Alex Rivera, PE

Alex Rivera spent the first decade of his engineering career in the structural engineering group at Thornton Tomasetti, a global engineering firm known for complex structural projects. Working from their Los Angeles office, he served as Engineer of Record on 250+ residential foundation designs across Southern California, ranging from standard spread footings to deep caisson systems on hillside sites with expansive soils. He coordinated with geotechnical reports and translated soil bearing capacity data directly into concrete dimensions and rebar schedules — the same calculation sequence now automated in CalcSummit's foundation and concrete slab tools.

After leaving Thornton Tomasetti, Alex moved into independent structural consulting, working directly with general contractors to resolve field-level structural questions. He encountered a repeating problem: residential contractors and owner-builders were using generic online calculators with no code basis — some computing rebar spacing without accounting for concrete cover, others ignoring ACI 318-19's minimum reinforcement ratios for slabs on grade. He began writing formula-verified calculator tools to correct these errors. Those tools became the structural core of CalcSummit.

At CalcSummit, Alex writes and personally reviews every calculator in the structural, concrete, rebar, deck, framing, and foundation categories. His review process starts with the applicable standard — ACI 318-19 for reinforced concrete, IRC 2021 Section R403 for footings and foundations, NDS 2018 for timber framing connections — and verifies that the calculator's formula, result output, and waste-factor assumptions match current code requirements. When a code edition updates, Alex re-verifies affected calculators within 30 days of the effective date.

Alex also holds ICC Certified Building Inspector credentials alongside his PE licenses. He is an active member of the American Society of Civil Engineers (ASCE) and has presented at regional ASCE chapter meetings on practical structural calculation methods for residential construction. His published work includes three construction-engineering articles in Construction Specifier and a peer-reviewed feature on residential structural loads in ENR.com.

He holds PE licenses in California (License #C-89412, issued by the California Board for Professional Engineers and Land Surveyors) and Texas (License #P.E.-98765, issued by the Texas Board of Professional Engineers and Land Surveyors). Both licenses are publicly verifiable through the respective state licensing board registries.