First and foremost ensure that the contractor hired to install the sub-slab depressurization system is certified and has the proper credentials to install the system. Failure to do so can result in an improperly installed system, fines, unsafe work environment, building code violations, and more.
There are a few steps that a certified contractor will take to properly install the sub-slab depressurization system. These steps for the most will remain the same from installation to installation. There may be some variations depending on the environment, building codes, governing body regulations, and a myriad of other as of yet undetermined variables.
- Pilot Test - A sub-slab depressurization system pilot test is first performed.
- Drilling - On the ground floor of a building, a hole is drilled through the floor slab into the soil.
- Vapor Collection - A collection pit, or sub-slab piping, is then created in the area. Extractions fans are mounted next.
- Install Piping - Extracting and venting pipe is then installed.
- Seal - The piping must be sealed where it connects to the floor, as well as around any external venting areas.
- Venting - The vent pipe is then exited through the wall or ceiling of the building.
- Exterior Termination - The piping must terminate above the roofline.
- Monitor - System monitoring gauges, in-line test ports, and floor vacuum test ports are the last items to be installed before the system is complete.
In existing structures, installing an SSD system entails cutting one or more holes in the slab, removing a small quantity of soil from beneath the slab to create a "suction pit," and then placing vertical suction pipes into the holes. These pipes are connected to a manifold containing an exhaust fan, and vapors are in turn vented outdoors. Experience has shown that one or two suction pits are adequate to depressurize typical residential homes. A large commercial building needs more.