Radon Guide: What Everyone in Pennsylvania Should Know About Radon Gas in Homes
Liberty Radon Guide

Radon cannot be seen or smelled, but long-term exposure can cause lung cancer and is responsible for more than 20,000 deaths annually. Unfortunately, many Pennsylvania homeowners and business owners are unaware of the dangers of radon. Radon testing is the only way to know if you have dangerous levels of radon gas in your home. This is a comprehensive, easy-to-understand guide about radon gas that every homeowner in Pennsylvania should read.

It's important to know what radon is, how it enters a home, and the health risks to understand why radon testing is necessary and what to do if your home has radon.


What is radon?
How radon enters a home
Where is radon found?
The health risks of radon
Radon in Pennsylvania
How is radon testing performed?
How radon levels are measured
How to reduce radon in your home
Radon reduction systems
How much does radon mitigation cost?
DIY steps to reduce radon in your home
Benefits of using a continuous radon monitoring system
How to find a radon testing and mitigation professional
Questions to ask a pro about radon mitigation in Philadelphia How often is radon testing necessary?
Radon testing in real estate
Radon reduction in new construction homes
Get started with radon testing in Philadelphia today

What is radon?

Radon is an odorless, tasteless, and colorless gas. It is formed when radioactive elements underground, such as uranium, break down and decay over time. Radioactive elements are naturally occurring in rocks and soil, and the radioactive decay process is normal and unavoidable.

When radon escapes from the ground, it is quickly dispersed in the air. Levels of radon gas in outside air are very low, usually only measuring about 0.4 pCi/L (more on understanding these numbers below).

Radon becomes a problem when it enters a home. In an enclosed space, the radon is concentrated and can reach dangerous levels.

How radon enters a home

Radon gas seeps up through the ground and enters buildings through openings in the foundation. While you may think only old, drafty homes, or those with underground basements are susceptible to radon, any building can have high levels of radon.

According to the Environmental Protection Agency, radon can also enter a home through:

  • Cracks in solid floor
  • Construction joints
  • Cracks in walls
  • Gaps in suspended floors
  • Gaps around service pipes
  • Cavities inside walls
  • Water supply

While radon is found all over the United States, some parts of the country have higher levels than others. Do you know what zone your county is in?

Where is radon found?

Radon is everywhere. However, the northern part of the United States tends to have higher levels of radon. According to the EPA, 1 in 15 homes in the U.S. is estimated to have elevated radon levels.

The interactive map from the EPA shows predicted average indoor radon screening levels by county. If your county is in the red zone, it is imperative you do radon testing to determine if you have dangerous levels in your home.

Radon levels can vary in the same home throughout the year, increasing or decreasing due to rain, wind, temperature, and inside factors such as ventilation, new openings in the foundation, and renovations.

The problem with radon is that it poses serious health risks.

The health risks of radon

When you breathe in radon over a long period of time, it can cause lung cancer. According to the American Cancer Society, radon is the second leading cause of lung cancer (behind cigarette smoking), and is the cause of more than 20,000 deaths annually.

Since 2005, a National Health Advisory about the health dangers of radon has been in effect from the office of the U.S. Surgeon General. Since then, the EPA and local governments, acting jointly with radon professionals, have made it a top priority to educate the public about the health dangers of radon.

Radon in Pennsylvania

According to the Pennsylvania Department of Environmental Protection, Radon is a serious issue in Pennsylvania. About 40% of homes in Pennsylvania have dangerous radon levels that require radon mitigation.

The DEP offers a radon test data lookup by zip code that will tell homeowners how many radon tests have been performed in homes in their zip code. The data shows the number of radon tests performed in the basement and first floor, the max result (highest radon level recorded), and average result.

While this is helpful for homeowners, it does not replace radon testing. Radon levels vary significantly - even between neighboring homes.

Like many other states, Pennsylvania offers free radon test kits in certain scenarios. Parents of newborns may request a free test kit to ensure their home is safe. Homeowners who have recently installed a radon reduction system may receive a free long-term testing device to ensure the accuracy of their system. And, in buildings where initial screening levels are over 100 pCi/L, a free short-term confirmation test is available.

Homeowners can call 800-237-2366 or 717-783-3594 to request any of these free kits they qualify for.

Pennsylvania DEP assures homeowners that testing for radon is an easy and affordable process that can give you peace of mind. If your test results show you have unsafe levels of radon, you'll have the information you need to find a professional for radon mitigation in Pennsylvania.

And good news for homeowners looking for a dependable professional: Under the Pennsylvania Radon Certification Act, the DEP regulates a certification program for persons conducting radon gas and radon progeny testing, laboratory analysis and mitigation of radon contamination in buildings. Pursuant to the act, DEP promulgated radon certification regulations in Title 25 of the Pennsylvania Code Chapter 240.

In short, professionals that offer laboratory, testing, and radon mitigation in Pennsylvania must be certified.

How is radon testing performed?

There are several methods of radon testing -- all of them very easy and affordable. Most homeowners start with a DIY radon testing kit to check the levels of radon in their home. If high, the next course of action is to contact a local radon professional for a radon mitigation plan. A mitigation plan includes any steps that are taken to reduce the level of radon in a home.

DIY Radon Testing:

  • Short-term radon testing kits - These are DIY mail-in kits that monitor the radon in your home over the course of 2 to 7 days. They provide fast results, but because radon levels vary throughout the year, they may not be the most accurate. If a short-term test indicates high levels, a long term test - or a radon mitigation plan - is recommended.
  • Long-term radon testing kits - These are DIY mail-in kits that monitor the radon in your home over the course of 90 days to one year. They provide more accurate results since radon levels can change day to day. If the long-term test indicates high levels, radon mitigation is recommended.
  • Continuous radon testing monitors - These are electronic monitors permanently installed in the lowest level of your home that display daily radon levels. They are helpful for monitoring the effectiveness of a radon reduction system.

How radon levels are measured

Radon levels are measured in picocuries per liter of air, or pCi/L for short. A picocurie is the unit of radioactivity equal to 10-12 curies. Don't worry, that doesn't have to make sense to be able to read your radon testing results!

A level of 4 pCi/L is considered high and warrants a radon mitigation plan and reduction system. For homes with radon levels between 2 and 4, you may consider taking steps to reducing your radon levels. If your radon level is below 2, no action is necessary.

Radon Level What You Should Do
Higher than 4 pCi/L Take a second test to make sure the first test results were accurate. You can use another short-term test, or you can use a long-term test.
Contact a licensed professional to install a radon mitigation system if:
-The average of both short-term tests is higher than 4pCi/L, or
-Results from a long-term test are also higher than 4 pCi/L Make sure you retest if you have a radon reduction system installed
Between 2 pCi/L and 4 pCi/L Consider installing a radon reduction system.
If you do this, test for radon again in a few months to see how effective the system is for reducing radon levels.
Lower than 2 pCi/L No action needed. Test your home again if you start living on a lower level (for example, if you turn your basement into a home office or extra bedroom).

If your radon levels are under 4 pCi/L, but you still want to reduce the levels, there are several steps you can take in your home.

How to reduce radon in your home

Radon mitigation is the process of any steps taken to reduce radon in a home. A combination of strategies will produce the best results:

  • DIY steps to seal your home and improve ventilation
  • Professionally installed radon reduction system
  • Continuous monitoring system for peace of mind

Of these, a radon reduction system is the most effective. And, it's easier and more affordable than you might guess

Radon reduction systems

A radon reduction system is professionally installed by a qualified radon contractor. It is a type of ventilation system that physically moves radon out of your home, or out of the soil beneath the foundation of your home.

There are many types of radon reduction systems. A radon contractor will inspect your home, perform diagnostic tests to identify air flow patterns, and consider your home's construction when deciding on the best type of system.

In some cases, your home may benefit from a combination of reduction methods. Some types of radon reduction systems include:

Basement & Slab Homes:

  • Active subslab suction - or subslab depressurization
  • Passive subslab suction
  • Sump-hole suction
  • Block-wall suction

Crawlspace Homes

  • Submembrane suction
  • Active crawlspace depressurization
  • Crawlspace ventilation

While radon reduction may sound like a complex process, it's actually quite affordable considering the safe air and peace of mind your family will have.

How much does radon mitigation cost?

Radon mitigation is inline with other mid-range home repairs. The cost is based on many factors that come down to your home's construction, the radon level, and the combination of reduction methods necessary.

The average cost of a radon mitigation system can be $750 – $1,750, with most homeowners spending about $1,250. Complex reduction systems can cost $2,500 or more.

The most important thing is to work with qualified and experienced radon contractors. Get quotes from three contractors, and make sure to consider everything that's included in the cost -- not just the bottom line.

On page 8 of the EPA's Consumer's Guide to Radon, there is a checklist of what to look for in a radon contractor's quote and contract.

In addition to professional reduction methods, there are DIY steps you can take around your home as well.

DIY steps to reduce radon in your home

Reducing radon levels comes down to properly sealing and ventilating your home.

Steps you can take include:

  • Sealing cracks in foundation, joints and other openings
  • Covering sump pump
  • Covering exposed soil in basements and crawl spaces with plastic
  • Improving ventilation throughout home - radon dissipates in the open air and levels are concentrated when a home is closed up
  • Preventing depressurization - fireplaces and wood stoves can reduce indoor air pressure, which concentrates radon levels
  • Installing a heat recovery ventilator to introduce more outdoor air

Whether you choose to take DIY steps to lower radon levels that are not in the danger zone, or you want to improve the efficiency of a reduction system, a continuous radon monitoring system can provide peace of mind.

Benefits of using a continuous radon monitoring system

A continuous radon monitoring system is often installed as part of a radon reduction system. Also called active radon testing devices, these systems require power to operate around the clock. Usually they provide hourly radon level readings, as well as averages over a certain period. Some will also sound alarms or alert you via a mobile app when radon levels approach dangerous levels. This is helpful as it could mean a part of your reduction system isn't working properly.

Your radon contractor can help you choose an active radon testing device. Or, you can call your state radon office for guidance. Each state radon office can be found on the EPA's interactive map.

How to find a radon testing and mitigation professional

Radon testing and mitigation contractors are in every state to help homeowners reduce radon. There are several ways to find one:

  • Ask friends or neighbors for positive referrals
  • Contact your state radon office; many states offer free or reduced cost DIY radon testing kits and can connect you with a local radon professional for mitigation
  • Find a certified professional from a national organization:

Questions to ask a pro about radon mitigation in Philadelphia

Once you've narrowed down your search, it's important to select the best professional for radon mitigation in Philadelphia. Ask the contractor these questions:

  • Can you provide references for past jobs, including photos and before/after radon test results?
  • Can you explain exactly how the radon reduction system will work, what is involved in the installation process, and how long it will take?
  • Did you inspect my home's structure and prior radon testing results?
  • Do you charge for diagnostics testing?
  • Can you provide proof of Pennsylvania state certification?
  • Can you provide proof of licensure, insurance and bonding?
  • Do you install a warning device in case the system fails?
  • Do you test after installation to ensure efficacy?
  • Do you offer a guarantee to reduce radon levels below 4 pCi/L?

Once you have completed radon testing and implemented any mitigation and reduction strategies, you may wonder how often radon testing is necessary.

How often is radon testing necessary?

The EPA recommends considering these factors to determine the frequency of future radon testing:

  • If you've had high levels in the past and installed a reduction system, a continuous monitoring system is recommended
  • For low/normal levels, retest every 2 years
  • After renovations or remodeling, especially on a lower level (i.e. finishing a basement)
  • If living patterns change (i.e. you start spending more time in the basement)
  • If you're selling your home

If you are selling your home - or buying - be prepared for radon to be a hot topic during the real estate transaction.

Radon testing in real estate

If you're buying or selling a home, it's important to have the home tested for radon and to be informed about any mitigation that has been done. This is especially important in Pennsylvania, where radon levels can be dangerously high.

For buyers:

  • Ask the seller for radon testing results less than 2 years old
  • If the home hasn't been tested, ask the seller to test it
  • If you are building a new home, ask about radon reduction construction strategies and and radon-resistant materials (more on this below)

For sellers:

  • Have radon testing results less than 2 years old
  • If the home hasn't been tested, test it
  • Provide documentation about any radon mitigation that has been done
  • Provide information and warranty on radon reduction system

For real estate professionals:

  • Partner with a local, certified contractor for testing and radon mitigation in Philadelphia
  • Offer professional, short-term radon testing to buyers and sellers prior to the inspection
  • Offer a discount or promotion on continuous radon detectors or radon mitigation services through your partnership

For home inspectors:

  • Include short-term radon testing with professional equipment as part of your standard inspection process
  • Partner with a local, certified contractor for radon mitigation in Philadelphia to give customers quotes as part of the inspection process - if high levels of radon are found

Radon reduction in new construction homes

In Pennsylvania, where radon is a major concern, many contractors and homebuilders choose to use radon-resistant construction methods. While fans and radon reduction systems can be installed after construction, there is no reliable way to test radon levels in the soil before construction begins. Once groundbreaking occurs and construction starts, the best way to mitigate radon is through reduction strategies, including:

  • Installing a radon reduction system and fans, like the ones mentioned above. When a radon reduction fan system is installed during construction, it is built into the home and therefore less intrusive and less expensive.
  • Install a layer of clean gravel, covered with polyethylene sheeting, under the foundation.
  • Install a gas-tight pipe from the gravel layer through the roof to naturally vent radon.
  • Install a junction box for electricity in the attic in the event a more robust radon mitigation system is needed in the future.
  • Thoroughly seal and caulk the foundation.

More good news for homeowners: these radon-resistant construction techniques are already commonplace for many builders, and only cost the builder between $250 and $750 - less than radon mitigation in an existing home. If you're building a new home in Pennsylvania, definitely talk to your builder about radon!

Radon is a dangerous cancer-causing gas, but it is both easy and affordable to test for radon and reduce the levels in your Philadelphia home.

Get started with radon testing in Philadelphia today

Liberty Radon Mitigation in Philadelphia is certified by the Pennsylvania Department of Environmental Protection (DEP).

We help homeowners reduce radon levels with radon mitigation systems, and we offer fair and competitive pricing because we don't think you should overpay for clean air and a healthy home. For added peace of mind, we offer a free radon test post mitigation to ensure your levels are below 4 pCi/L, and all of our radon mitigation systems come with a 7 year warranty. We've installed more than 4,000 radon fans for homeowners throughout Philadelphia, and we're happy to share referrals and test results from past projects.

Contact us at (215) 690-1244 to learn why more homeowners trust Liberty Radon Mitigation in Philadelphia.

If you're a Philadelphia real estate professional or home inspector, contact us to learn more about our partnership programs and how we can help you close more deals with radon testing and mitigation services.