Simply put ventilation is the act of moving air, exhaust the hot air and intake the cool. Every time stale, overheated air in your home or attic is vented out and fresh air is pulled in to replace it, you have what is known as an "air exchange."
We replace all flashing and counter flashing on the roof as needed with 90 degree non corrosive metal. As previously discussed, all penetrations are covered in rubber before any flashing is installed ensuring a watertight seal. Special attention is always taken regarding proper sealing of all chimneys and existing skylights as these are common areas that leak. A saddle will get constructed behind a chimney or in any other problematic area when needed. soil and plumbing stacks are all rebooted using a dedicated flashing kit and a top of the line neoprene seal.