Concrete Shear Transfer Across a Joint

Uncategorized
When a composite concrete member is stressed in flexure, it needs to transfer shear flow across any longitudinal joints in the member. Take, for example, the classic residential footing: a tall stem wall with an enlarged T footing at the base. The two sections may be poured at different times,…

Concrete Wall Strengthening

Uncategorized
Often, we need to strengthen an existing concrete wall to support new construction. This can occur, for example, when repairing an under-sized retaining wall in place. There are two general approaches to this problem: the simpler and more conservative is to design the new concrete layer to resist all forces.…

Multiple Buildings on One Lot

Building Code
This article discusses the code implications of having multiple standalone buildings on one lot. Specifically, we will investigate fire separation requirements and code-compliant options to reduce these requirements. Fire Separation The basic fire separation requirements for a building are based on the fire separation distance for each exterior wall. Here…

Retaining Walls – Resisting Sliding

Geotechnical Engineering, Structural Engineering
This article discusses the techniques and tricks available to resist sliding when designing a retaining wall. Concrete retaining walls, ecology blocks, rockeries, and other common retaining wall designs need to resist the driving pressure of earth forces without tipping over and without sliding along their base. It has been our…

Energy Code Requirements for Significant Alterations and Conversions

Energy Code
This article discusses energy code requirements for residential buildings that are undergoing a significant alteration or change of use, with no addition of floor area, while still staying within the Residential provisions of the energy code. This article specifically deals with the Washington State Energy Code (WSEC). The example that…

Structural Requirements for Existing Buildings

Building Code, Structural Engineering
This article discusses the structural requirements for projects involving existing buildings. It covers repairs to damaged buildings, alterations of existing buildings, additions, and changes of use. This article focuses on residential buildings (R-2 and R-3 occupancies). Applicable Codes Buildings that fit within the scope of the IRC (one- and two-family…

Fire Sprinkler Requirements for Residential Change of Use

Building Code
This article investigates the requirements for fire sprinklers when an existing R-3 occupancy (single-family residence / duplex / townhouse) is converted to an R-2 occupancy (apartment / 4-plex). For new construction, R-2 occupancies are regulated under the IBC rather than the IRC. Per IBC, all residential structures require fire sprinklers.…

Type B Accessible Units

Accessibility
This article outlines the requirements for Type B accessible units. Multifamily residential buildings with 4 or more units require at least some of the units to be “Type B” accessible. These are not fully accessible units, but they include features that make them more easily adaptable for an occupant who…