Wednesday, January 14, 2015

Swimming Pool Reinforcing Steel Non-Contact Lap Splices

Pool Expert Witness discusses the importance of non-contact lap splices in reinforcing steel (rebar) for shotcrete (gunite) pool structures.

Since most concrete swimming pools are constructed out of shotcrete (sprayed concrete, sometimes also incorrectly called "gunite"), the placement of the reinforcing steel is critical.

Placing bars adjacent to each other (contact lap splice) is permissible for poured or cast concrete structures.  It is easy and efficient.

Contact Lap Splices

In sprayed concrete applications, contact lap splices can cause shadowing, honeycombs and voids within the structure.  

If the contact lap splices are stacked & orientated towards the direction of the sprayed concrete, shadowing will be minimized.  

However, this will also cause the reinforcing steel to be thicker, resulting in the use of additional concrete (equal to the thickness of the stacked bars).  On a large project that additional concrete cost could be substantial.

Non-Contact Lap Splices

A simpler and more economical method is the non-contact lap splice method.  Bars from opposing directions are staggered and separated by two to three inches.  This allows the concrete to encase and encapsulate each bar and virtually guarantees no voids behind groupings of bars.

 Both Contact Lap Splices and Non-Contact Lap Splices can be seen in the above image.  It is not particularly important on this project, as the floor will be cast in place concrete.

Contact the author, Paolo Benedetti of Aquatic Technology Pool and Spa at: or 408-776-8220. 
Visit his website at: 
All Contents © Aquatic Technology Pool & Spa, 2013. 
All rights reserved.
Aquatic Consultant, International Pool Designer, Pool Construction, Watershape Engineering

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To contact the author, Paolo Benedetti of Aquatic Technology pool and Spa, email him at: or call 408-776-8220.
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