Vertical rebar positioners

Words: Mike Ripley/Public/News/20120519070000-1.jpg" width="600" height="338" border="0" alt="Vertical rebar positioners aid the mason contractor in centering the bars in the core of the block." />
Vertical rebar positioners aid the mason contractor in centering the bars in the core of the block.
Vertical rebar positioners have been part of the masonry accessory package for many years. They add no structural value to the wall, but aid the mason contractor in centering the bars in the core of the block and also help to simplify the lapping process.

The most popular and economical positioners for vertical applications are the Figure 8 or S type and the O ring. They are installed perpendicular to the plane of the block crossing the core with the wire loops centered. Positioners are set in the mortar of the bed joint for stability and vertical spacing is about every four feet.

Placement tolerances for single rebar applications are listed in Specification for Masonry Structures (TMS 602-08/ACI 530.1-08/ASCE 6-08) under Part 3 — Execution 3.4 B.8. Working from the center point of the core you are allowed + ½ inch in the width or thickness of the wall and 2 inches along the length of the wall. This leaves you a space in the core center of 1 inch wide by 4 inches long to be code compliant for vertical applications.

Some masons install bars manually (by sight) and others with the aid of positioners but all with the risk of not meeting code. While the use of rebar positioners greatly narrows the margin of error, they also move during installation due to sitting on top of the shelf of the CMU and moving when mortar or the next course is applied.

A new trend in vertical rebar positioners has emerged to solve the movement issue during installation. Core inserted positioners, which are designed to fit 1½-inch deep, cross the core diagonally and fit tightly in the corners of the core. The core positioners perfectly position the bars in the code compliance zone and allow no movement during installation. They also have an extended tail section (safety bend) so if installed incorrectly (out of plane), the tail will extend outside the wall alerting the mason to turn it in the opposite position.

Double vertical core positioners are also available but with a different design, spacing the loops or guides closer to the face shell of the CMU. To complete the family there is a bond beam positioner that positions bars in the lower one-third of the unit and ½-inch off the inside face shell.

Take the guesswork out of rebar placement by using the core inserted positioners.
Building the Future: NCMCA’s Success in Apprenticeship Across North Carolina
October 2026

THE PAST How the Groundwork Was Laid to Build the Future of Apprenticeship Across North Carolina My Registered Apprenticeship began in the early 90’s. I went back to the archives and dug out a few pictures of my apprenticeship pathway. In 1992, as an a

Means and Methods: A Testimonial is More Than a Review
October 2026

A positive review can tell someone that a user is satisfied with the brand. A detailed testimonial can tell them why. When professionals speak about their experiences, they not only go into the features of the product but also focus on the challenges elim

3 Promise Labor Services Continues as a Gold in 2027
October 2026

The Mason Contractors Association of America (MCAA) is happy to announce that 3 Promise Labor Services will continue as a Gold Partner in the 2027 Masonry Alliance Program.

Kraft Tool Co. Returns as a Silver Partner in 2027
October 2026

The Mason Contractors Association of America (MCAA) is pleased to announce that Kraft Tool Co. will return as a Silver Partner in the 2027 Masonry Alliance Program.