FIND A CONTRACTOR BUYER'S GUIDE
BECOME AN INDUSTRY PARTNER
MCAA Logo
MEMBER LOGIN JOIN
NEWS
2026 Midyear Meeting Registration is OPEN ↗

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.
 0
Masonry in the Media: Casa Azul, Chapultepec Castle, & More
June 2026

A film’s settings can take viewers to new locations, all from the comfort of their own home. It immerses them in the scenes, whether they take place in an opera house in Brazil or a grand mansion in Mexico City. Explore how these Latin American masonry ma

Lily Burger
Masonry in the Media
Read More
Chairman’s Message: When Things Don’t Go as Planned
June 2026

Not every day in this business goes the way we planned. Some days, everything lines up. The crew is moving well. Materials are on time. The job is flowing the way you hoped it would. And then there are the other days. The ones where something breaks. T

Kent Huntley
Chairman’s Message
Read More
Marvelous Masonry: Borobudur
June 2026

For masonry contractors and suppliers, few structures offer as much practical insight as Borobudur. Built in the 9th century in Central Java, this massive stone monument remains as one of the most advanced examples of large-scale masonry construction ever

Cassandra Stern
Marvelous Masonry
Read More
Wrapping Up Our Year And A Look Ahead
June 2026

It is amazing another year has gone by and what a year it has been. We have seen a lot of progress on so many fronts. All of this happens specifically due to the support of our members. Your support this past year is positioning our industry to make huge

Jeff B
President's Message
Read More