During placing the steel in RC structure if the required length of a bar is not sufficiently available to make a design length then lapping is done.

Lap length is the minimum length that must be provided if two bars are joined together such that forces can be transferred safely.

###### Lap length of reinforcement bars:

- Flexural tension – Ld or 30d whichever is greater.
- Direct tension – 2Ld or 30d whichever is greater.
- Lap length in compression shall be equivalent to the development length in compression computed but not less than 24d.
- Different diameter are to be spliced, the lap length is calculated on the basis of smaller diameter bar.
- Lap splices should not be used for the bars having larger dia than 36mm.
- Lap length for Columns – 45d.
- Lap length for Beams – 60d
- Lap length for Slabs -60d.
- Example for if we need to lap 20mm dia column bars, we have to provide a minimum lap of 45 * 20 = 900mm.