---
title: Floor Slab Flatness and Levelness
description: "Flatness, Levelness, F-Numbers, Straightedge: What do the numbers mean? Recent changes to ACI 117 provide new procedures for straightedge measurements for floor slab flatness. Under the revised standa"
---

[Blog | conspectusinc.com ](https://www.conspectusinc.com/blog)

# [Floor Slab Flatness and Levelness](https://www.conspectusinc.com/blog/2010/07/floor_slab_flatness_and_levelness)

 Written by [David Stutzman](https://www.conspectusinc.com/blog/author/david-stutzman) | 7/27/10 10:00 AM

Flatness, Levelness, F-Numbers, Straightedge: What do the numbers mean? Recent changes to ACI 117 provide new procedures for straightedge measurements for floor slab flatness. Under the revised standard, 1/8 inch in 10 feet is not a standard option. Learn what each term means and how to specify floor slab tolerances in accordance with industry standards for each floor surface classification.

Visit our website at [https://www.conspectusinc.com/publications.htm](https://www.conspectusinc.com/hubfs/Conspectus%20Tech%20Tips%20A4010%20Floor%20Slab%20Flatness%20%26%20Levelness%20rev10.12.29.pdf) to view or download A4010-Floor Slab Flatness & Levelness 10.07.01.

Share your opinions and comments about this month's Tech Tips, by leaving a comment, here.

[View full post](https://www.conspectusinc.com/blog/2010/07/floor_slab_flatness_and_levelness)

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