Does Concrete Block Radiation?

When it comes to radioprotective materials, rarely is it the case that they block out 100% of all forms of radiation. Most often, they block some amount of certain types, depending on a number of factors. Concrete is no exception: this manmade material has definite radioprotective properties under certain circumstances.

In this guide, we will take a closer look at concrete as a protective material against radiation. We’ll look at how it’s made and what types of radiation it is effective against.

How is concrete made?

To make concrete, a few different ingredients must be added together. Powdered cement, asphalt, or another powdered base is taken and mixed with a blend of rocks and gravel called aggregate. To make it into a spreadable paste, water is added to the mix, turning it into a slurry state that is ideal for pouring.

Concrete can be poured onto roads and other surfaces, into molds, or made into building materials. Once poured, the concrete slurry must be allowed to rest and set in order to dry. Because concrete is poured and then molded, it can be found in various thicknesses — something that is important when it comes to attenuating, or reducing, radiation.

Does concrete block radiation?

To answer that question fully, you first must have an understanding of the different types of radiation. There are two main categories to know: ionizing and non-ionizing. We’ll dive into the basics of each here, but if you want to learn about either in greater detail check out The Difference Between Ionizing and Non-Ionizing Radiation.

Ionizing radiation

Ionizing radiation has a lot of energy — enough to knock an atom’s electrons out of orbit. It travels in tightly wound waves that can be stopped by dense materials. Within the ionizing category, we have several different subtypes, including x-rays, beta waves, and gamma rays. Ultraviolet light also falls under this type of radiation. At large doses, ionizing radiation can cause serious health issues such as cancer and radiation poisoning.

Our bodies are exposed to small amounts of ionizing radiation every day in the form of cosmic background radiation and medical testing. Even an airplane flight can slightly increase your ionizing radiation exposure. Blocking it really only becomes necessary at higher doses — during an x-ray, for example, your doctor may have you wear a lead vest. Lead is effective against ionizing radiation because it is a very dense metal.

So while you probably don’t need to worry about protecting your house from ionizing radiation, it’s worth pointing out that concrete certainly can be effective against this type of radiation, provided it was poured densely enough. If your community has fallout shelters left over from the Cold War, for example, you may notice that these places tend to be made of thick concrete blocks. That is because the concrete would help shield the building’s inhabitants from incoming radiation after a nuclear bomb.

Non-ionizing radiation

On the other side of the spectrum (literally, on the electromagnetic spectrum) we have non-ionizing radiation. This type of radiation has much less energy than its ionizing counterpart, and certainly not enough to knock an electron out of orbit. Nonetheless, non-ionizing radiation has been tied to a host of serious conditions including gliomas and other forms of cancer, as well as male infertility and neurological issues.

Non-ionizing radiation includes microwaves, radio frequency (RF) waves, and extremely low frequency (ELF) waves, as well as infrared light. We more commonly refer to these types of non-ionizing radiation as electromagnetic field (or EMF) radiation. We are constantly surrounded by EMF radiation, from cell towers, cell phones, WiFi signals, power lines, cars, and more. And while the overall dosage from any one device may not be alarming, our cumulative exposure levels can add up to be problematic for our health.

Because EMF waves are so wide, they can penetrate through thicker materials than ionizing radiation. Conductive materials, on the other hand, are generally pretty effective against EMFs. Usually, when you look at EMF blocking products, they are made of copper, aluminum, or another lightweight and inexpensive conductive metal.

That being said, it is still possible for a material to be so thick that the EMF radiation cannot penetrate through. And because concrete can be poured at various thicknesses, it is certainly possible to pour concrete thick enough to attenuate EMF radiation. If the concrete is reinforced with steel rebar, this attenuation can be even greater as the metal makes the concrete even denser.

Now, concrete may be effective, but it is not all that commonly used for this purpose outside of construction. You wouldn’t, for example, want to use a concrete smart meter cover, for a multitude of reasons — it would be heavy, no signal could pass through, it would be difficult to install, etc. If you are building a new construction you could consider concrete walls to help block outside radiation, but even then regular walls with a couple of layers of EMF-resistant paint could be just as effective.

If you are building a new home and are curious to learn about using concrete as a building material, Insulating Concrete Forms Construction may be worth checking out. The book dives into greater detail about insulating concrete forms and gives an idea of what to consider when building a concrete home.

When going the concrete route, keep in mind that you would need the concrete used in construction to be quite thick. When the National Institute of Standards and Technology performed its testing of concrete as a shielding material, it did so using blocks that were eight-inches thick. Also, note that concrete is most effective against higher frequencies, so your concrete walls are going to be better at protecting against RF-EMFs than ELF-EMF radiation.

Testing concrete

If you did want to test the effectiveness of a concrete structure at blocking out EMF radiation, this could be done using an EMF meter. As we mentioned, concrete is more effective against higher frequencies, so make sure your meter is capable of detecting RF-EMF radiation. We like to recommend TriField’s TF2 because it can pick up RFs in addition to electric and magnetic fields. It’s also known for its accuracy. We talk about the TF2 in greater detail in our guide to EMF meters.

To test your structure, take your EMF meter and turn it on while outside of the building. Walk around the full perimeter if possible, noting the EMF levels in different areas. Next, step inside the building and repeat your readings, again taking note of the levels.

Now, in an ideal world, this process would be done before anything is inside the structure, including electricity. Any potential source of EMF radiation inside the concrete structure could skew your results, so be mindful of that as you take your readings. If the concrete is effective and the readings are taken in the right environment, however, it should be apparent that the levels are much lower inside the structure than outside of it.

Protecting against EMF radiation

Outside of new home construction, concrete isn’t really a practical radiation blocking material. For better options, see What Materials Block Radiation. Using radioprotective materials, you can create a number of DIY items to keep you and your family safe from EMF radiation.

It is worth noting that protecting against EMF radiation doesn’t mean eliminating all exposure. That is simply not a realistic goal in today’s world for everyone, although living off-grid does work for some. For others, however, cell phones, cars, and electronics are an unavoidable fact of life. And in those instances, the best you can hope for is to reduce the amount of EMF radiation you are exposed to on a daily basis.

This can be achieved in a few ways. Switching to a wired internet connection and getting rid of WiFi, for example, can dramatically reduce your home’s EMF levels. Other steps to take include switching to incandescent light bulbs, installing a smart meter cover, using protective paint in spots around the home, and using a wired headset when talking on your phone. Reducing EMF exposure in the bedroom is particularly important, as well, and things like bed canopies and protective blankets can help reduce exposure while sleeping.

You can’t control all sources of EMF radiation, so reducing your exposure is really about influencing those things that you can control. You can’t help if there is a nearby power line or cell phone tower, but you can keep dangerous levels of smart meter radiation from reaching your bedroom. Easier said than done, but try not to worry too much about the aspects you can’t control and focus on the ones you can.

For those interested in learning what else they can do to protect against EMF radiation, our guide to Whole House Protection is a fairly comprehensive resource to look over.

Final thoughts

Concrete can indeed block various forms of radiation, depending on its thickness. It is most useful in this way as a building material in the construction of new homes and developments. When it comes to EMF radiation, however, conductive materials such as copper and certain types of stainless steel are a better bet for most projects around the home.