Parsways Structural Engineering Blog

Adding an upper level to an existing residential property requires a complete re-engineering of the building’s load-bearing system. In high-density urban areas across Ontario, from Toronto to Mississauga, vertical expansion is a popular alternative to moving. However, executing a second storey addition structural design Ontario requires meticulous planning to ensure the home can handle the extra weight. Many general contractors and designers focus heavily on spatial layout, b

Industrial facilities across Ontario frequently undergo operational changes as commercial business demands evolve. Repurposing an existing warehouse space for heavier storage is highly common in major manufacturing and logistics hubs such as Mississauga and Brampton. However, introducing new storage loads without verifying structural capacity poses significant safety risks, especially when the initial design criteria of the building are completely unknown. When modifying exis

Starting construction before structural drawings are finalized may appear efficient when schedules are tight. In Ontario, however, early work can create technical, permit, inspection, and liability issues that are difficult to correct later. Structural drawings define the load path, member sizes, connection requirements, foundation design, lateral stability, and limitations needed for code-compliant work under the Ontario Building Code (OBC). Final Structural Drawings and Per

Remote review is useful for screening, document checks, and coordination. However, some structural reviews cannot be completed remotely because the engineer must verify conditions that are not visible in drawings, photos, or videos. In Ontario projects, including Toronto, Newmarket, Vaughan, Markham, Barrie, Hamilton, and smaller towns, structural review must be based on reliable information. Where information is incomplete, an on-site structural review may be required before

Building permit delays in Ontario usually begin before municipal review starts. A package may look complete, but if the drawings do not clearly show the structural scope, load path, existing conditions, or code basis, the reviewer will issue comments instead of approval. The current Ontario Building Code adopts the National Building Code of Canada 2020 with Ontario amendments. Structural submissions must coordinate with applicable Part 4 or Part 9 requirements and relevant CS

Not every construction or renovation project in Ontario requires a structural engineer. However, when structural elements are modified, loads are changed, or building permit documentation is involved, engineering review is often required to confirm safety and compliance. Understanding when structural engineering is needed can help avoid permit delays, construction issues, and unnecessary rework—especially in active markets such as the GTA, where permit review timelines can al

Existing decks in Ontario may need more than a repair estimate. For condominium and multi-unit properties, the concern is often structural condition, code compliance, missing drawings, and safe future use. A structural review of existing decks is commonly needed when the deck was built years ago, the original drawings are unavailable, or a change is proposed. This includes deck extensions, altered access, or a “door to nowhere” condition. Existing Deck Condition Assessment Ol

In many Ontario construction projects, existing concrete slabs are often assumed to have sufficient strength for new loading conditions. In practice, the structural capacity of existing slabs in Ontario is rarely defined with certainty. Across industrial and commercial buildings in Ontario, including major urban centres such as Toronto and surrounding regions, changes in use, storage demand, or equipment installation frequently introduce loads that were not part of the origin

Garage slabs are often perceived as simple concrete surfaces. In reality, they act as part of a soil-supported structural system that transfers loads, responds to subgrade conditions, and must perform under Ontario’s freeze-thaw environment. From a structural engineering standpoint, even a typical residential garage slab requires careful design to ensure long-term performance and compliance with local building requirements, including the Ontario Building Code (OBC). Structur

In Ontario construction, shear keys are commonly included in wall–footing details for basement walls, retaining walls, and foundation systems subject to lateral loading. The intent is to improve sliding resistance by providing mechanical interlock at the interface. However, in many projects, the use of shear keys is not always explicitly supported by project-specific shear calculations. As a result, the detail is often carried forward as part of standard sections rather than

A Letter of Exemption (LOE) is sometimes requested when warehouse racking systems or mezzanine platforms are installed in industrial and commercial buildings across Ontario. The letter is issued by a professional engineer to confirm whether the proposed installation requires a building permit or structural review under the Ontario Building Code (OBC). In many warehouse projects, storage systems such as pallet racking may appear structural but function as equipment installe

A third-party structural review in Ontario is an independent technical assessment of structural design documents prepared by another engineer. The purpose is to verify compliance with the Ontario Building Code (OBC – current edition) , referenced CSA standards, and accepted engineering practice. This process is commonly required for complex, high-risk, or unconventional structures. Municipal building officials, project owners, insurers, or peer engineers may request it. Regu

In Ontario warehouses, when installing or changing industrial pallet racks, a Pre-Start Health & Safety Review (PSR) may be required. This applies when racks are new or significantly modified and could pose a safety risk if they fail. Typically, this requirement applies when the racking system adds significant weight, requires anchoring, or affects stability. A licensed Professional Engineer (P.Eng.) must complete and sign off on the review when required, providing the P.Eng

In Ontario construction projects, a structural engineer site inspection may be required as part of the permit process. In practice, this is the engineer’s “general review” site visit—an on-site observation to confirm that the work observed is generally consistent with the sealed drawings and the Ontario Building Code (OBC). These inspections are not general quality checks; they are targeted engineering reviews tied to specific structural elements. For contractors, understandi

Mortise and tenon joints are among the earliest forms of timber connections still encountered in contemporary structural engineering practice. Today, the mortise and tenon joint is most commonly reviewed by structural engineers as part of renovation projects, porch framing, or architecturally exposed timber assemblies in Ontario. From an engineering perspective, these joints are evaluated as load-carrying connections with specific behavioural limits, rather than as traditi

Timber grades Canada play a central role in how wood members are selected and evaluated for structural use in Ontario. In structural engineering, timber is not treated as a uniform material; its performance depends on both the species of wood and the grade assigned through standardized timber grading systems. In Ontario renovations and structural alterations, understanding these distinctions is essential for predictable load paths, acceptable deflection behaviour, and complia

Flitch plate beams are composite members that combine timber and steel to increase bending capacity without increasing beam depth. In Ontario renovations and structural alterations, they are often considered where architectural constraints or headroom limits make all-wood beams impractical, while steel-only solutions may be difficult to install or integrate. A flitch plate beam is not simply a stronger piece of wood. Its performance depends on effective composite action betw

In reinforced concrete design, lap splices are not a drafting formality. They are a force-transfer mechanism . A lap splice allows tensile force to pass from one reinforcing bar, through the surrounding concrete, and into the adjacent bar. Its performance depends on bond behaviour , detailing, and how forces are distributed within the section. CSA A23.3 addresses this behaviour by classifying tension lap splices as Class A or Class B . These classes do not describe construct

In structural concrete design, durability is defined , not assumed. CSA A23.1 addresses durability through concrete exposure classes , which link concrete performance requirements to the environmental conditions an element is expected to experience over its service life. Exposure classes are not a measure of concrete “quality” or strength. They reflect an engineering assessment of environmental risk —moisture, freeze–thaw cycling, and potential chloride access. If exposure is

Understanding when to use U-Fill ( Controlled Low-Strength Material / Flowable Fill) versus Lean Concrete helps engineers, contractors, and project managers choose the right material for trench backfilling, sub-bases, bedding, or void filling in Ontario projects. This comparison covers properties, typical uses, performance differences, and practical considerations from a structural engineering perspective. What Is U-Fill (Flowable Fill / CLSM)? U-Fill — also called flow