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

Types of Patio-Sunroom 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, and similar patio 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 (cylindrical) or square (rectangular).…

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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…

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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…

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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…

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Welded Aluminum and Railings

Regarding any aluminum railing project, it is imperative to understand the life-safety issue that arises when welding an aluminum railing post. A rail is classified as a life-saving fall guard for any elevation above 31 inches. The aluminum alloys normally used (such as 6061-T6) get their strength from a heat-treatment process. Welding weakens the heat-treated aluminum…

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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  

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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…

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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…

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