HMMA Q1 2021 Newsletter

April 5, 2021

Continuously Welded Frames

There are always multiple ways to say something and communicate 90% non-verbally. When it comes to the construction of hollow metal, the words used to specify the type of frame weld is very important, but the challenge is different areas in North America sometimes use different words. HMMA has created a quick-read TechNote to help Architects gain a clearer understanding of the frame weld types and the definition of the terms. Continue reading below for the Key Frame Component definitions and then click the link to be taken directly to the quick read HMMA TechNote to see visuals of the Continuous weld setups based on the type of frame joint.

  1. FRAME MEMBER – A part of a frame such as a head, jamb, mullion or sill, also called frame profile, see Figure #1 in HMMA Tech Note TN02-03.
  2. FRAME ELEMENTS – Specific parts of a frame member such as soffit, stop, rabbet, face and return. See Figure #2. A double rabbeted frame is shown for illustration purposes only; alternate designs use the same nomenclature. Figure #2.
  3. PERIMETER JOINT – The intersection of two or more frame members or elements that are accessible through the throat or from the unexposed side of the frame member. As perimeter applies, this is the outside boundary of the frame. Perimeter joints of a continuously welded frame shall have all elements of the frame member continuously welded; soffits, stops, rabbets, faces and returns. Faces and returns may be welded either internally or externally. Soffits, stops, and rabbets shall be welded internally. Figures #3A – #3D illustrates typical perimeter joints; Figure #3A illustrates a saw and punched mitered corner joint.
Click here to view weld types and joints in the HMMA Tech Note on Continuously Welded constructions.

Hollow Metal Selection Based on the Type of Application an Architect Has to Match

by Matt Lee

Hollow metal is found quite frequently in most areas of any building. But the type of hollow metal that should be used in any specific situation can vary greatly based on a variety of factors.

In case you’re in charge of choosing hollow metal applications for any type of building, let’s take a look at a few things you need to consider before moving forward.

Hollow Metal Application Considerations
In contrast to wood framing, hollow metal is far superior in terms of durability and features. Metal can often be found used in hinges, doors, door frames, architectural metal grilles, metal roof tiles, and many other places requiring great durability or safety. There are a large number of factors that influence what type of hollow metal should be used, and where.

These include but are not limited to projected types of usage, local fire codes, potential abuse, maintenance, impact probability, opening configurations, protective applications, corrosive conditions, cleanliness standards, frequency of use, and aesthetic preferences.

Types of Hollow Metal Applications
There are 6 different classifications for hollow metal usage. These are light duty, moderate duty, heavy duty, maximum duty, detention security, and commercial security.

  • Light duty applications are areas of a building that are not expected to be subjected to very much usage or abuse. This includes areas such as closets and offices. Frame = 18 gage 0.042” (1.06) Door = 20 gage 0.032” (0.81)
  • Moderate duty applications are those expected to meet with a moderate level of abuse, usage, and impact. This includes areas like meeting rooms, classrooms, and stairways. Frame = 16 gage 0.053” (1.34) Door = 18 gage 0.042” (1.06)
  • Heavy duty applications are expected to see high usage and a high chance of abuse and impact. This includes areas like service entrances, exterior entrances, health care facilities, and recreational areas. Frame = 16 gage 0.053” (1.34) Door = 16 gage 0.053” (1.34)
  • Maximum duty applications expect high usage and an even higher probability of impact and abuse. This includes all heavy-duty applications, as well as pharmaceutical buildings, and psychiatric clinics. Frame = 14 gage 0.067” (1.70) Door = 14 gage 0.067” (1.70)
  • Detention security applications are used for the detainment of individuals, often against their will. This includes individual cells within detention and correctional facilities, as well as uses within control and day rooms in those facilities. Frame = 14 gage 0.067” (1.70) Door = 14 gage 0.067” (1.70)
  • Commercial security applications expect to see a high threat of intrusion, ballistic attack, or forced entry. This includes places like government buildings and infrastructure. Frame = 14 gage 0.067” (1.70) Door = 14 gage 0.067” (1.70)
Types of Abuse
The types of abuse for hollow metal are low, moderate, high, and very high. Low levels of abuse include periodic bumping by limbs, typical closing and opening, cleaning equipment, and foreign objects being used to hold doors open.
Moderate levels of abuse include aggressive closing and opening, moderate exposure to wind and weather, propping open automatic doors, luggage, wheelchairs, maintenance carts, and excessive slamming.

High levels of abuse include the potential for forced entry, auto-door operators, hanging on doors, bodily impact, access control, opening doors with feet, material handling equipment, gurneys, and high weather/wind exposure.

Very high levels of abuse are defined as a high potential for vandalism and forced entry.
Choosing the Right Type of Hollow Metal
Based on the applications and classifications listed above, architects should take care to implement the correct gauge and type of metal. Following these guidelines can help prevent injury, malfunction, security threats, and other undesirable outcomes.

Matt Lee is the owner of the Innovative Building Materials blog and a content writer for the building materials industry. He is focused on helping fellow homeowners, contractors, and architects discover materials and methods of construction that save money, improve energy efficiency, and increase property value.