Understanding Your Result: When Levels Are "High"
If your test shows elevated radon, understanding what "high" means helps you respond appropriately.
International action levels:
WHO (World Health Organization):
- •Action level: 100 Bq/m³ (2.7 pCi/L)
- •Most protective standard globally
- •Recommended reference point
US EPA:
- •Action level: 148 Bq/m³ (4 pCi/L)
- •Fix your home at or above this level
- •Consider fixing between 74-148 Bq/m³ (2-4 pCi/L)
Canada:
- •Action level: 200 Bq/m³ (5.4 pCi/L)
EU (European Union):
- •Action level: 300 Bq/m³ (8.1 pCi/L)
Key principle: Any radon exposure carries some risk. There is no "safe" level of radon. Even levels below action levels pose some risk and can often be reduced.
Your test result context:
- •Average indoor level: ~48 Bq/m³ (1.3 pCi/L)
- •Average outdoor level: ~15 Bq/m³ (0.4 pCi/L)
- •US Congressional goal: Indoor levels = outdoor levels (not yet achievable in all cases)
- •Practical target: Most homes can be reduced to 74 Bq/m³ (2 pCi/L) or below
If your result is "close" to the action level:
If your average of two short-term tests is near the action level (e.g., 155 Bq/m³ / 4.2 pCi/L), there's about 50% chance your year-round average is somewhat below the action level. However, many homeowners choose to mitigate even at these borderline levels for maximum protection.
Immediate Actions: First 24-48 Hours
When you receive high radon test results, take these immediate steps:
1. Don't panic, but do act
- •High radon is a long-term health risk, not an emergency
- •You have time to make informed decisions
- •Thousands of homes are successfully fixed each year
- •Mitigation is proven and effective
2. Verify the result (if not already done)
- •If only one test done, conduct a second test
- •Use a different test device or location if suspicious
- •Consider professional testing for confidence
- •Follow up short-term test with long-term test if time allows
Exception: If first test is very high (≥ 740 Bq/m³ / 20 pCi/L), don't wait for second test—begin mitigation process immediately.
3. Minimize exposure while planning mitigation
- •Increase ventilation (temporary measure only):
- • - Open windows on lowest level
- • - Run fans to increase air exchange
- • - Note: This is NOT a permanent solution
- •Consider using upper floors more:
- • - Move bedrooms upstairs if radon was high in basement
- • - Reduce time in high-radon areas
- •If extremely high (≥ 1,480 Bq/m³ / 40 pCi/L), consider temporary relocation while mitigation is installed
4. Document everything
- •Save all test results with dates
- •Take photos of test device placement
- •Record radon levels and testing conditions
- •Keep receipts and documentation
- •This helps with mitigation planning and potential home sale
5. Research and prepare
- •Read about mitigation options
- •Understand your home's foundation type
- •Prepare list of questions for contractors
- •Check if permits are required in your area
- •Review financing options if needed
Week 1: Hiring a Qualified Contractor
Selecting the right contractor is the most important decision in fixing your radon problem.
Why hire a professional:
- •Radon reduction requires specialized knowledge
- •Improper installation can increase levels or create new problems
- •Professional systems come with guarantees
- •DIY attempts often fail or cost more in the long run
- •Some regions require licensed professionals
Finding qualified contractors:
1. Check your local/regional radon program
- •Many jurisdictions maintain lists of certified professionals
- •Some regions require licensing or certification
- •Local programs often provide free contractor lists
2. Verify certifications:
- •National radon certification programs
- •Regional certification authorities
- •Professional associations
3. Get multiple estimates (at least 3)
- •Prices can vary significantly
- •Different contractors may propose different solutions
- •More estimates = better understanding of options
- •Competitive bidding may reduce costs
Essential contractor qualifications:
Must have:
- •Current certification or licensing
- •Liability insurance
- •References from recent jobs
- •Knowledge of local building codes
- •Experience with your foundation type
Should provide:
- •Free or low-cost initial inspection
- •Written estimate and proposal
- •Explanation of proposed system
- •Guarantee to reduce levels below specific threshold
- •Timeline for installation
- •Warranty information
Red flags to avoid:
- •No certification or licensing
- •No insurance documentation
- •Unwilling to provide references
- •Pressure for immediate decision
- •Significantly lower price than others (may indicate shortcuts)
- •Vague or incomplete proposals
- •No written guarantee
Comparing Proposals: What to Look For
When evaluating contractor proposals, carefully compare these elements:
1. Proposed mitigation method
- •Sub-slab depressurization (most common)
- •Drain tile suction
- •Sump hole suction
- •Block wall suction
- •Crawl space ventilation or depressurization
Ask: "Why is this method best for my home?"
2. System components
- •PVC vent pipe(s) from beneath foundation
- •Fan to create suction
- •U-tube or other warning device
- •Proper sealing of foundation cracks
- •Electrical connection for fan
Ask: "What specific components are included?"
3. Total cost breakdown
- •Diagnostic testing (if needed)
- •Materials and labor
- •Permit fees
- •Post-installation testing
- •Warranty/guarantee fees
Typical range: $800-2,500 for most homes
- Simple systems: $800-1,200
- Average systems: $1,200-1,800
- Complex systems: $1,800-2,500
- Very complex: $2,500+
Ask: "What does this price include, and what costs might increase it?"
4. Performance guarantee
- •Typical: Reduce to 148 Bq/m³ (4 pCi/L) or below
- •Better: Reduce to 74 Bq/m³ (2 pCi/L) or below
- •Best: Reduce to specific level with adjustment clause
Ask: "What exactly do you guarantee, and what happens if the target isn't met?"
5. Timeline
- •How soon can installation begin?
- •How long will installation take?
- •When will post-installation testing occur?
- •When will you know if system is successful?
Typical: 1-2 days for installation, 1-4 weeks for entire process
6. Aesthetics and noise
- •Where will pipes be routed?
- •Can pipes be hidden or blended?
- •How loud is the fan?
- •Can fan location minimize noise?
Ask: "Show me where pipes will run and where the fan will be mounted."
7. Warranty coverage
- •How long is warranty?
- •What does warranty cover?
- •Is warranty transferable if you sell home?
- •What voids the warranty?
Decision framework:
- •Contractor reputation and experience
- •Guarantee specifics
- •System quality and aesthetics
- •Warranty terms
- •Your comfort level with contractor
Before Installation: Preparation Steps
Prepare your home and family for the mitigation installation:
Homeowner responsibilities:
1. Clear work areas
- •Provide access to basement or crawl space
- •Remove obstacles from work areas
- •Protect valuable items from dust
- •Clear pathway for running pipes
2. Arrange for access
- •Be home or arrange for contractor access
- •Ensure pets are secured
- •Plan for noise and disruption
- •Consider rescheduling if you have infants/vulnerable family members
3. Understand the contract
- •Total cost and payment schedule
- •Work to be performed
- •Timeline for completion
- •Guarantee terms
- •Warranty details
- •What happens if levels aren't reduced
- •Transferability if you sell home
- •Cleanup and damage responsibilities
4. Secure permits (if required)
- •Some jurisdictions require permits for radon mitigation
- •Contractor should handle this, but confirm
- •Ensure work meets local building codes
5. Plan for payment
- •Deposit: 0-50% upfront
- •Balance: Upon completion and successful test
- •Never pay in full before work is done
- •Never pay before post-installation testing confirms success
6. Prepare questions
- •Exactly where will pipes run?
- •Where will fan be located?
- •How loud will system be?
- •What sealing will be done?
- •How long until I can use space normally?
- •What maintenance will be required?
- •What might go wrong?
During and After Installation: What to Expect
Understanding the installation process helps manage expectations:
During installation (typically 1-2 days):
Day 1: System installation
- •Contractor drills hole(s) through foundation
- •May excavate beneath slab or outside
- •Installs suction pipe(s)
- •Mounts fan (usually in attic, garage, or outside)
- •Runs pipes to exhaust above roof line
- •Seals foundation cracks and openings
- •Installs warning device (U-tube or electronic)
- •Connects electrical power
What you'll experience:
- •Noise from drilling and tools
- •Some dust and debris
- •Workers in your home
- •Temporary disruption of affected areas
Day 2: Testing and finishing
- •Cleanup of work areas
- •System testing and adjustment
- •Demonstration of warning device
- •Post-installation radon test placed (to be read later)
Immediately after installation:
What you should receive:
- •Written documentation of work performed
- •Operating instructions for system
- •Maintenance schedule
- •Warning device instructions
- •Post-installation test device
- •Copy of guarantee and warranty
- •Emergency contact information
What system should have:
- •Warning device clearly visible
- •Fan with accessible power connection
- •Labeled switches (don't turn off)
- •Sealed foundation cracks
- •Neat pipe routing
- •Proper exhaust location (away from windows, air intakes)
Post-installation testing (critical!):
- •Test should be placed immediately after installation
- •Leave in place for required duration (usually 48 hours minimum)
- •Keep closed-house conditions during test
- •Send to lab for analysis
- •Should receive results within 1-2 weeks
Success criteria:
- •Radon level reduced to guaranteed level (usually ≤ 148 Bq/m³ / 4 pCi/L)
- •Many systems achieve 74 Bq/m³ (2 pCi/L) or lower
- •Most systems reduce levels by 90-99%
If results don't meet guarantee:
- •Contractor must adjust or modify system at no additional cost
- •May add additional suction points
- •May increase fan power
- •May improve sealing
- •Should retest after adjustments
Don't accept failure: Properly installed systems almost always succeed. If contractor can't meet guarantee, consider getting second opinion.
Living with Your Mitigation System
Once your system is installed and successful, minimal maintenance keeps it working:
Daily/Weekly:
- •Check warning device periodically
- • - U-tube: Liquid levels should be different
- • - Electronic gauge: Should show system operating
- •Listen for fan noise (should be consistent)
- •Note any unusual sounds or changes
Monthly:
- •Visual inspection of warning device
- •Check that fan is running
- •Look for any visible damage to pipes
- •Ensure no new foundation cracks
Every 2-5 years:
- •Replace post-installation radon test
- •Fan may eventually need replacement
- •Typical fan life: 5-10 years
- •Monitor for changes in radon levels
After major home changes:
- •Retest after renovations
- •Retest if you finish basement
- •Retest after foundation work
- •System may need adjustment
Operating costs:
- •Electric fan runs 24/7
- •Typical cost: $50-150 per year
- •Varies by fan size and local electricity rates
- •Small price for protection
Never turn off the system:
- •Fan must run continuously
- •Even brief shutdowns can allow radon to enter
- •If you must shut down, retest when restarted
- •Label switches clearly: "RADON SYSTEM - DO NOT TURN OFF"
When to call contractor:
- •Warning device shows system not working
- •Fan makes unusual noises
- •Fan stops running
- •New cracks appear in foundation
- •Retest shows elevated levels
- •Any damage to system components
Home sale considerations:
- •Mitigation system adds value
- •Provide documentation to buyers
- •Show test results before and after
- •Demonstrate working system
- •Warranty may be transferable
If You Cannot Afford Mitigation
High radon levels require action, but options exist if cost is a barrier:
1. Phased mitigation
- •Some contractors allow payment plans
- •Start with most critical areas
- •Add additional components over time
- •Prioritize sleeping areas
2. Partial solutions
- •Increase ventilation (not as effective but helps)
- •Seal major foundation cracks yourself
- •Use fans to improve air circulation
- •Move sleeping areas to upper floors
- •These don't replace mitigation but reduce exposure
3. Financial assistance
- •Some jurisdictions offer low-interest loans
- •Some utility companies offer weatherization assistance
- •Local housing agencies may have programs
- •Check with regional radon program
- •Non-profit organizations sometimes help
4. DIY with expert guidance
- •Some radon programs offer DIY training
- •Purchase materials, install yourself
- •Have professional test results
- •Not recommended unless you have construction experience
- •Can save money but risks failure
5. Prioritize if selling
- •Fix before listing if possible
- •Disclose radon levels to buyers
- •May affect sale price or feasibility
- •Buyers may require mitigation as sale condition
Important: High radon is serious. If truly cannot afford mitigation:
- •Minimize time in high-radon areas
- •Move bedrooms upstairs
- •Increase ventilation as interim measure
- •Continue seeking resources for proper mitigation
- •Don't ignore the problem—long-term exposure is dangerous
Remember: Most homes can be fixed for cost similar to other common home repairs ($1,200-1,800 typically). This is a worthwhile investment in your family's health.
Related Guides
Source Attribution
This content incorporates material from U.S. Environmental Protection Agency publications, which are in the public domain. Content has been adapted for an international audience with unit conversions, translations to multiple languages, and global framing of concepts while preserving all scientific facts and health guidance.
This content is in the public domain under 17 U.S.C. § 105. Content has been adapted for an international audience and translated to multiple languages while preserving scientific accuracy.