Construction Work Area Depressurization

Danilo, I believe depressurization can be achieved by exhausting the areas that generate a high amount of construction dust, for example, wood or drywall cutting from the cleaner areas. Containing these construction areas by temporarily hanging plastic and then exhausting them would create a negative pressure. When developing the IAQ plan the contractor has to incorporate all the recommended SMACNA guidelines that are applicable to the project. The guidelines are intended to maintain good indoor air quality during construction. In order to prevent circulation of contaminated air, project teams need to either install temporary barriers or exhaust the area to create a pressure difference. It really depends on the type of construction activity that takes place. The project team can decide what is more applicable to their project. 

The strategy for Pathway Interruption is left to the discretion of the project team. I don't believe depressurization is mandatory and if project teams feel that temporary barriers are sufficient for the type of construction activity that takes place at their site, then that should be fine.  With regards to Clean Areas, they are either occupied areas or areas that are free from construction debris.  Hope that helps.