept them.

The 2023 study of hot-mixed lime in mortar took its question from Roman concrete. It remains a laboratory result, and Signature Stone makes no claim from it.

A stone selection, with samples brought to the site.

A numbered layout drawing: every stone placed, every joint planned.

Cut stone paths, patios and steps on a prepared, drained base.

Low walls faced in stone, built to the LADBS Figure 1 detail or to an engineer's design.

Lime-based setting and finish coats where the engineer and the plan check accept them.

Sealed plans where LADBS requires them (LADBS bulletin P/BC 2026-073).

A written list of every material used.

No earthquake claim. We do not call any wall, step or stone work safe against earthquakes.

No repair claim. We do not say mortar or stone repairs its own cracks. The 2023 lime study is a laboratory result (Seymour and others, Science Advances, 2023).

No living-stone claim. A field study of bioreceptive concretes found that Portland cement out-colonized a phosphate cement and showed no visible moss (Manso and others, 2015 field study). We promise no moss and no living growth on stone.

No fire rating. We rate no stone, mortar or finish for fire.

No stacked block without a report. We build no wall of rubble or stacked block without a current LADBS Research Report or an approved-agency Evaluation Report (LADBS bulletin P/BC 2026-002).

No unnamed materials. We use a material the code does not name only with laboratory evidence of adequacy (Los Angeles Municipal Code 98.0501).