Each is unique when it comes to its code requirements, but in this article, we will discuss the mezzanine code requirements in section 505.2. The upper mezzanine is the one that is automatically considered a floor at the height of the building, according to the wording of sentence 126.96.36.199(5) (this was a mistake in my blog), but I interpret the NBC to mean that one of the superimposed mezzanines is considered a mezzanine and the other must be considered a mezzanine, whether above or below the first mezzanine. However, the mezzanine must comply with the rules relating to the floor area in which it is located. For example, it should not exceed 10% of the floor area of the floor in which it is located. The mezzanine can be located on the upper floors of a building. For example, a mezzanine could be located on the 4th floor of a multi-storey building. The first step in determining the classification of a mezzanine is to evaluate the area of the room under consideration. This process consists of finding the ratio of the mezzanine surface to the surface of the room or room in which the mezzanine is located. To determine these two areas, IBC establishes the following guidelines: A mezzanine is defined in the Building Code as “an intermediate floor arrangement between the floor and ceiling of a room or floor and includes an interior balcony.” Whether the floor mounting is a mezzanine or a second floor affects the overall classification of the building as well as the requirements for this raised floor set, including exits.
While there have been significant revisions to the National Building Code (NBC) since the 1995 issue that have made the requirements more concise and easier to follow, it is still one of the areas of the Building Code that continues to baffle designers. There are four main considerations when designing a mezzanine. While there have been significant revisions to the National Building Code (NBC) since the 1995 issue that have made the requirements more concise and easier to follow, this is still one of the areas of the Building Act that continues to baffle designers The British Columbia Building Code (BCBC) (and possibly other codes amended by the province) has significantly different wording from the NBC for the mezzanines open at 40% described above. In the BCBC, a mezzanine “shall not be considered a floor when calculating the height of the building, unless less than 60% of the horizontal plane separating the mezzanine from the room or the floor area in which it is located is open”. This is generally interpreted as allowing closed spaces in the space in which the mezzanine opens, as long as the ceiling of these rooms is below the horizontal plane of the mezzanine. This is not how the NBC is formulated or applied, and seems to contradict the intention to ensure visual communication between those on the mezzanine and the open floor area to which they belong. The rest of all of the BCBC`s mezzanine requirements described in this document are similar to those of the NBC described below. Without going into details, there are a few exceptions in the code that allow the mezzanine to be larger under certain factors such as the construction of the building and if the building is equipped with an automatic sprinkler system and an emergency communication system. A mezzanine is a common design feature found in all types of buildings. Some commons are warehouses, factories, assembly halls, etc.
The building code outlines some basic rules for mezzanines to determine if they are an intermediate level in the space in which they serve or if they are considered a different story. The assessment of mezzanine area varies from case to case, but the process of determining the mezzanine area and the area of the room or room in which the mezzanine is located remains consistent across all arrangements. – A mezzanine must be open or closed to the room in which it is located, depending on the load of the occupant or the number of exits that serve the mezzanine space, as indicated above. If there are no other mezzanines upstairs, no other mezzanine above the one in question, the mezzanine does not exceed 40% of the open area of the room in which it is located and is relatively open to the room in which it is located above the mezzanine without partitions or partitions. secondly, the floor set is a mezzanine and not a floor at the height of the building (sentence 188.8.131.52.( 3), Department B NBC). Mezzanines are common features that can be incorporated into the building design to provide additional floor space and open spaces at an average height between two floors. There are a number of regulations that set out criteria for regulating and restricting the way the mezzanine is built. These provisions limit the overall risk of the mezzanine and affect the means of exit, the coverage of the fire protection system, accessibility, the structural nature, the opening and the permissible surface of the mezzanine. Once the areas described above have been determined, the total area of a mezzanine or mezzanine inside a room or room shall not exceed one of the following values (IBC § 505.2.1): Alternating stairs and spiral staircases may be used as means of exit for the mezzanine or equipment platforms in certain circumstances.
Sorry Doug – I didn`t see your comment until Kelsey responded. I agree with Kelsey`s interpretation. Sentences 2 and 3 are exceptions to sentence 1. If all the requirements of sentence 2 are met (sentences a to d), only one open exit staircase from the mezzanine is allowed. If this is not the case, sentence 3 is applicable, provided that the mezzanine does not have to end in a vertical separation against fire. It is rare that a mezzanine is necessary to end with a vertical separation from the fire, but can occur in large buildings with mezzanines with an area of more than 500 m2. The total area of a mezzanine inside a room should not be more than 1/3 of the floor area of the room in which it is located. IBC allows the use of alternating steps and spiral staircases for certain types of mezzanine.
The following table describes the authorized use of each device for mezzanine access. What determines whether a high-floor assembly is considered a mezzanine or a second-floor assembly? For some, it may seem quite simple – a mezzanine is open to the floor like an indoor balcony, and a second floor is not. Or even more simply, the raised floor area should be called a mezzanine. In practice, it`s more complicated than that. The first question to ask is always, what is the advantage of the structure? If it is exclusively mechanical devices or systems, it is likely a device platform or gateway and must meet OSHA`s runway requirements. Another use is a mezzanine that must have iBC compliant industrial stairs. IBC industrial stairs are listed below. The addition of partitions in the room where the mezzanine is located or in the mezzanine itself can result in the mezzanine no longer being considered a mezzanine, triggering further requirements related to the abandoned and vertical finishing of the floor set. Sentence 184.108.40.206. (7) permits an enclosed space in that relatively open mezzanine, but requires that the confined space not exceed 10% of the open area of the space in which the mezzanine is located and be arranged in such a way as to facilitate visual communication between the open space above the mezzanine and the space in which the mezzanine is located, and not disabled. Note that sentence 220.127.116.11. (3) allows the opening of shelves in libraries.
Section 505 of the International Building Code sets out requirements for two types of raised floor surfaces. These elevated floors are known as mezzanines and equipment platforms. The clear height above and below a mezzanine should not be less than 7 feet. A mezzanine must be open to the room in which it is located, with the exception of walls that do not exceed 42 inches in height. Hi Lara, Thank you for this timely post! I am currently working on a code review with mezzanines. In your contribution, you say: “If a mezzanine is partially or completely superimposed above another level of the mezzanine, the lower mezzanine is considered a floor at the building level (sentence 18.104.22.168.( 5)). I wonder why it is the lower mezzanine that should be considered a floor and whether the second mezzanine can ever be considered a floor instead? If the lower mezzanine is considered a mezzanine, wouldn`t it be the second floor and the upper mezzanine should also be considered as a floor, which gives a 3-storey building? But if the upper mezzanine was considered a mezzanine, you would have a 2-story building with the first floor with a mezzanine. .