Radon Mitigation & Soil Gas Control
NBC 9.13.4 Compliant Radon Reduction Systems
Radon mitigation in Toronto costs $1,500–$4,000 for a sub-slab depressurization system, reducing radon gas levels below Health Canada's guideline of 200 Bq/m³ — essential in areas with granite bedrock.
⚠️ Health Canada Radon Warning
Radon Facts
- • #2 cause of lung cancer after smoking
- • 16% of lung cancer deaths from radon
- • 7% of Canadian homes exceed 200 Bq/m³
- • Cannot be detected without testing
Action Levels
NBC 9.13.4 Soil Gas Control Requirements
Article 9.13.4.2 - Air Barrier Systems
- ✓ 6 mil polyethylene below slab
- ✓ Sealed at all penetrations
- ✓ 150mm overlap at joints
- ✓ Sealed to foundation walls
- ✓ Protect during construction
Article 9.13.4.3 - Sub-Slab Depressurization
- ✓ 100mm granular layer required
- ✓ 3" PVC extraction pipe
- ✓ Rough-in to roof level
- ✓ Future fan capability
- ✓ Electrical outlet provision
Sub-Slab Depressurization System Components
Collection
Perforated pipe in granular layer collects soil gas
Extraction
Inline fan creates negative pressure under slab
Discharge
Vent pipe exhausts gas above roof line
Complete Radon Mitigation Services
Radon Testing
- • Long-term (3+ month) testing
- • Short-term (2-7 day) testing
- • Digital continuous monitors
- • Health Canada approved methods
- • Detailed report & recommendations
Starting at $150
Active Mitigation
- • Sub-slab depressurization
- • Inline radon fan installation
- • Pressure field extension
- • System monitoring gauges
- • Post-mitigation testing
$2,700 - $4,900
Passive Systems
- • New construction rough-in
- • Vent pipe installation
- • Granular gas permeable layer
- • Vapor barrier installation
- • Future activation ready
$850 - $1,600
Sealing & Barriers
- • Foundation crack sealing
- • Sump pit covers
- • Floor drain traps
- • Penetration sealing
- • Vapor barrier repairs
$550 - $2,200
Crawlspace Solutions
- • Membrane depressurization
- • Encapsulation systems
- • Ventilation improvements
- • Vapor barrier installation
- • Access hatch sealing
$2,200 - $5,400
Monitoring & Maintenance
- • Annual system inspections
- • Fan performance testing
- • Continuous monitoring setup
- • Filter replacements
- • System optimization
$200 - $550/year
Professional Installation Process
Initial Testing & Assessment
Comprehensive radon testing to determine levels and identify entry points. Building assessment for optimal system design.
System Design
Custom mitigation plan based on home construction, foundation type, and radon levels. NBC 9.13.4 compliance verification.
Core Drilling & Excavation
Precision core drilling through slab. Excavate collection pit below slab. Install perforated collection pipe.
Piping Installation
Install 3" PVC vent pipe from collection point to exterior. Route through interior walls or exterior mounted.
Fan & Electrical
Install inline radon fan in attic or exterior. Connect dedicated electrical circuit. Install system monitor and alarms.
Sealing & Testing
Seal all cracks and openings. Install sump covers and drain traps. Post-mitigation testing to verify effectiveness.
NBC Concrete Requirements for Radon Control
📋 NBC 9.3.1 Concrete Specifications
Compressive Strength Requirements
| Application | Min. Strength |
|---|---|
| Walls, Columns, Footings | 15 MPa |
| Interior Floors | 20 MPa |
| Garage/Carport Floors | 32 MPa |
| Exterior Steps | 32 MPa |
Water/Cement Ratios
| Application | Max W/C |
|---|---|
| Walls, Columns, Footings | 0.70 |
| Interior Floors | 0.65 |
| Garage/Carport Floors | 0.45 |
| Exterior Steps | 0.45 |
❄️ Cold Weather Requirements (Air Temp < 5°C)
- • Concrete temp: 10-25°C during mixing
- • Maintain ≥10°C for 72 hours after placing
- • No frozen materials in mix
- • Protected curing required
- • Garage floors: 5-8% air entrainment
- • Exterior steps: 5-8% air entrainment
Aggregate Specs
- • Max: 1/5 form width
- • Max: 1/3 slab thickness
- • Well-graded, no organics
Curing Standards
- • 7 days minimum moist cure
- • 28-day strength testing
- • No load before full cure
Quality Control
- • Slump testing on-site
- • CSA A23.1 compliance
- • No site water addition
Site-Batched Concrete Mix (NBC Table 9.3.1.7): Standard mix ratio 1:2:3 (cement:sand:gravel) with controlled water content. Ready-mix concrete must meet CSA A23.1 standards for materials and methods.
Reference: National Building Code of Canada 2015, Part 9, Section 9.3.1 - Concrete
All concrete work meets or exceeds NBC requirements for structural integrity and durability.
Why Choose Dryspace for Radon Mitigation
C-NRPP Certified
Canadian National Radon Proficiency Program certified professionals
Guaranteed Results
We guarantee radon levels below 200 Bq/m³ or your money back
Complete Solutions
From testing to mitigation to ongoing monitoring
NBC Compliant
Full compliance with NBC 9.13.4 soil gas control requirements
Radon Mitigation FAQs
How long does radon mitigation installation take?
Most residential systems are installed in 1-2 days. Complex systems or multiple suction points may require additional time.
Will the system be noisy?
Modern radon fans operate at 50-60 decibels (similar to a bathroom fan). We install fans in optimal locations to minimize noise.
What are the operating costs?
Typical systems use 50-90 watts, costing $50-100 per year in electricity. Fans typically last 10-15 years.
Can I install a system during construction?
Yes! Passive rough-in systems cost $850-1,500 during construction vs $2,700-4,500 for retrofit active systems.
Is radon only in basements?
Radon is typically highest in basements but can affect all levels. Upper floors usually have 40-50% of basement concentrations.
Do all homes need testing?
Health Canada recommends all homes be tested. Radon levels vary significantly even between adjacent homes.
Related Services & Resources
- → Exterior Waterproofing: Complete exterior protection
- → Interior Waterproofing: Interior drainage systems
- → Foundation Repair: Fix cracks and leaks
- → DELTA-MS Membrane: Premium waterproofing membrane
- → Waterproofing Guide: Complete educational resource
- → Interior vs Exterior Comparison: Which method is right for you
Ready to Protect Your Home?
Get a free inspection and quote from Toronto's most trusted waterproofing experts.