SUPER FLAT TOOLS

Many of today's industrial buildings call for extremely tight floor tolerances to accommodate innovations in automated and material handling equipment. Concrete International has reported the concrete industries progress in meeting the demand for superflat and level floors and the methods developed to measure them. ACI committees have produced documents to guide those involved in all stages of floor design and construction. The technology for flat and level floors has increased requirements on craftsmanship and tools. Cleform Tool Corporation designs and manufactures tools capable of meeting the most exacting specifications.

Conventional floors are easily produced by old methods and products. Most floors are still floated with a 48" magnesium bullfloat. These tools and methods are readily accepted in non-commercial or residential concrete construction. When floors are placed they must be measured for adherence to specification. These measurements consist of length, breadth and thickness and also consist of floor measurements that refer to the flatness of the floor in relation to the levelness of the floor. "Straightedge Specs" (also referred to as 1/8 per 10 feet) don't have the controls needed to meet the exacting standards to control floor profiles. These flatness/levelness measurements are referred to as F-numbers. Hence, the numbers refer to floor flatness (FF) and floor levelness (FL).

Flatness refers to the bumpiness of the floor and levelness refers to the tilt or pitch of the floor. The HIGHER the F-number, the better the characteristic of the floor. The numbers are linear so a FF20 will be twice as flat as an FF10 but only half as flat as an FF40. Slabs on grade are normally specified with the FF first and a FL following such as: FF 25 / FL 20. (A simple way to view the difference in the F-numbers is to view them in this manner: FF=finishing (bumpiness) and FL = forming and strike-off resulting in tilt and pitch or grade).

The F-number system is used on 99% of all floors that support random traffic whether they are pedestrian or vehicular traffic. In other slabs in which vehicles are restricted in their movement by wire or rail guidance a different F-number is used called Fmin. Floors using a specification of a Fmin are called "super flat" slabs and are placed in long, thin sections to guarantee conformity with the given specification. Super flat floor slabs call for an FF100 / FL 50 or Fmin 100. ACI mandates F-number measurements be taken within 72 hours of the slab being placed.

Achieved floor tolerances decline as the concrete dries in jointed floors due to the curling of the slab edges caused by the drying shrinkage of the concrete. Tolerance losses of up to 50% may occur. Floor levelness tolerances do not apply to cambered or suspended floor slabs. Floor tolerances must be measured within 72 hours following construction if they are also used for conformance's purposes.

The basis of the mathematics for the FF/FL system is data that is collected uniformly across the placement area and statistically averaged to arrive at a final overall "F" number. Flatness tolerances are improved by the reducing the frequency and amplitude of the bumps and valleys on the surface of the floor. These higher tolerances are attained by using special placing and finishing techniques and tools. Cleform Tool Corporation designs and manufactures tools capable of meeting these higher tolerances.

EXAMPLES:
Occupancy FF FL
* Offices with fixed partitions, school classrooms, retail 20 17
* Offices with precut moveable partitions 30 25
* Gymnasiums with special floor systems 40 30
* Ice rinks, television studios, narrow aisle warehouses 100 50

The Reason for Using the F-Number System
The F-number system provides a rational means for specifying floor flatness and levelness and can be tailored to the tolerances required for any particular project. Using the F-number system will generally also produce an economical floor system with realistic tolerances that can be met by the contractor and also be measured by the architect.
Super Flat Floors are achieved by technique, talent and the right tools. For higher flatness requirements the Cleform Channel Radius Float replaces the standard bullfloat. The channel radius float alone significantly improves floor flatness. Multiple passes are required to produce higher levels of flatness.

The Cleform H Style Reinforced Check Rod is used immediately after the fullfloating operation. This early entry-restraightening tool starts the process of bringing the floor flatness up to the desired specification. The 90-degree edges are used for cutting and filling surface imperfections. Tool progression and multiple passes increase levels of flatness and make each operation simple.

The Cleform H Style Reinforced Bump Cutter, sometimes called the highway screed or highway straight edge is used as soon as the surface of the concrete will support the weight of the tool. The bump cutter is used for the cut and fill operation. As soon as the concrete sets to higher levels of hardness, the bump cutter is used in multiple passes until all voids and high spots are removed. The bump cutter is frequently used between the power float and troweling operations to restraighten the floated surface.

The Cleform H Style Reinforced Saw Beam is used to 'cross rod' or transverse strike off the surface by straightening and filling with the sawing action. The operator handles are uniquely designed for maximum leverage and applied surface force. The 2" x 5" beam is also available with optional tension kit in lengths up to 24'

Additional information on superflat tools available from:
CLEFORM TOOL CORPORATION 4343 Easton Road St. Joseph, MO 64503 PH: (800) 253-3676 FAX: (888) 253-3676

Additional measuring information may be obtained from:
FACE Company 427 W. 35th St. Norfolk, VA 23508 PH: (800) 368-6237 FAX: (757) 624-2128

---

Marshalltown Company
104 S. 8th Avenue
Marshalltown, IA 50158
E-mail: cleform@marshalltown.com
Hours: 8:00 am - 5:00 pm CST
Sales Office Phone: 800-888-0127 (Toll free in the U.S. and Canada)
Sales Office Fax: 800-477-6341 (Toll free in the U.S. and Canada)
Local Sales Office Phone: 641-753-0127
Local Sales Office Fax: 641-753-9227