how man washrooms are needed on a construction site of 81 workers?

For 81 workers, the number of toilets or washrooms mandated varies depending on the specific regulations and standards being followed.

In Alberta, under the Occupational Health and Safety Code, 5 toilets are required for each sex if there are between 76 and 100 workers of that sex. [5]

Nunavut and Northwest Territories require 5 toilets for 76-100 workers, according to their Occupational Health and Safety Regulations. [4]

In Prince Edward Island, the employer shall provide 5 toilet facilities where there are 75 to 100 persons employed when running water is available. [7]

New Brunswick requires five toilets when the number of employees exceeds 74 but does not exceed 100, if the toilets are chemical, self-contained portable or other similar type. [6]

Ontario Construction Projects Regulation 213/91 states that when water flush toilets or non-recirculating chemical flush toilets are provided, 5 toilets are needed for 61 or more workers [3]

British Columbia requires a sufficient number of readily available flush toilets, or chemical toilets if flush toilets are not practical, at a specified construction site where 25 or more workers will be present at any time. [1] [1]

The Safety Code for the Construction Industry in Quebec stipulates that one toilet is provided per group of 30 workers or fewer. If 25 or more workers are to occupy the site at the same time, a flushing toilet must be placed at their disposal [2] [2]