Any successful warehouse operator will tell you that the most effective system of material handling is the one that provides the most immediate access to inventory and allows its movement from storage rack to shipping dock, at the lowest cost, in the shortest possible time. Higher performance, lower costs and safer working conditions are an integral part of Duron's Superflat floor design and installation.

Almost 30 years ago, Duron became the first contractor in the World to achieved certified Fmin100 "Superflat" floor tolerances. Since that time we have completed over 100 defined traffic floors, for various industries, around the World. Our methods of constructing these very unique surfaces include the use of highly trained finishing mechanics, specialized materials and equipment, and the use of non-standard details to produce exceptional floor surfaces which are both economical and efficient.

The foundation of our installation process includes a thorough review of the Owner's usage to develop a design that works. Our customized procedures include: formwork design, slab reinforcing, concrete mix development, placing methods, finishing techniques, and surface hardening. No stone is left unturned and all of our experience is brought to bear on the pre-construction design and planning for these critical surfaces.

Superflat are constructed to far tighter tolerances than conventional floor slabs (FF20/FL20) using a specialized defined traffic floor tolerance system call "Fmin" (F minimum). The table below exhibits the induced tilt at the maximum elevation for different picking heights with a relatively common 6mm floor tolerance from one side of the aisle to the other. These variations in transverse, as well as longitudinal, elevations over the wheel track of the forklift equipment causes significant operational concerns including dropped merchandise, higher equipment maintenance and rack impact in severe cases. The problems caused by an out of tolerance concrete floor surface have caused significant safety, operational and maintenance concerns that are completely avoidable.

Height of Racking:	6 m	7 m	8 m	9 m	10 m
Induced Mast Tilt:	24 mm	27 mm	32 mm	35 mm	40 mm

The control of both transverse and longitudinal tolerances is done by pouring the concrete in narrow strips using accurately set formwork, specialized materials and finishing techniques. As exhibited below, these actual floor profile graphs indicate the actual elevation differences over a 25' length between a good quality random traffic floor (FF30/FL20) surface and a Superflat floor (Fmin100).

FF 30 / FL 20

FF 110 / FL 117

The FF30/FL20 (flatness/levelness) floor profile [on the left] is a relatively flat, random traffic, common warehouse floor specification. The Fmin100 floor profile [on the right] is used for defined traffic, "Superflat" operating environments. By definition, a true "Superflat" floor is defined as a minimum of FF100/FL100 but this definition has changed over time to include the entire range of defined traffic floor tolerances (Fmin40 to Fmin100) and the varying wheel bases of various materials handling equipment in use today. The special "Fmin" system of tolerance definition and measurement is used for these defined traffic floors and require the correction of any transverse and longitudinal defects which are even a thousandth of an inch out of tolerance.

While the tolerance definition for each particular environment is somewhat complex, the following table provides a rough approximation of the Fmin tolerance requirements for any floor based upon the maximum rate of change per foot of travel in the longitudinal direction (available from the lift truck manufacturer):

"Maximum rate of change in inches"	0.040"	0.050"	0.060"	0.070"	0.080"
Approximate Fmin Tolerance	Fmin100	Fmin80	Fmin65	Fmin55	Fmin50

Superflat Essentials:

We strongly recommend the following points to building owners and their representatives when specifying and designing Superflat floors:

The floor tolerances must be measured on a daily basis after each pour using highly sensitive "Profilograph" equipment. If the floor isn't certified by FACE Consultants (Tel: 859-276-4372), then the floor can not be certified to meet the specifications.

Transverse contraction joints can create great tolerance losses through drying shrinkage curling that can reduce the installed tolerances by up to 50%, rendering the floor un-useable.

Design for shrinkage stresses as well as applied loading. Longitudinal drying shrinkage stresses create cracking which must be restricted in width to minimize repairs and maintenance costs.

If the floor is for AGV traffic, then Fmin tolerances apply - NOT FF/FL. FF/FL is for random traffic and not defined wheel path traffic. FF/FL do not address the longitudinal and transverse tolerances which are critical for avoiding future picking problems in very narrow aisle rack configurations.

Strip pouring is mandatory. Construction methods for AGV environments necessitate the use of strip pour techniques because of the difficulty in achieving these very demanding longitudinal and transverse tolerances.

Both short and long term savings on rack installation, turret truck operations, maintenance costs and material handling efficiency more than justify the cost of constructing a Superflat Floor. Specialty grinding operations to create Superflat tolerances in regular floors can cost as much as three times the cost of installing a well constructed Superflat floor.

Since 1959 we have built our reputation upon our total commitment to our customers and the quality of our floor finishes. Our commitment and experience guarantee the success of each of our Superflat Floor installations and we invite you to e-mail or call us for a free consultation on your flooring requirements.

Duron Ontario Ltd., A Certified Quality Contractor 1860 Shawson Drive, Mississauga, Ontario, Canada, L4W 1R7 Tel: (905) 670-1998 Fax: (905) 670-4662