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Fire Safety

This poke-thru device meets scrub water standards and can be installed on a tile floor. Until recently, these devices were restricted to carpeted surfaces.

Prior to the development of the newest generation of fire-rated poke-thru devices, core drilling of concrete floors required the installation of fire stopping material to maintain the floor’s fire retardant capabilities. Unfortunately, these operations could not always be adequately policed, and code enforcement agencies moved to limit the practice. The solution was to incorporate fire stopping material into the fitting itself, guaranteeing that each penetration maintains the slab’s fire rating.

The key to a poke-thru serving as a fire stop is intumescent material around the conduit stem at the slab level. When exposed to high temperatures, the material expands to fill any space between the fitting and the floor slab. In the event of a fire, the slab penetration is quickly filled by the expanding intumescent material, effectively blocking flames and heat and maintaining the slab’s fire rating.

The fire classification also identifies the number and size of conductors allowed in each poke-thru. Unlike standard conduit and raceway, the number and size of the conductors allowed in poke-thru devices is determined through fire testing procedures determined by Underwriters Laboratories Inc., and not by calculating cable fill percentages. Therefore, when choosing a poke-thru device, refer to the manufacturer’s allowable copper cross sectional area for each poke-thru device.

Communications Cabling

Manufacturers of poke-thru devices have responded to the growth and increased complexity of structured cabling systems by developing devices that easily accommodate high-performance copper and fiber optic cable. These devices feature separate channels for electrical wiring and low-voltage cabling. In poke-thru devices that support both electric service and low-voltage cabling, the electric wires are run through the conduit stem of the fitting while low voltage cabling runs outside the conduit stem through holes in the intumescent rings. In the event of a fire, these holes, like the slab penetration itself, are filled by the intumescent material.

Poke-Thru Advantages

Since poke-thru devices can be put in place at almost any time in the construction cycle after the concrete has been poured, there is a larger window of opportunity to accommodate late design changes and fluctuations in the construction schedule. Because wiring and cabling is not located in the slab, more precise measurements are possible -– when walls and other interior components are in place – to locate workstation activations.

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