About Operative Plasterers' and Cement Masons' Local 598

Cement Masons

A Cement Mason is a tradesman who works with concrete. The job entails placing, finishing, protecting, and repairing concrete in engineering and construction projects.

Restoration Steeplejack

A Steeplejack is a tradesman who scales buildings, chimneys and church steeples to carry out repairs or maintenance. Steeplejacks erect ladders on church spires, industrial chimneys, cooling towers, bell towers, clock towers, or any other high structure.​​


A waterproofer is a tradesman who works with many types of waterproofing membrane systems, which may include felt paper or tar paper with asphalt or tar, other bituminous waterproofing, EPDM rubber, Hypalon, polyvinyl chloride, liquid roofing and more.

Roads & Bridges

A road and bridge builder is a combination tradesman of all three trades, cement mason, restoration steeplejack, and waterproofer. They use multiple skills in performing their duties from demolition to construction.

Our Values




Union Overview

We don't typically engage in hyperbole, but we will say that no matter what construction problem you have, we've already been part of the solution.

When you've been in business as long as we have, with increasingly rapid developments, you learn a few things. Or, in our case, more than a few. We not only have simple, ready-to-implement solutions for almost every problem, and if you bring us something new, our contractors would love to work with you to find the solution. 

Historical Restoration

We remember the old days when tradesmen meant something. We've seen and been part of every aspect of Historical restoration in Ontario. Our members and contractors are the best at Restoration. Jointly with our contractors, we train our members to be efficient, and the best skilled for the project at hand.


Having the right hands on the job makes a difference. When we see companies say things like "a century of collective experience," we all look around and laugh. We can count pretty high, but not high enough to tally the years of experience we have in supplying job sites of every size with skilled and well trained Journeyman and Apprentices.