By Randy Bishop, President, Critical Facilities Solutions
There are currently 10’s of thousands, if not 100’s of thousands of server racks sitting on data center raised floors that are basically a house of cards. What do I mean by that? The major tile manufacturers limit the lifespan on floor tiles to 20 years. The longer a tile goes past its recommended lifespan the closer that tile is to potential failure. Rolling load capabilities also decrease with each rolling load.
DISA Enterprise Services did a Facility Standards study in May of 2015 and concluded that, based on their tests; the lifetime for a floor’s maximum strength is as follows:
1250 1500 2500
10 years 12 years 20 years
Note: 1,000 lb. panels were not even considered worth of testing as they were considered too low of a weight rating to merit testing.
The thought process of the study being that if the lifetime design of a 2500 panel system is 20 years then the lifetime of weaker panel systems is linearly proportional to the design strength of the panels. This was an independent study and not supported by the major tile manufacturers.
The raised floor is designed to be one continuous ‘wall to wall’ system. This provides maximum stability. Floors that have been installed independently of each other, or where a different floor system has been added without ‘tying into’ the previous floor system, are basically independent islands of floating floors and are far more prone to failure and/or collapse.
Gapping floors can also eventually lead to floor collapse. This happens when the floor tiles are no longer making full contact with the grid. As the tiles shrink back in contact they become more susceptible to falling off of the grid and/or pedestal head when weight is applied to the floor in the immediate area around the tiles.
Pedestals that are under stress from the torque caused by the twisting over time often begin to lean, or even shear off, from the weight of both static and rolling loads. As pedestals begin to lean or shear off more stress is put onto nearby pedestals and tiles, decreasing their weight capacity even further.
Tiles that are past their lifespan begin to decrease in weight capacity. As the weight capacities decrease, any other weakness or failure in the floor system is magnified.
CFS, along with our resll has been in many data centers where the raised floor was a “House of Cards,” ready to fail and collapse at any minute. Here are just a few issues either our customers have called CFS in to remedy, or CFS has found while performing other services in the data center.
- Slip fall: We have had customers’ floors collapse underneath an employee causing a slip/fall incident with injury.
- Rolling Load Collapse: Floor collapsed in main aisle way as rolling load was passing over. Luckily the collapse was localized and did not make it all the way to an equipment area.
- Equipment fell into floor: Floor collapsed underneath and/or around equipment cabinets, causing them to fall through the raised floor.
- Equipment leaning or listing: We have found server cabinets, UPS units, and PDU’s leaning and uneven due to the floor beneath failing from the weight load and/or age.
It’s unrealistic to turn off half of your servers and move racks off of the raised floor. So, what’s the solution?
In 2008 CFS helped develop a hoisting system using the concrete subfloor as a base. The hoisting system allows us to hoist multiple racks (up to 17 racks at a time), suspend them 3 to 4 inches and remove and replace all of the substructure and floor tiles with no downtime required. CFS has hoisted thousands of racks across the United States using this method. Lifting multiple cabinets allows for cabinets that are ganged together, and/or have wires and cables going horizontally through the cabinets, to be lifted at once. The ability to lift multiple cabinets also means fewer overall lifts, minimizing the risks of downtime.
We have replaced floors with zinc whisker issues, floors that were so bad floor tiles had been removed and steel plates inserted to keep the floor from collapsing, floors that were improperly installed causing the floor system to be compromised, floors that were at the end of life cycle and had deteriorating weight loads. CFS has also increased the subfloor height by 10” while replacing the floor in a legacy data center.
If you think your floors are due for an examination, don’t hesitate. Schedule a data center tile floor inspection with us today.