Let’s continue on with our discussion on the advantages and disadvantages of the various types of deck surfaces we offer on our mezzanines.  First we talked about corrugated roof deck with resindek.  We mentioned that it was an extremely versatile and cost effective solid deck type, but that as a wood composite material it doesn’t perform well in environments where it is prone to getting wet.  Next we talked about open bar grating:  an open steel deck surface that excels in outdoor/wash down environments as it allows water, snow, and debris to fall through.  While texture in the bar grating provides a very grippy surface, it makes it very difficult to move pallets across and there are times when you don’t want materials to fall through the deck.  Today we’re going to talk about a mezzanine deck surface that combines features of both of these — corrugated roof deck with steel plate.

Like roof deck and resindek, roof deck with steel plate is a solid deck surface composed of two layers.  The strength of the deck comes from the corrugated roof deck.  The steel plate is there to provide a flat surface to walk across.  Typically we use a smooth plate which allows for easy transport of pallets, carts and other rolling materials.  Every once in a while though, where this is not the plan, we’ll go with a steel plate that has a raised texture to it, providing a better grip.  It’s a very strong and durable deck surface, and being a steel deck, it holds up in potentially wet environments.  In particularly wet environments you’ll want to seam weld the deck and set up a drainage system so the water doesn’t get trapped in the corrugation.

The biggest disadvantage of roof deck with steel plate is its cost, which is comparable to open bar grating.  Many of the applications that call for a closed deck mezzanine would be equitably serviced by resindek as it would by steel plate.  The resindek would have the advantage, though, as it is significantly less expensive.  Unless it’s in a potentially wet environment or being installed in a location where no wood is allowed, you might as well save your money and go with the resindek.

Open bar grating deck surface on an observation platform.

Let’s continue our exploration into the different types of decking used on our mezzanines.  Last time we talked about corrugated roof deck with resindek.  We mentioned that as a wood composite material it can swell if soaked, so it is not the ideal deck type for wet environments.  Today we’re going to talk about one deck type that excels in wet environments:  open bar grating.

The typical grating that we use is a 19W4 bar grating.   It’s made by taking steel bearing bars placed 1-3/16” on center and joining them together by welding wire rod cross beams perpendicular to the bearing bars every 4” creating an open grid.  The grating typically has either a painted or galvanized finish depending on the application.

Serrated and galvanized open bar grating on a landing bound for the outdoors.

Galvanized and serrated open bar grating is an ideal deck solution for outdoor applications.Open bar grating has many advantages as a decking material.  It is very strong and durable, and the grated surface provides excellent traction.  For particularly slick locations, such as oil factories or outdoors in icy environments, we offer a serrated version for even better grip.  As an open decking surface it easily allows water, air, and light to pass through the system.  This is why it is a particularly popular decking material for outdoor applications.

There is one common misconception about the open bar grating that I would like to note though.  We are often asked to put open bar grating in sprinkled environments, with the customer thinking that they will not need to add sprinkler lines below the platform.  Unfortunately this is not the case.  The decking and framing of the mezzanine system occlude the area below enough (even before factoring in the materials on top of the platform) that your fire inspector will still require you to sprinkle below the deck if it is sprinkled above.

Oddly enough, open bar grating’s strengths are also its weaknesses.  As a fabricated steel material, it is significantly more expensive than the resindek.  The grated surface makes it extremely difficult to roll pallets and such around on top without adding something like a layer of plywood in order to provide it with a smooth surface to roll across.  And as an open, porous material it allows things to flow through it, such as fingers, heels, dropped hardware (i.e. nuts, bolts, screws), or spilled material.