Radon Testing in Portland & SW Washington

Portland Radon Testing.
Know Your Number.

Radon is the second leading cause of lung cancer in the US, behind smoking. It has no smell, no color, and no warning signs. A 48-hour continuous monitor test, following EPA testing protocol, is the only way to get a measured reading of your home's level. Serving Portland, Oregon City, and all of SW Washington.

Schedule Radon Testing → (971) 202-1311
21,000+ US Deaths from Radon Annually
4 pCi/L EPA Action Level
48hr Minimum Test Period
3,000+ Inspections by Russ
Why It Matters

The Health Risk Nobody Warns You About

Radon is a radioactive gas that forms when uranium breaks down in the soil under your home. It seeps up through the foundation and builds up inside, especially in basements and crawlspaces. You can't smell it. You can't see it. And breathing it over time significantly raises your risk of lung cancer.

The EPA and the Surgeon General both call radon the second leading cause of lung cancer in the US. Only smoking kills more. The risk is cumulative. The longer you breathe elevated levels, the higher your lifetime risk. Kids and anyone who spends a lot of time on lower floors get the most exposure.

Every home is different. Regional averages tell you nothing about what is happening under your specific slab. A neighbor can test low while your home reads well above the action level. Testing is the only way to know. Radon testing can be added to any home inspection for one efficient visit.

EPA Guidance on Radon Levels 4 pCi/L or above: EPA recommends mitigation. Between 2 and 4 pCi/L: worth considering, since there is no fully safe level. The national average indoor level is 1.3 pCi/L. Many Portland-area homes test above the action level.

No Safe Level Exists

The EPA says any radon exposure carries some risk. Even homes below 4 pCi/L can benefit from mitigation because the fix is affordable and typically reduces levels.

Any Home Can Have High Levels

New or old, slab or basement, wood frame or concrete. Radon gets in through any crack or gap in the foundation. Construction type doesn't predict risk.

Levels Change Over Time

A test from five years ago isn't reliable today. Soil shifts, renovations, and HVAC changes all affect radon. The EPA recommends retesting every two years if you have a mitigation system, and again after major renovations.

Mitigation Actually Works

A licensed radon mitigation system can reduce indoor levels by up to 99%. Mitigation is a well-established fix, typically done in a single day. An elevated result is a known problem with a known solution.

Portland & SW Washington

What the Data Says About This Region

Clark County, WA sits in EPA Radon Zone 1, the highest of the three zones. Multnomah and Washington Counties are Zone 2, and Clackamas County, which includes Oregon City, is Zone 3. Zone maps predict county averages, though, and averages hide a wide range. Plenty of homes in this region test well above the 4 pCi/L action level.

Zone 1

Clark County, WA

Clark County, WA sits in EPA Radon Zone 1. Multnomah and Washington Counties are Zone 2, and Clackamas County, including Oregon City, is Zone 3. Elevated readings turn up in all of them.

1.3 pCi/L

US Indoor Average

The national average indoor radon level. Homes in this region routinely test above it. Testing is the only way to know where your home stands.

4 pCi/L

Action Level

At or above 4 pCi/L, the EPA recommends a mitigation system. The technology is well understood and installed by licensed contractors all over this region.

Pacific Northwest soil conditions matter. Portland and SW Washington have geology, clay soils, and building practices that can push radon into homes at rates above what the zone averages suggest. I inspect this region every week. Elevated levels show up regularly, including in brand-new homes across Portland, Oregon City, and Clackamas County.
What's Included

Professional Testing. Plain-Language Results.

Every radon test uses a continuous radon monitor placed in the home for a minimum 48-hour test, following EPA testing protocol for real estate transactions. The device records levels every hour for the full test period, which produces a time-stamped data log rather than a single number. Radon levels rise and fall with weather and season, so a 48-hour result reflects conditions during the test, not a guaranteed long-term average.

  • Continuous electronic monitor placed in the lowest livable area
  • 48-hour minimum test period per EPA protocol
  • Tamper-evident, time-stamped hourly data log
  • Results in pCi/L compared against EPA benchmarks
  • Digital report with a plain-English explanation of your results
  • Next-step information included if levels exceed the action threshold
  • Can be bundled with any home inspection for one visit
  • Meets the testing standard used in real estate transactions

Radon Testing Pricing

Add-On with Inspection $150
Standalone Radon Test $225

Adding radon to your home inspection is the most efficient option. One visit, one scheduling window, results within 48 hours of test completion. The standalone price applies when no full inspection is being done at the same time. See full pricing for all inspection options.

Military discount available. Veterans, active duty, reservists, military families, and first responders get 10% off the home inspection fee. The discount applies to the inspection fee, so radon testing is priced the same for everyone. Mention your service when you book.
The Process

How Radon Testing Actually Works

Four steps from booking to results. No guesswork. No waiting by the mailbox.

Step 1
1

Book Online

Schedule any time at trustedhome.org/scheduler. Add radon to your home inspection or book it standalone. Instant confirmation.

Step 2
2

Monitor Placed

Russ places the electronic monitor in the lowest livable area. Closed-house conditions begin. The device starts recording immediately.

Step 3
3

48 Hours of Data

The monitor records radon every hour for the full test period. This produces a time-stamped data log that follows EPA testing protocol.

Step 4
4

Results Delivered

Your digital report arrives with your average pCi/L reading, the full data log, a plain-language explanation, and next steps if levels are elevated.

When to Test

Six Situations Where Radon Testing Matters

Radon testing isn't just for buyers. Here are the six most common situations where getting a professional test makes sense.

Buying a Home

Test before you close. If levels are elevated, you know it before closing, while mitigation is still a decision and not a surprise. After closing, that cost is yours.

Selling a Home

A pre-listing radon test helps reduce surprises. Have low-level results on file for buyers, or fix elevated levels before buyers find them.

Homes with Basements

Basements trap radon at higher levels than the rest of the house. Any home with a basement or below-grade living space should be tested, regardless of age or build type.

Homes You Already Own

The EPA recommends retesting every two years if you have a mitigation system, and again after major renovations affecting the foundation, crawlspace, or ventilation. Many homeowners have never tested at all.

New Construction

Radon-resistant features reduce risk but don't guarantee safe levels. Testing after construction shows how your new home is performing. See new construction inspections.

After Mitigation

Post-mitigation testing shows whether your system is bringing levels down. The EPA recommends a follow-up test no sooner than 24 hours after the system starts running and within 30 days of installation.

DIY vs. Professional

Not All Radon Tests Are Created Equal

Charcoal canister kits exist. So do reasons not to trust them for a real estate transaction. Here's how they compare.

Feature DIY Canister Kit Professional Monitor
Test Method Passive charcoal absorption Continuous electronic recording
Tamper Detection ✗ ✓ Time-stamped log
Accepted in Real Estate Transactions Sometimes ✓ Standard practice
Hourly Data Log ✗ ✓
Results Turnaround 1 to 2 weeks after mailing to lab Within 48 hrs of test completion
Independent Third Party ✗ ✓
Plain-Language Explanation ✗ ✓ With next-step information
If Levels Are Elevated

Elevated Radon Is Fixable.

An elevated result on a house you want is not the end of the road. Mitigation systems are reliable, well understood, and installed all over Portland and SW Washington by licensed contractors. The technology is decades old and typically reduces levels.

The most common method is sub-slab depressurization. A pipe and fan pull radon from below the foundation and vent it outside before it can get in. The system runs quietly and needs almost no maintenance.

If you're under contract, what to do about the reading is a conversation for you and your agent, and the contingency period is when you have it to make. My part is explaining what the number means and what mitigation involves.

If you already own the home, Oregon and Washington both maintain lists of licensed radon mitigation contractors. Mitigation doesn't require moving out and is typically done in a single day.

What Mitigation Looks Like

  • Sub-slab depressurization is the most common method. A pipe and fan pull radon from below the slab and vent it outside.
  • Systems can reduce indoor radon levels by up to 99% and work in virtually any home.
  • Installation is typically done in a single day. No need to leave the home.
  • Post-mitigation testing shows whether your system is bringing levels down.
  • The fix is well understood and the cost usually falls in a known range, which makes it a known quantity rather than an open question.
Typical Mitigation Cost in the Portland Area Typically $800 to $1,500 depending on home size, foundation type, and system complexity. Mitigation is installed by licensed contractors, not by us, so treat this as a general market range and get a quote for your own home. Systems go in across Portland, Oregon City, and SW Washington every week.

Client Stories

What people say about Russ

Real reviews from clients across Portland Metro & SW Washington.

★★★★★ 5.0 Rating35 Google Reviews ★★★★★ 5.0 RatingYelp Reviews
Common Questions

Radon Testing FAQ

Straight answers to what Portland and SW Washington buyers, sellers, and homeowners ask most. Have another question? Call (971) 202-1311. Russ answers his own phone.

View the full FAQ →
The Basics
The monitor stays in place for at least 48 hours, per EPA protocol. For a home purchase, we place the device at the start of the inspection period and pick it up 48 hours later. Results come once retrieval and processing are done. The whole thing fits inside a standard inspection contingency window.
The EPA recommends mitigation for any home at or above 4 pCi/L. Homes between 2 and 4 pCi/L should also consider it, since there is no fully safe level. The national average indoor level is 1.3 pCi/L. See full pricing for add-on rates.
$150 added to a home inspection. $225 as a standalone service. Both use professional electronic monitors and produce a tamper-evident digital report. Adding radon to your inspection is the most efficient and economical option. Full pricing →
Yes, but closed-house conditions must be maintained. Windows and exterior doors stay closed except for normal entry and exit. Your HVAC running normally is fine. The goal is to avoid artificially ventilating the home, which would lower readings and give you inaccurate results.
DIY charcoal kits use passive absorption and must be mailed to a lab. That adds 1 to 2 weeks just for results. They have no tamper detection and aren't always accepted in real estate transactions. A continuous monitor records levels hour by hour, produces a tamper-evident time-stamped log, and follows the EPA testing protocol real estate transactions are built around.
Special Situations
Yes. Many new homes have radon-resistant features, but those features reduce risk rather than guarantee safe levels. Testing is how you check performance. Elevated levels show up regularly in new builds. Don't assume new means safe. Learn more about new construction inspections.
Yes. Russ Motyko holds active licenses in both Oregon (OCHI #1898) and Washington (DOL #1856). We serve Portland and SW Washington, including Clark County communities like Vancouver, Camas, Battle Ground, Ridgefield, and Washougal, plus Oregon City and the surrounding cities.
You can bundle radon with a home inspection and mold testing in one visit. Both are air-quality concerns a visual inspection can't measure. If the home has a crawlspace, basement, or any signs of moisture issues, combining both tests gives you a clearer picture. See pricing for add-on rates.
Results & Next Steps
Elevated radon is fixable. Mitigation systems are well understood and installed by licensed contractors throughout Portland and SW Washington. If you're under contract, what to do about the reading is a conversation for you and your agent, and the contingency period is when you have it to make. I can explain what the number means. The rest is yours to decide.
Oregon's disclosure law requires sellers to disclose known material defects, which can include prior elevated radon results. But if the seller has never tested, there's nothing to disclose. This is exactly why buyers should test independently. A pre-listing inspection with radon testing lets sellers address issues before buyers find them.
The 10% military and first responder discount applies to the home inspection fee, not to add-on services, so radon testing is $150 with an inspection for everyone. Booking radon alongside your inspection is still the cheapest way to get it, and the discount comes off the inspection itself. Mention your service when you book. Military discount details →
Booking & Availability
Usually within 24 to 48 hours. We work 7 days a week and keep the calendar open for buyers under contingency. Same-week bookings are normal. Schedule online →
Portland and the surrounding Oregon cities, plus Clark County, WA, including Vancouver, Camas, Battle Ground, Ridgefield, and Washougal. No travel fee within 40 miles of Oregon City. If you're unsure whether your address is in range, just call.
Yes. You can add radon at the time of booking or by calling before the inspection day. Adding it to a buyer's home inspection is the most efficient option. One visit, one window, and the test runs while you're in your contingency period.

Where We Inspect

Serving Portland Metro & Southwest Washington

Available 7 days a week. No travel fee within 40 miles of Oregon City, and $50 past that. Not sure if we cover your area? Just call.

40 miles, no travel fee
Available 7 days a week
Dual-licensed OR & WA
Oregon state-licensed home inspector seal
Oregon Certified OCHI Lic. #1898
Washington state-licensed home inspector seal
Washington Licensed DOL Lic. #1856

Multnomah County home inspections. Portland and the rest of Multnomah County are full of older housing stock, including 1920s craftsman bungalows in SE Portland, Pearl District lofts, and mid-century homes in NE Portland. Older homes mean knob-and-tube wiring, cast iron drains, and aging foundations. I’ve inspected hundreds of homes across Multnomah County and know what to look for in each neighborhood.

Portland Gresham SE Portland NE Portland NW Portland North Portland Troutdale Bethany Sellwood Pearl District Fairview

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Schedule Today

Get Your Portland Radon Test Scheduled.

48-hour electronic testing. Tamper-evident results. Plain-language report. Available 7 days a week across Portland, Oregon City, and SW Washington. Add it to your inspection or book it standalone.

Schedule Radon Testing → (971) 202-1311

Veteran-owned. Military discount available for active duty, veterans, reservists, and military families. Mention your service when you book.