> For the complete documentation index, see [llms.txt](https://docs.enercalc.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.enercalc.com/sel-faq/using-the-software/calculation-modules/foundations2/general-footing/rebar-placement-and-the-minimu.md). # Rebar Placement and the Minimum Steel Calculation How the General Footing module handles top and bottom rebar mats and the minimum reinforcing area calculation. ## How does the module handle top and bottom rebar mats and the minimum reinforcing area calculation? The General Footing module provides inputs for number and size of bars parallel to the x axis and parallel to the z axis for the bottom mat. If the Specify Top Reinforcing checkbox is selected, the module offers separate input fields to collect top rebar size, count, and clear cover. When the footing is loaded with downward loads so that the tension is on the bottom, the resulting moment will be compared to the moment capacity assuming that the specified bars are located on the bottom of the footing. The program automatically incorporates the minimum reinforcing check from Section 7.6.1.1, and the commentary to Section 7.6.1.1 is clear that this amount applies independently to each tension surface. If a footing happens to be subjected to net uplift so that tension occurs on the top, there is now an option to specify a top mat of reinforcing. When a top mat is specified, the resulting moment will be compared to the moment capacity assuming that the specified bars are located based on the specified top clear cover. Top mat results will also consider the minimum reinforcing requirements from Section 7.6.1.1. The Footing Bending tabs still clearly indicate which surface is in tension, so you can quickly decide whether you need to specify a top mat or not. {% hint style="info" %} Note: ACI is now clear that Section 7.6.1.1 provides a minimum steel ratio for footings. The value is typically 0.0018Ag. This is NOT temperature and shrinkage reinforcing. This is a minimum amount of flexural reinforcing that must be provided, and in situations where top and bottom mats are specified, this amount cannot be split between the two mats. The commentary to Section 7.6.1.1 is clear that this amount applies independently to each tension surface. {% endhint %} --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter: ``` GET https://docs.enercalc.com/sel-faq/using-the-software/calculation-modules/foundations2/general-footing/rebar-placement-and-the-minimu.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.