General opinions and theories of the methods which govern our engineering industries

ASCE Risk Categories Explained

Background Building codes require that buildings be classified by their level of importance in determining the risk taken with safety factors against their failure under critical design loads. Calculations for the structure’s overall stability, flexure, and fatigue are all based on the assumption of a given risk category design level.  ASCE 7 references risk category…

Flood Engineering Glossary

FLOOD GLOSSARY The following is provided as a curated summary of terms taken from the referenced standards that appear in the article footing. NATIONAL FLOOD INSURANCE PROGRAM (NFIP) The Federal program, create by an act of Congress in 1968, that makes flood insurance available in communities that enact satisfactory floodplain management regulations.   FLOOD INSURANCE…

Flood Resistant Design & Floodproofing of Buildings

An engineer’s walk through of the design requirements for flood resistant design of building components With Engineering Express’s early start with floodproofing designs for floor barriers and exterior glazing in projects across the US, we quickly became experts in this field.  We’ve witnessed and directed static and dynamic flood testing, sat on industry meetings, met…

Types of At-Grade Footings Explained

Here’s a description and illustrations we’ve created for footing types we frequently reference in our work for sunrooms, pergolas, carports, screen rooms, signs, and similar at-grade building component structures.   An isolated footing is used to support a single post. Isolated footings are independent footings which are provided for each support. they can be round…

Wind Speed vs. Wind Pressure Explained

Many who don’t understand how wind works will state a product is rated to a specific wind velocity which is false advertising and not true. “Rated to 180 MPH wind” is frequently seen in marketing materials which is a false and misleading statement that comes with many unwritten disclaimers.   The formula that converts wind velocity to…

ASCE 7 Main Wind Force vs. Components & Cladding Explained (MWFRS vs. C&C)

ASCE 7 separates wind loading into three types: Main Wind Force Resisting System (MWFRS), Components and Cladding (C&C), and Other Structures and Building Appurtenances. MWFRS is defined as “(a)n assemblage of structural elements to provide support and stability for the overall structure.” Typically, members which receive loading from two surfaces are designed to resist MWFRS…

Phantom Screens: Is a Florida Product Approval Required?

Product Approvals for building components are the general rule in Florida.  Building officials, architects, insurance companies, even homeowners ask for them all the time, frequently refusing permits, insurance discounts, and product installations. So what is the legal ruling on when and if product approvals are required for this product? The Florida Building Code requires only…

When is a Fence or Railing 75% Open?

The Scenario The question comes up from time to time regarding requirements for a fence or railing to be 75% open (such as in the Lighthouse Point FL Building Code Amendments).  This is the case for example in Florida when overlooking the Intracoastal in Broward County.  This porosity also affects the design calculations for the…

Steel Bolt Edge Distance Requirements

Per AISC-ANSI-360-10, the minimum edge distance for bolts is to follow the below table J3.4     https://www.scribd.com/doc/115942657/Minimum-Edge-Distance-Table-AISC-ANSI-360-10-Specifications-for-Structural-Steel-Buildings   or buy direct from AISC: https://www.aisc.org/store/p-1578-steel-construction-manual-14th-ed-fourth-printing-hardbound.aspx  

Metal Fasteners UNC vs Spaced Thread

Metal fastening is designed per the requirements of the American Institute of Steel Construction (AISC): Specification for Structural Steel Buildings in conjunction with the American Architectural Manufacturers Association (AAMA): TIR-A9-14 Design Guide for Metal Cladding Fasteners.   The (2) most common types of fastener threads used in construction are Unified Coarse Thread (UNC) more commonly…

The Recently Updated Saffir-Simpson Scale

First, it needs to be said that there is a complicated formula that converts wind velocity to wind pressure.  Many wind pressure values can exist from a single wind velocity which vary based on roof height, topography, terrain, even code version, and more.  See our wind speed to wind pressure calculators for different ASCE codes by…