> For the complete documentation index, see [llms.txt](https://enercalc.com/docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://enercalc.com/docs/sel-user-manual/appendices/appendix/appendix-b.md).

# Appendix B - Development and Lap Lengths

Reference tables for rebar lap splice lengths and hooked bar embedments per ACI 318 and TMS 402.

Lap Splice Lengths(1) and Hooked Bar Embedments (inches)

![](https://3283832020-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FiBJmBoewuy4ZcBC7RF3m%2Fuploads%2Fgit-blob-e98b73afd388ec622391277244d59d9498246480%2FAppendixB-2.gif?alt=media)

(1) Min. lap for spliced bars, in., assumes fy = 60 ksi, per ACI 318-14, Equation (25.4.2.3a).

(2) 40 bar diameters for fy = 40 ksi and 48 diameters for fy = 60 ksi

(3) Min. lap is development length x 1.3, assuming Class B splice. Cannot be reduced for stress level.

(4) Assumes standard hook and not reduced by ratio As (required) / As (provided).

Note that IBC 2018 Section 2107.2, offers an alternative to TMS 402-16, Section 2.1.7.7.1.1. If the alternative is used, it replaces the following development length equation in TMS 402:

![](https://3283832020-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FiBJmBoewuy4ZcBC7RF3m%2Fuploads%2Fgit-blob-bf252c1dd8bbece840504edcf08eefacede13b02%2FAppendixB-1.gif?alt=media)

g = 1.0 for #3, #4, #5 bars, 1.4 for #6, #7, and 1.5 for #8

K = Smallest of (minimum masonry cover, the clear spacing between adjacent reinforcement splices, and 9 db

This requirement resulted in much longer lap lengths and has met with considerable objection.


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