Tn 18A web-nov06. indd

Expansion Joint Sealants:

• Comply with ASTM C 920, Grade NS, Use M

• Class 50 minimum extensibility recommended; Class 25 

alternate

• Consult sealant manufacturer’s literature for guidance 

regarding use of primer and backing materials 

Bond Breaks:

• Use building paper or flashing to separate brickwork from 

dissimilar materials, foundations and slabs

Loadbearing Masonry:

• Use reinforcement to accommodate stress concentrations, 

particularly in parapets, at applied loading points and 

around openings

• Consider effect of vertical expansion joints on brickwork 

stability

© 2006 Brick Industry Association, Reston, Virginia 

Page 1 of 11

INTRODUCTION

A system of movement joints is necessary to accommodate the changes in volume that all building materials 

experience. Failure to permit the movements caused by these changes may result in cracks in brickwork, as 

discussed in Technical Note 18. The type, size and placement of movement joints are critical to the proper 

performance of a building. This Technical Note defines the types of movement joints and discusses the proper 

design of expansion joints within brickwork. Details of expansion joints are provided for loadbearing and 

nonloadbearing applications. While most examples are for commercial structures, movement joints, although rare, 

also must be considered for residential structures.