Suspended Ceilings: Key Construction Requirements
Suspended ceiling systems are widely used today for finishing ceiling spaces in various buildings and structures. However, designing these systems can be challenging because the current regulatory framework is not sufficiently adapted to modern realities. As a result, requirements for suspended ceiling installation must be pieced together from several disparate documents.
On the one hand, this flexibility simplifies the design process, allowing for the inclusion of virtually any dimensions or configurations in a project. On the other hand, the lack of a unified regulatory document complicates the process, as both designers and installers lack clear guidelines to follow during their work.
This article aims to address some of these challenges. For those who work with suspended ceilings, we recommend studying this material carefully and applying the information provided below in their projects and installations.
Suspended Ceiling System Construction
Suspended ceiling systems are assembled using a standardized approach:
- Foundation. The base for a suspended ceiling typically includes the ceiling slab and, in some cases, the upper portions of wall structures. Permanent structures usually serve as the foundation, though additional supports, such as beams, can also be used in some cases.
- Framework Attachment. The framework is attached to the base. In most cases, this framework is made of metal, such as galvanized steel or aluminum alloys. Wooden frames are also permissible but require metal connectors and auxiliary elements. Wooden components should ideally be treated with fire-retardant coatings to minimize flammability.
- Ceiling Panel Installation. The suspended ceiling is fixed to the framework. It can either be a continuous structure (e.g., tension fabric, plywood sheeting, or drywall) or an assembled design. For the latter, elements such as cassettes (made of plastic, metal, or composite materials), slats, grid sections, and various modular forms are used. A good example of such designs includes Mehbud factory’s metal ceilings.
The fixation method and the connections between elements depend on the ceiling design. Metal frameworks are commonly anchored to the base using bolts or other fastening tools. Ceiling modules are attached to the framework using screws or via built-in mechanisms such as slots or clips.
Regulatory requirements for ceiling construction
As mentioned earlier, there is currently no single document that consolidates the requirements for suspended ceiling construction and its elements. Therefore, when designing and installing, it is recommended to rely on the existing regulatory framework – GOST (DSTU), SNiP (DBN), etc.
Key requirements
The main document that must be considered when designing and manufacturing suspended ceilings is SNiP 3.04.01-87 “Insulation and finishing coatings” (with amendments and additions). According to the requirements of this standard:
- Suspended ceiling systems are installed on ceilings and other surfaces that have sufficient load-bearing capacity.
- Leveling the ceiling and walls, areas that will be used for fixing the frame elements, is not mandatory. However, it is recommended to eliminate large defects by repairing these surfaces, as well as treating them to prevent material damage due to moisture and mold.
- The frame construction of the suspended ceiling is determined by the project. However, it must be strong enough to prevent deformation under the weight of the ceiling elements.
- Before starting the installation of the suspended system, the plane of the frame is checked using measuring instruments.
- The installation of cassettes, panels, slats, grating sections, and other components must be carried out according to the marking, starting from one of the corners of the room. During installation, horizontal joints between components that are not provided by the project should be avoided.
- The plane formed by the suspended ceiling elements must be flat. Sagging at joints and beams, delamination, etc., is not allowed. Additionally, vibration or any other movement of elements at the points where they are fixed to the frame is not permissible.
Permissible dimensional deviations in the plane of the suspended ceiling (of any type of construction):
- The step between adjacent tiles, panels, or slats should not exceed 2 mm.
- Deviation of the suspended ceiling plane vertically/horizontally should not exceed 1.5 mm per meter, and no more than 7 mm over the entire surface.
- Deviation of the wall cladding joint from the vertical should not exceed 1 mm per meter.
- The maximum permissible deflection of the structure under its own weight should not exceed 1/250 of the span width.
In addition to general requirements for suspended constructions, other recommendations should be considered, which are provided in typical technological cards for the installation of suspended ceilings and other documents:
- For fixing the frame elements to the supporting base, adjustable and non-adjustable suspensions are used. Adjustable suspensions (with adjustable geometry) are made from steel wire (2.5-3 mm) or galvanized steel plates (0.6-0.8 mm thick). Rigid non-adjustable suspensions are made from rods with a diameter of 5 to 12 mm or from steel strips 2-4 mm thick.
- The attachment to concrete and brick surfaces is done using bracket fixing with dowel nails (with plastic or metal expansion sleeves). Installation on wooden ceilings is done using nails or self-tapping screws. Attachment to metal pipes or beams can be carried out using clamps or bolt connections.
- Engineering communications located behind the suspended ceiling plane must be fixed to the solid foundation using independent suspensions and other fasteners. Joint fixation of frame elements and communications on common suspensions is not allowed.
- The construction of a modular suspended ceiling (such as “Armstrong” ceilings or metal ceilings from Mehbud) must allow for the removal of individual elements without compromising the integrity of the entire system. The ability to remove panels is necessary for access to the space between the ceiling covering and the suspended ceiling for inspection and maintenance of utilities.
Another requirement for the suspended ceiling design concerns the installation of additional elements (primarily light fixtures and ventilation grilles). To provide the suspended structure with the required load-bearing capacity at the point where the built-in or surface-mounted lighting is installed, reinforcing elements must be incorporated into the frame.
Fire Safety Requirements
A separate group of requirements concerns the safety of buildings in the event of a fire. In this regard, it is essential to primarily refer to SNIP 21-01-97 “Fire Safety of Buildings and Structures.”
According to this document and other current regulations:
- When installing suspended ceilings in public buildings, children’s, and medical institutions, stricter requirements apply: the fire hazard class of materials must not exceed KM2 (in some cases — KM1 and KM0).
This means that materials like drywall, plywood, or wood paneling cannot always be used for ceiling cladding. However, metal suspended ceilings from Mehbud (cassette, rack, and modular) meet all fire safety requirements in the vast majority of cases.
Types of Suspended Ceilings from Mehbud Factory: Design Features
The Mehbud factory offers a wide selection of suspended ceilings that meet modern requirements for functionality, design, and durability. Below are the main types of suspended ceilings and their design features:
Cassette Ceilings
Cassette ceilings are a modular system made up of square or rectangular panels attached to a concealed or exposed frame.
Design Features:
- Easy installation and replacement of individual elements.
- Integration options for lighting, ventilation, and fire safety systems.
- Ideal for commercial spaces, offices, and shopping centers.
Cubic shaped Ceilings
Cubic shaped ceilings create a sense of depth and volume through longitudinal profiles placed at specific intervals.
Design Features:
- Perfect for spaces with high ceilings.
- Provide good ventilation due to their open structure.
- Add a stylish and modern look to the space.
Rectangular Ceilings
Rectangular ceilings offer a more strict and minimalist design, making them a popular choice for office and administrative buildings.
Design Features:
- Clean lines and minimalist design.
- Flexible combinations of various sizes and shapes of rectangular elements.
- Ideal for creating a formal and professional interior.
Rack Ceilings
Rack ceilings consist of narrow metal profiles (slats) that are mounted on a suspension system.
Design Features:
- Perfect for areas with high humidity, such as pools or kitchens.
- A wide selection of materials and finishes (matte, glossy, metallic textures).
- Easy maintenance and long-lasting construction.
Conclusion
Naturally, this is not a complete list of the requirements for suspended ceiling systems. However, if you plan to work in compliance with all regulations, this list covers the most important aspects.
You can also use the information provided above when choosing a contractor for ceiling installation or when evaluating the quality of work done by an installation team.