V18 — specialized system

Radon mitigation and depressurization

Move from a high radon test to an active mitigation strategy accounting for slab, sump, drains, crawlspace and combustion appliances.

Checked: 2026-08-22

VERT / GREEN

Keep long-term test results and foundation/sump layout.

JAUNE / YELLOW

Suction points and fan selection depend on sub-slab communication and the house.

ROUGE / RED

Above the Canadian guideline or designing an active system: use a certified radon mitigation professional.

Triage

Useful tools / data

  • Radon test results
  • Slab/sump/drain plan
  • Ventilation/combustion history

What the professional checks

  • Test sub-slab communication
  • Design suction/exhaust
  • Retest after commissioning
Related path

Continue with the right tools

These links connect this page to the next useful checks and decisions without repeating the full content.

Screen hazardous materialsKnow when to stop and assess asbestos, lead, vermiculite, mould, silica or radon.Open →Track indoor air qualityLog CO₂, radon, PM2.5, humidity and temperature without turning readings into diagnoses.Open →Prepare the emergency sheetDocument controls, equipment, contacts and critical locations in a printable format.Open →Score home resiliencePrioritize water, outages, fire, climate, health and essential records.Open →Sort observed symptomsConnect a visible sign to plausible causes, urgency and the right professional.Open →

Tools related to this issue

Building interfaces to diagnose before enclosure or replacement

These tools connect structure, water, air, frost, wind and mechanical systems so repairs do not hide the cause.

Blind spots before proceeding

V36 checks that can change methods, insurance, testing or work sequence.

Residual V49 interfaces