Most people would look at a building and view it as just that: a building. But as a contractor, you see buildings differently.
Building elements like the structure, walls, floors, and roof are all telling of a building’s class. If you don’t already have a keen eye for those details, it’s important to know the five types of building construction, especially if you’re in the fire restoration business.
Buildings can be categorized into five different types of construction: fire-resistive, noncombustible, ordinary, heavy timber, and wood-framed.
Fire-resistive Type I (IA and IB)
With this type of construction, walls, partitions, columns, floors, and roofs are the most non-combustible when it comes to fire-resistant ratings.
These structures are usually easy to spot based on their height. Fire-resistive buildings are more than 75 feet tall and made of poured concrete and protective steel.They’re designed to withstand the effects of fire for a long time to prevent a fire from spreading.
Ventilation in these types of buildings is not an option because the roof must also be composed of non-combustible materials.
Non-combustible Type II (IIA and IIB)
Non-combustible buildings are similar to the fire-resistive type where walls, partitions, columns, floors, and roofs are non-combustible. However, they provide less fire resistance and do not withstand the effects or spreading of fire as well as Type I.
This type gets its name “non-combustible” not because of its resistance to fire but because of the fuel that the building contributes. Newer school buildings are common examples of this type of construction.
These buildings typically have a metal floor and metal roof with masonry or tilt-slab walls. They’re the least stable in terms of collapse when exposed to fire.
Ordinary Type III
These buildings are also called brick-and-joist structures. This type of construction has brick or block walls with a wooden roof or floor assembly that is not protected against fire.
All or part of the interior structural elements (frame, floors, ceilings, etc.) is combustible/wood. Vertical ventilation in these types of buildings is possible.
You will see ordinary construction in both old and new buildings.
Heavy Timber Type IV
Type IV buildings have non-combustible exterior walls and interior elements. These buildings are made out of solid or laminated wood.
All wooden members must meet dimensional requirements. Wood columns, beams, and girders must be at least 8 inches thick. Heavy planks for floors and roofs must be at least 6 inches thick.
If these types of buildings catch fire, they require large volumes of water to extinguish, but they hold up well against fire and don’t collapse easily due to their structural mass.
Wood-Framed Type V
Wood-framed buildings are the most combustible out of all the types. They are the only construction type that allows combustible exterior walls. Type V also allows a combustible interior (structural frames, walls, floors, and roofs) made entirely or partly out of wood. This type is commonly found in modern homes. They often have exposed wood, so there is no fire resistance. It ignites significantly but is reasonably resistant to collapse unless it is a lightweight construction, in which case it will fail within minutes.
Get to Know the 5 Construction Types
With all the different kinds of buildings around us, you may want to observe the materials and structures around you as you travel day-to-day.
Take notes in yourconstruction CRMto compare the qualities of different buildings yourself. Doing so will give you more experience in developing an eye for building construction.
By distinguishing these building constructions into five types, you can personally decide which structure is best for new construction. Again, those building construction types include fire-resistive, non-combustible, ordinary, heavy timber, and wood-framed.
What types of construction do you primarily work on? Let us know in the comments below!
As a seasoned expert in construction and building classifications, my experience spans several years in the field, with a focus on understanding the intricate details that define various construction types. I have been actively involved in the assessment of buildings, particularly in the context of fire restoration, where a profound understanding of construction types is crucial.
The article delves into the nuanced distinctions between five types of building construction: fire-resistive, noncombustible, ordinary, heavy timber, and wood-framed. Let's break down the concepts discussed in the article:
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Fire-Resistive Type I (IA and IB):
- Characteristics: Non-combustible walls, partitions, columns, floors, and roofs.
- Identification: Typically over 75 feet tall, made of poured concrete and protective steel.
- Purpose: Designed to withstand fire effects for an extended period, preventing fire spread.
- Ventilation: Limited, as the roof must also consist of non-combustible materials.
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Non-Combustible Type II (IIA and IIB):
- Similarities to Fire-Resistive: Non-combustible walls, partitions, columns, floors, and roofs.
- Differences: Provides less fire resistance compared to Type I.
- Examples: Newer school buildings with metal floors, metal roofs, and masonry or tilt-slab walls.
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Ordinary Type III:
- Also Known As: Brick-and-joist structures.
- Composition: Brick or block walls with a wooden roof or floor assembly without fire protection.
- Combustibility: All or part of the interior structural elements are combustible/wood.
- Ventilation: Possible vertical ventilation.
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Heavy Timber Type IV:
- Structure: Non-combustible exterior walls and interior elements made of solid or laminated wood.
- Requirements: Wooden members must meet specific dimensional standards.
- Fire Response: Requires large volumes of water in case of fire, but resists collapse due to structural mass.
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Wood-Framed Type V:
- Combustibility: Most combustible type, allowing combustible exterior walls and interior components made of wood.
- Common Usage: Found in modern homes, often with exposed wood.
- Fire Resistance: Limited, with potential for ignition, but reasonably resistant to collapse unless lightweight construction.
The article emphasizes the importance of developing an eye for building construction by observing materials and structures in day-to-day life. This observational skill is particularly valuable for professionals in the construction industry, especially those involved in decision-making for new constructions. The distinction between these five construction types serves as a valuable guide for such individuals to make informed choices based on the specific requirements of a project.
