Multi-foundation radon systems

A standard sub-slab system works because the gravel and soil under a single poured slab are connected — depressurize one point and the whole slab follows. But when a home has a basement and a crawlspace, or an addition poured years later on its own footing, those areas are physically separated underground. Pull a vacuum on one and the other is untouched.

The fix is a diagnosis-first approach: a mitigator maps the foundation, identifies each isolated zone, and designs the system accordingly — sometimes multiple suction points tied to one fan, sometimes a slab system plus a sealed crawlspace membrane, occasionally two independent systems. Skipping this step is the most common reason a “mitigated” home still tests high.

Cost depends on how many zones your home has and how they’re accessed, so these jobs are quoted after a look at the foundation rather than off a flat rate. Every system still ends with a post-install re-test — on a multi-foundation home that confirmation matters even more, because it proves every zone actually dropped below the 4 pCi/L action level.

Not sure how your home is built? Start with the mitigation overview or test first, and we’ll sort out the right system when we quote it.