Article No: 131

2006-05-02 13:32:22
Tech Talk
By: Ed Sauter


Editor's note: As part of our partnership with the Concrete Foundations Association, the following article by Ed Sauter, executive director of the CFA, is the seventh in a series on the basics of concrete foundation construction.

Concrete professionals, today more than ever, want a reliable source for regulations and industry standards and ways to improve their market area for concrete foundation development. The Concrete Foundations Association (CFA) advocates in various ways for the industry, including the development of a professional standard to provide a measurable baseline for quality performance in residential concrete construction.

The CFA Standard
The residential concrete foundation industry is anything but a new market. Contractors have taken over businesses from their fathers who took over from their fathers. In many respects, the business of solid concrete foundations is perhaps one of the last "solid" family business operations in the industry. One frequently maligned identity created by this type of history is that of resistance to change. However, concrete foundation professionals throughout North America are proving that using quality standards in their business can assist in staying ahead of the changing landscape of the residential codes and aid them in increasing market positioning and improving communication with local jurisdictions.

The impetus for a CFA Standard was generated through consecutive annual summer meetings where contractor members were expressing frustrations of working in markets with little or no code development and little or no understanding of concrete foundations. This frustration was coupled with concern for the significant timeline associated with the consensus process used to develop legal building codes.

Thus the CFA formed a Standard sub-committee that included engineer and contractor members. This committee was charged with various issues surfacing in the market and code provisions that were in obvious conflict with the truer performance of concrete foundation walls to create a document that established a firm position on the minimum standards for this quality product. "The market response has been astounding," said Terry Lavy of Lavy Concrete in Piqua, Ohio, CFA's current president. "In addition to our contractors taking the momentum created by this Standard, we have seen areas where state associations have come to the aid of foundation contractors and used this Standard to improve working conditions and the recognition of poured concrete walls."

Firm positions, established by the CFA Standard, developed both quality standards and references for the position of the industry, include the following conditions. (More are referenced throughout the document, several of which have been addressed in previous issues of this column.)

* Reinforcement contaminants
One significant issue affecting contractors during inspections is the presence of contaminants — such as rust, mill scale, form release agents and concrete splatter — on reinforcing. Testing provided over the past few years by other industry experts has demonstrated how such contaminants will not adversely affect bond or reinforcement performance. In addition, a large percentage of the poured foundation market can be constructed with "plain structural" walls, defined in the Standard as structural concrete without reinforcement or with reinforcement less than the minimum required by ACI 318 for reinforced concrete. Therefore, the CFA Standard states that such a condition shall be considered satisfactory. This is currently an acceptable position in many jurisdictions and yet often called into question when inspectors intend a strict interpretation of ACI 318 as referenced by the International Residential Code (IRC).

* Addition of water
It is automatically assumed that residential contractors increase the working slump of concrete through the addition of water onsite. However, the CFA recognizes the professionalism of today's foundation contractor by including reference to the prevention of adding water to a mix onsite to make it easier to work into the form. Specifically, the CFA Standard states that when the concrete slump on site is less than the maximum measured allowable slump and the water/cementitious ratio from the batch plant was equal to the maximum allowable, the working slump shall be increased by using an HRWR or MRWR only. "Water shall not be added to ready-mixed concrete at the job site unless the water/cementitious ratio at time of batching is below the maximum allowable" — Section 5.4. This provision provides practical guidance for the contractor but also recognizes an abuse pattern that concerns engineers and inspectors.

* Foundation shear transfer
The connection of the foundation wall to the footing is often a key point of discussion between contractors and inspectors. The idea of "proper" connection is one that can be handled in various ways. The CFA Standard directs the user to consider two allowable methods when, and only when, the floor slab is not in place prior to backfill and the backfill height exceeds 4 feet or when backfill is not intended to be equivalent on both sides of the wall. In conditions other than these, the foundation connection shall be made through the use of a dowel between the wall and footing or the use of a keyway formed in the footing. When using a dowel to provide shear connection, the contractor is allowed to drive the dowels into the prepared excavation prior to placement of the footing concrete or into pre-drilled holes in a previously prepared footing. In addition, the spacing of those dowels is permissible to be a maximum of 48 inches.

Putting the Standard to work
Although the CFA Standard was not developed by such recognized code associations as the International Code Council or the American Concrete Institute, the provisions of the Standard are becoming recognized as effective points of consideration for the development of markets and the establishment of a level of quality where no other provision has existed.

One example of recent influence is cited from Solon, Ohio, where the city had previously amended the provisions for foundation wall construction in the IRC by prohibiting the construction of foundations with poured concrete walls. Foundation contractors in the area collaborated with the Ohio Ready Mixed Concrete Association (ORMCA) to investigate the issue. ORMCA quickly contacted the CFA for assistance in the matter and the CFA Standard was provided to the city as a reference for the minimum design and construction standards allowable for poured foundations. Recognizing the asset of this document for providing control to a market they believed was without standard or control beyond the provisions in the IRC, the city offered an amicable resolution by striking the restrictive language from their amendment.

The CFA Standard has also been used effectively to effect change at a state level. A homebuilder from Cincinnati, Ohio realized that the state's adoption of the IRC would unnecessarily increase the thickness of the concrete foundations in his area, thus substantially increasing the cost of their foundations. This builder, through a partnership with a local CFA foundation contractor member, received a copy of the CFA Standard. After comparing the two documents, they made a recommendation to the state to amend the state code's adoption by referencing the wall thickness tables of the CFA Standard. A thorough review by the State's Board of Review and supported by the ORMCA, led to the adoption of the proposed amendment.

Industry associations such as CFA are an invaluable resource. CFA works on behalf of our members and the entire industry to develop, support and influence code bodies. CFA also represents member interests on several code and regulatory bodies, including the ACI code for residential concrete (ACI-332) and cold-weather concrete standards (ACI-306). Our goal is to also teach members how to interact with code officials. As such, we offer educational seminars and counsel on how to affect local code bodies and processes.

Established in 1974 for the purpose of improving the quality and acceptance of cast-in-place concrete foundations, the CFA has a variety of resources on this topic. In addition to providing promotional materials, educational seminars, opportunities for networking and a telephone network that places members in one-on-one contact with an experienced contractor for assistance in resolving various issues, the CFA represents the interests of its members and the industry on several code and regulatory bodies, such as the ACI's committee (ACI-332) responsible for the creation of the "Residential Concrete Standard." Once complete, this standard will likely be adopted by the IRC. The CFA has several members on the ACI committee responsible for this document and will endeavor to ensure that the interests of the foundation contractors are considered.

Ed Sauter is executive director of the CFA. For more information, call 319-895-6940 or see www.cfawalls.org.