Proposed Deck Renovation

Project Details

This project involves the structural analysis and engineering for the renovation and reconstruction of an existing exterior residential deck and site access stairs. The comprehensive scope required modern engineering solutions for the entire rebuilt structural assembly, including joists, beams, posts, and ledgers, all supported by a specifically designed foundation system including landings and site stairs. The primary structure utilizes Douglas Fir-Larch (DF-L) sawn lumber of various sizes (e.g., 2×6, 4×8, 8×8) integrated with specialized structural connectors and hold-downs to ensure a safe and durable assembly. The design process included a rigorous structural analysis to ensure the deck could safely withstand gravity and environmental loads in accordance with the 2022 California Building Code (CBC), IBC 2021, and ASCE 7-22 provisions. The structural elements were engineered to support a deck live load of 60 psf and a ground snow load of 4 psf. Special attention was given to lateral load resistance through the use of wood shear walls and timber moment frames utilizing knee bracing to provide stability against wind speeds of 92–93 MPH (Exposure B) and high seismic requirements for Seismic Design Category E. The foundation system features independent reinforced concrete pad footings (CF1, CF2), wall footings (WF1), and retaining walls (RW1) designed to perform reliably under an allowable net soil bearing pressure of 2,000 psf. Structural integrity is secured through Simpson Strong-Tie components, including CCQ column caps, CPTZ post bases, and DTT hold-down connectors.

Role

Structural Engineer/Designer

Services Provided

The scope of structural engineering services included the preparation of complete structural calculations and structural drawings for the reconstruction of the exterior deck and the construction of the associated site access stairs. Structural calculations included loading analyses for wind, seismic, dead, and live loads in accordance with the governing provisions of the 2022 California Building Code (CBC) and ASCE 7-16. The work included the structural analysis and design of the rebuilt exterior deck system, covering deck joists, beams, posts, ledgers, and all required connectors and fasteners to ensure adequate load transfer and a continuous structural load path. The analysis verified member capacities, connection forces, and support reactions under applicable gravity and lateral loads. In addition, the scope included the structural analysis and design of the site access stair system, including stair stringers, intermediate landings, support framing, connections, and required foundations or footings to safely support imposed loads and ensure code compliance.
Structural drawings were prepared to clearly illustrate the structural design and support construction and permitting requirements. The drawing set included a Deck Framing Plan identifying the layout, sizing, and spacing of joists, beams, posts, and ledger attachments; a Stair Framing Plan showing the configuration of stair stringers, landings, and structural supports; and Structural Building Sections illustrating load transfer and cross-sections of the terrace/deck assembly to clarify vertical relationships and load transfer. The drawings also included typical structural details for deck framing, stair framing, connection requirements, and foundation supports, along with general structural notes and technical specifications necessary for proper construction and coordination with project design documents. All deliverables were prepared to provide clear guidance for permitting review and field construction while ensuring compliance with applicable building codes and structural design standards.