Who are we?

The Master Insulators’ Association of Ontario is an accredited bargaining agency with the Ontario Labour Relations Board representing the Unionized Mechanical Insulation Contractors working in Ontario.

Founded in 1942, the MIAO is a not-for-profit organization working towards the advancement and betterment of the Heat & Frost Insulation Industry while promoting the highest standards of safety, workmanship and ethical business practices.

As well as the Unionized Mechanical Insulation Contractors of Ontario, members of the MIAO include the Manufacturers and Suppliers of materials used in Commerical and Industrial insulation systems.

Learn More

How to join

Learn More                         How to join


In this section, you will find a sortable list of the Mechanical Insulation Contractors who are Active Members of the MIAO as well a list of our Associate Members. The MIAO Board of Directors is also listed. 

MIAO Committees

MIAO Affiliates

MIAO Board of Directors

Members’ Lounge

This section is password protected and for use by MIAO Active and Associate Members only.

Log In

Request a Password

Log In             Request a Password

Our new website and the associated content is continuously improving and updating over the course of time, and will be modified with new content and features on a regular basis.

Print Friendly, PDF & Email