SSDS basically creates negative pressure under and around the foundation to avoid the movement of vapor from high to low pressure as nature allows. Our system will vent out the gases through the installed pipes to the outside. We will drill a pit through which we can insert the pipes to the subsurface. This will help us reach the gases beneath the slab or the membrane.
Our engineers will then install the pipes as a pathway for the gases. The work becomes much easier in new construction because we can easily incorporate the pipes during construction. Although the placement of SSDS pipes is controversial, we know exactly which location is the most effective. Trust New York Engineers in this endeavor. Our experience speaks volume about our expertise.
Even if there are cracks or holes between the subsurface and the house, vapor will not intrude intensively due to a depressurized environment. However, for quality assurance purposes, our engineers will ensure that such holes are closed up. This shows the importance of site analysis prior to installing the pipes. New York Engineers cares about our work and we ensure that our services are unmatched.
It is not always that we use an active SSDS. In some cases, we might install the passive system in collaboration with the client and after assessing the need. A passive system is applicable in situations where the vapor intrusion is not that intense.
A passive system does not use a fan to create a pressure gradient. Instead, it relies on air currents or a stack effect to let vapor escape from the subsurface. While this may be seen as cost-saving, it is not as effective as the active system, especially in warmer climatic conditions. Ideally, our engineers will still install the pipes in the sub slab to vent out the gas vapors using air currents.
Like we said, it is important to assess the site before recommending any perfect solution for you. If vapor intrusion is not a major concern it may be a waste of costs to install an active SSDS. Our engineers are good in such an assessment. To stay on the safe side, we recommend the active system at all the times despite the cost implications.