13 Building Materials That Block EMF

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Building Materials That Block EMF

Today, EMFs are all around us, but which materials effectively block EMFs? It’s crucial to know which products can help you create a safer environment for your home or business.

Building materials that block EMF are:

  1. Concrete
  2. Reinforced concrete
  3. Cinder blocks
  4. Metal shielding fabrics
  5. Bricks
  6. EMF paint
  7. EMF wall shields
  8. Wood
  9. Aluminum
  10. Galvanized steel
  11. Copper
  12. Silver
  13. Stainless Steel

All the materials guard against EMF, but some are more effective than others.

You’ve probably noticed that electronic systems and devices are increasingly more abundant in everyday life. Cellphones, routers, microwaves, laptops, power lines, and cell towers are familiar producers of an electromagnetic field.

You may have recently added another source of EMFs like a smart speaker or smart TV to your collection. The influence and scope of EMFs are hard to escape, but there are ways to limit the field’s effect on your health and well-being.

Which Ordinary Materials Block EMF?

Although there are many new advances in EMF blocking techniques, several ordinary materials are also useful in blocking EMF. Completely Blocking EMF is not possible, but the following materials offer higher degrees of protection than other building materials.


Solid concrete is a common substance that contractors often use for the construction of a residential and commercial property. Concrete is not a common substance for constructing homes, but as more people become aware of EMF effects, concrete’s use as a residential material became more accepted and available.

The National Institute of Standards and Technology (NIST) conducted several tests on various materials to rate their ability to block EMF. The purpose of the tests was not related to public health but was performed to benefit contractors who wanted to minimize EMF interference from Wi-Fi and other electrical sources.

The scientists tested solid concrete, without reinforcement from rebar, and found that thicker concrete was more effective in blocking EMF. Here is a sample of the chart showing the NIST findings on concrete.

Concrete500 MHz8 GHz
4″ thick7-1122-23
8” thick17-2558-73
12″ thick31-4587-96

The numbers in the table represent decibels. 20 dB= 99% shielding, 40dB= 99.99% shielding. Therefore, 4″ concrete shields less than half as much EMF as 12″ concrete.

While 4″ concrete is ineffective at shielding EMF at 500MHz or 1 GHz, 8″ and 12″ concrete have over a 99% shielding rate at the same frequencies. The tests conclude that the thicker the concrete, the more effective it is in shielding EMF.

Reinforced Concrete

Concrete reinforced with two standard sizes of rebar did not improve the material’s shielding capabilities, and in some tests, the reinforced concrete was less effective in blocking EMF.

Concrete500 MHz8GHz
Solid Concrete (No Rebar)2373
140mm Rebar with Concrete2368
70mm Rebar with Concrete2671

The reinforced concrete with 70mm rebar offers slightly more protection form EMFs at 5 GHz, but at 8 GHz, the solid concrete tested higher than the 70mm rebar.

If you’re only planning on using concrete to shield EMFs, it’s wise to use solid concrete since reinforced concrete offers few advantages. However, depending on the structure you’re building, you may have to install reinforced concrete according to the building codes in your area.

Cinder Blocks

The NIST tested cinder blocks without adding concrete or any other material to the blocks’ hollow spaces. The scientists performed tests using one to three cinder blocks. Each block was 8″ thick.

Cinder Blocks500 MHz8 GHz

The cinder blocks proved less effective at blocking EMF than concrete, but some speculated that the cinder blocks’ ability to shield could be improved by filling the hollow sections with concrete.


The most common material for all construction projects is lumber. Since over 90% of residential properties are constructed with wood, it’s essential to examine how EMF saturation affects the ordinary American household.

The NIST test for wood used common types of lumber available in the United States. Fir, spruce, and pine were tested at various thicknesses. However, the authors suggest that oak lumber, due to its density, may offer more protection than other types of wood.

Wood500 MHz8 GHz

Wood is not a useful material for blocking EMFs unless it is exceptionally thick. The 6″ lumber was the only type that prevented close to 99% of EMFs. However, using more than six inches of lumber for home construction is not feasible due to space constraints in most building projects.

The suggestion that oak logs could offer more protection is reasonable but impractical. Few contractors would be willing to build a home using large logs of oak, and most building codes and covenants would prohibit the use of logs in residential or commercial construction.

Does Brick Block EMF?

Another common material for constructing homes and commercial properties is brick. The tests used one to three bricks, and the results show that bricks were less effective in blocking EMFs at a lower frequency.

Bricks500 MHz8 GHz
One brick016
Two bricks3.514
Three bricks427

Although using three bricks resulted in a 99% shielding rate at 8 GHz, the three bricks only shielding a fraction of EMFs at the lowest frequency (500 MHz). Therefore, bricks are not efficient materials for shielding low-frequency EMFs.

Which Recently Developed Products Block EMF?

Although most homes and businesses are constructed with wood, brick, or concrete, some contractors use more advanced building materials to shield EMFs.

Until recently, most high-end blocking materials were not available to the average contractor. Government contractors use advanced methods to shield offices from outside EMF influence. This practice is not intended to ensure the safety of government employees, but it’s more of a security concern.

Sensitive data and passwords can be exposed to outside infiltration if a building does not include EMF shielding. Also, rooms, where heads of state communicate on secure lines, are designed with several layers of protection.

Although there is conflicting data concerning the dangers of EMFs, more contractors and homeowners are increasingly using advanced methods to block EMFs.

Unlike conventional building materials, new forms of EMF shields are expensive and are not familiar to all contractors.

The Role of Metals in EMF Shielding

Does Metal Attract EMF

Because of their high levels of conductivity, metals are an ideal choice for blocking EMFs. Read my article on how metals block EMF. Here are commonly used metals in the burgeoning market of EMF protection.

  • Aluminum
  • Galvanized steel
  • Copper
  • Silver
  • Stainless Steel

Metals can also be combined with other metals or materials to offer added EMF protection. Here are examples of metal combinations.

  • Silver-plated nickel
  • Nickel-coated carbon
  • Silver-plated aluminum
  • Silver-plated glass
  • Silver-plated copper
  • Passivated aluminum

Metal shielding is a cost-effective choice for reducing EMF transmissions, and it does not require a contractor to install.

Silver EMF Shield

The silver EMF shield is a transparent material made from a nylon fabric embedded with silver. Also, it’s less expensive than other fabrics and materials, and it’s challenging to handle. It’s fragile and prone to staining.

The shield is more effective when it’s not frequently moved and is suitable for screens, curtains, and canopies. It shields against low and high-frequency EMFs, and its protection ranges from 30 MHz to 18 GHz.

Ripstop Silver Shield

One form of shielding that has been receiving a lot of attention and praise is the ripstop silver shield. Unlike the silver EMF shield, the ripstop shield is much easier to use. Rather than being composed of delicate, transparent fabric, ripstop is more like a giant silver blanket.

Ripstop shields were first used in medical applications. The fabric has antibacterial properties that repel odors and benefit the healing process. Recently the ripstop shields were re-engineered and improved to perform electromagnetic shielding.

The material is composed of a ripstop nylon fabric embedded with pure silver. The shields are incredibly versatile. They’re simple to cut with a pair of household scissors, and you can attach them to a variety of surfaces. Here some of the most popular ways to use the ripstop shield.

  • Shielding from Wi-Fi routers
  • Shielding from electric fields
  • Window drapes
  • Shielding from microwaves
  • Garment liners
  • Shielding from static electricity
  • Faraday cages

Unlike other shields that cannot be cleaned or have complicated cleaning instructions, ripstop silver can be washed by hand and is safe when installed in close proximity to your skin.

Swiss Daylite EMR Shield

The Swiss daylite EMR shield is a transparent, extremely lightweight fabric. It is composed of a polyester fabric embedded with a combination of copper and silver. Its primary use is to shield against the low-frequency EMFs from cellphone towers and Wi-Fi routers.

The daylite shield cannot be washed by hand, but it can be cleaned in a domestic washer. However, you should only use a non-bleach detergent and should avoid using the tumble-dry setting on your dryer.

You can install the shield in canopies, curtains, and room dividers.

High-Performance Silver Mesh

The high-performance silver mesh is an expensive fabric commonly used for mobile phone shields, medical uses, drapes, garments, electronic components, and tents. The mesh has a shielding range of 30 MHz to 3 GHz and is rated to be effective at temperatures from -22° F to 194° F.

EMF Shielding Netting HNG80

The EMF Shielding Netting is composed of tightly knit polyester fibers and is designed for floors, ceilings, and walls. It is commonly used where information security is a top priority.

Government offices and saferooms, corporate offices, and foreign embassies rely on the netting to guard against hackers using low and high-frequency methods to penetrate defenses.

The costly material is an effective way to block EMFs but is not readily available to domestic consumers.

Cotton Grid Fabric

One of the least expensive ways to guard against EMFs is cotton grid fabric. It is made of cotton embedded with pure silver. Like cotton made for garments, grid fabrics are incredibly simple to work with and install.

You can wash the fabric by hand, and it’s not difficult to cut or manipulate. One of the most significant advantages the fabric has over other materials is its anti-static properties. If any charged object encounters the fabric, the cotton grid immediately discharges the object.

The grid fabric also offers superior protection against radio frequencies. Any radio frequently transmitting in proximity to the cotton grid is abruptly blocked.

Manufacturers use the fabric to make drapes, clothing, and bedding.

Magnetic Field Shielding Film

Magnetic field shielding is an ideal choice for homeowners looking for an economical way to protect against low and high-frequency EMFs. It comes in a large roll that is easy to cut with scissors and is simple to install.

The roll is made of a copper and nickel embedded polyester fabric. It is a sturdy material that will not corrode when installed in extreme environmental conditions such as high humidity. It is perfect for covering ceilings, walls, and floors.

Its longevity is superior to other forms of blocking materials because its effectiveness is not diminished when it’s moved or lightly damaged. If you’d like to try out a magnetic shielding film, click here.

Silverell Fabric

Silvrell is composed of rayon fabric embedded with silver. It’s exceptionally soft and pliable and is more suitable for the manufacturing of bedding and garments.

Stainless Steel Mesh

For protecting windows from EMFs, stainless steel mesh is an ideal material. You can install the mesh on the inside and outside of windows to provide excellent shielding for low and high-frequency intrusions.

The mesh is constructed with close-knit grids of surgical steel. Like magnetic field shielding, it’s resistant to corrosion and can be installed in humid conditions.

Window Film Shielding

If you don’t like the way stainless steel mesh looks on your windows, you can try using a window film shielding. EMFs will completely penetrate an untreated glass pane, and many people forget to shield their windows when considering how to protect their homes.

If your windows are already treated with a heat-reducing additive or have a tinted UV blocker, do not use film shielding. The EMF shielding will protect your windows from low and high frequencies if installed over existing films, but the new shield will decrease the previous film’s effectiveness and longevity.

The film will shield your windows from EMFs, but it’s not cheap. If you’re interested in purchasing a roll of EMF blocking film, click here.

EMF Paint

A practical way to protect your home or business, without changing the look or structure of a room, is to use EMF paint. Rather than cutting and piecing together pieces of fabric, you can apply EMF paint as a primer to your walls and ceilings.

Apply the paint on thick for superior protection from EMFs and use the latex paint of your choice to finish the job. Most EMF paints, like this one, specify a 99.995% shielding rate against EMF. The level of protection is exceptional, but it comes at a cost. The paints cost close to $90/liter, and if you apply two layers for the maximum shielding effect, you may spend over $300.

EMF Wall Shields

Installing an EMF wall shield protects you against electric fields and radio frequencies. You can use the wall shields to cover walls, ceilings, electrical panels, and cables.

Installing the wall shields involves applying an adhesive to the surface, cutting the material to size, covering the surface with the shield, and protecting the seams of the shield with aluminum tape.

What is a Faraday Cage?

A Faraday cage, named after the scientist Michael Faraday, is a structure that shield’s its interior from static and non-static electromagnetic fields. It’s an old concept that was first demonstrated by Faraday in the Nineteenth century.

Recently, the Faraday cage’s most common application is with device protection. EMF Pouches for your phone, tablet, or sensitive data cards are made of ripstop silver lining or silver mesh. Similar card-sized Faraday shields protect your credit card’s chip from a hacker’s probing software.

What is a Building Biology Consultant?

If you want to find out what level of EMF is present in your home, you can hire a building biology consultant. The consultant takes EMF readings from different areas of your home and checks your routers, devices, and appliances for EMF output.

After meticulously inspecting your house for several hours, the consultant offers recommendations on how to fix or improve your EMF problems. The inspection is lengthy because the consultant checks other environmental concerns unrelated to EMF concerns.

The inspectors examine your detergents, cleaners, plumbing fixtures, air filters, and flooring. You can hire a consultant if you want to see how EMFs affect your home in absolute terms, but a home inspection can cost close to $400. If you want to save money, you can purchase an EMF meter, like this one, for around $50.

How Can You Reduce EMFs Without Shielding?

Although scientific tests have not definitively proved that EMFs contribute to sickness or cellular damage, most scientists agree that avoiding prolonged exposure to EMF’s is a wise decision.

Most also contend EMFs are more harmful in close proximity. If you distance yourself from devices or systems producing EMF’s, you stand a higher chance of avoiding any unpleasant effects.

The EMFs from nearby mobile towers or radio stations may not be as concerning as the mobile device you keep close to your brain daily. Several doctors recommend using an earpiece with a mobile device and securing your Wi-Fi devices in Faraday pouches.

Reducing EMF in Your Home

With Wi-Fi devices and mobile towers becoming more numerous every year, you may wonder how to avoid the EMFs they emit. Depending on the scope of your problem and your budget, there are several options available from simple solutions to complex construction projects.

Whatever your situation is, rest assured, you can quickly reduce your exposure to EMFs and focus on more concrete issues in life that don’t involve invisible fields.