FSK Shield

Class A Insulation-Facing / Vapor Retarder

FSK Shield, Fi-Foil

Fi-Foil's FSK Shield is a single-sided foil facing that is comprised of aluminum foil bonded to natural kraft paper with a flame retardant adhesive and reinforced with tri-directional fiberglass scrim. FSK Shield is intended for use as a class A for >25 FS insulation facing. The product also can be used as an effective vapor retarder.  FSK Shield aluminum facing also reduces radiant heat transfer for added R-value or as a radiant barrier.  FSK Shield is available in 1000 square foot rolls 54" wide.


  • FS 25 Class A Insulation Facing Vapor Retarder Radiant Barrier Added R-value
  • FSK Shield Ceiling Application on Winter Haven High School
  • FSK Shield Reflective Insulation
  • FSK Shield Ceiling Application on Winter Haven High School
  • FS 25 Class A Insulation Facing Vapor Retarder Radiant Barrier Added R-value Easy to Install Replaces Foil Faced Batts
  • FS 25 Class A Insulation Facing Vapor Retarder Radiant Barrier Added R-value
  • FSK Shield Ceiling Application on Winter Haven High School
  • FSK Shield Reflective Insulation
  • FSK Shield Ceiling Application on Winter Haven High School
  • FS 25 Class A Insulation Facing Vapor Retarder Radiant Barrier Added R-value Easy to Install Replaces Foil Faced Batts

Product Key Specs

Width of Roll 54"
Diameter 5"
Lineal Footage 222'
Coverage 1000 sq. ft.
Weight 25 lbs.

Product Test Data

Test Method Description Results
ASTM E-96 Water Vapor Permeance 0.02
ASTM E-84/UL 723 Surface Burning Kraft Exposed Flame Spread Rating 25
Kraft Exposed Smoke Developed Rating 10
Foil Exposed Flame Spread Rating 5
Foil Exposed Smoke Developed Rating 0
FSK Shield & Unfaced Batt Flame Spread Rating 15
Smoke Developed Rating 0
ASTM E-408 Emissivity0.03
ASTM D-828 Tensile Strength (lbs./in) MD:40; XD:25
Scrim pattern per lineal inch MD:2; XD:3
ASTM D-774 Mullen Burst Strength 40 psi
ASTM C-1136 Mold and Mildew Pass
Dimensional Stability percent length change 0.25%
Low Temperature Resistance no crack or delam -40F
High Temperature Resistance no cracking or delam 240F
Puncture Resistance Beach puncture units (Joules) 25
See IAMPO ES Report #0291
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Looking for a Class A / FS 25 Insulation Facing & Vapor Retarder?

Get information about the FSK Shield solution


Compliance and Approvals: 

Meets ASTM E-84

What Our Clients Are Saying

FSK Shield™ Insulation Facing (combined with unfaced batt insulation) is quicker, easier, and costs less than any alternative method for insulating above drop-in ceilings.

Lakeland, FL

Project Profiles

fifoil fsk shield insulation product
Project Information: Project Location: Lake Wales, FLInsulation Contractor: SEMCO Construction, Inc. Bartow, FL 33830


Condensation will occur on any surface when the temperature of the surface is at or below the "dew-point temperature" for an air-water mixture. The dew-point temperature depends on the dry-bulb temperature (measured with an ordinary thermometer) and the relative humidity in the space next to the surface. The dew-point temperature is less than or equal to the dry-bulb temperature. The two temperatures are equal when the relative humidity is 100%. Some examples of dew-point temperature:

As you can see, condensation can occur when the outside temperature is cold. Insulation below a roof deck will have an inside surface temperature that is above the roof surface temperature. The actual temperature of the inside surface depends on the amount of thermal resistance between the roof and the inside surface. The higher the resistance, the closer the interior surface temperature will be to the inside air temperature. Maintaining a reasonable inside relative humidity (less than 60%) is an important factor in preventing condensation.

Heat radiates through the roof, and areas unprotected by the radiant barrier will allow heat to transfer to other areas of the house. Installing a radiant barrier in all areas of the house not only improves overall performance, but also increases comfort levels in unconditioned areas like garages and patios.

Yes, but it is a lot more costly due to labor. The time to consider it is in the new construction phase. There are many other energy upgrades, such as additional blown or batt insulation that can be easily added at a later date if current budget is a factor.

No, they work with or without ventilation but will perform better in ventilated attics. According to the building code, all attics in Florida must be vented.

Extended Version: Studies have shown that with or without a radiant barrier, a ventilated attic is best and the same holds true for a radiant barrier. A house will perform better with a radiant barrier and a ventilated attic than a house with a radiant barrier and a non-ventilated attic. Houses must be designed to meet the building code, which has ventilation requirements with or without a radiant barrier. In both cases, it is the ventilation rate that is important, not the method or type of ventilation.

Radiant barriers reduce heat gain (in the summer) and heat loss (in the winter), so it will benefit both winter and summer savings and comfort. In the summer, heat is reflected back to the outside and in the winter, heat is reflected inwards. 

Various studies including those conducted by the Florida Solar Energy Center have concluded that it would be highly unlikely. In the Sunbelt and specifically Florida, shingles are exposed to roof temperatures of 160 to 190 degrees. Studies have proven that radiant barriers only increase roof temperatures by 2 - 5 degrees. A few degrees more won't make a difference.

To best increase your energy efficiency, you should deal with the problem at its source, the roof, and the best way to address it is by adding a radiant barrier. A radiant barrier is specifically designed for this application and will reduce heat transfer up to 97%. The radiant barrier will improve the performance of both the air conditioning ductwork and the mass insulation and will improve comfort in garages and patios, areas that are typically not conditioned. Studies have shown that the radiant barrier / mass insulation combination out-performs mass insulation alone. Silver Shield Radiant Barrier is installed just below the roof sheathing. The idea is to stop the heat right at the source, the roof, before it gets into the attic or building envelope. Standard mass insulation is almost always installed on the surface of the ceiling, and air conditioning duct systems are almost always installed in the attic space. So without a radiant barrier, the heat would build-up in the attic and reach extreme temperatures, upwards of 140 degrees. Think about it, does it make sense to pump 55-degree air through ducts running through a super-heated attic? And does it make sense to expose insulation to extreme temperatures when the R-value rating is determined at 75 degrees, with the knowledge that the R-value rating drops as the temperature increases? No, of course not! Why let the heat get in the attic in the first place? To summarize, adding a radiant barrier simply provides more benefits over adding more insulation (cooler attic, improvement in duct performance, improvement in ceiling insulation performance, more comfortable areas of the home that are typically not insulated like the garage and patio). If you have extra money in your energy budget, do both; however, the order is radiant barrier first, more ceiling insulation second.

In a home without a radiant barrier at the roofline, your roof radiates solar-generated heat, which elevates attic temperatures upward to 150 degrees or higher. These higher temperatures will increase the heat gain in air conditioning ducts and reduce the performance of mass insulation (the R-values of mass insulation are determined at 75 degrees F - higher temperatures lower the R-value). In addition, the extreme temperatures will saturate the building materials in the attic. This stored heat acts as a heat sink and will continue to transfer heat into the living area of a home even after the sun has set, making the air conditioner run longer and consume more electricity. A radiant barrier stops 97% of radiant heat transfer, which improves the performance of insulating materials and lowers attic temperatures as much as 30 degrees F. A cooler attic will transfer less heat into your air conditioning ducts. Radiant barriers lower both cooling and heating costs, reducing energy expenditures throughout the year.

A radiant barrier is a product that features a low emittance surface(s) (normally aluminum foil) that is designed to significantly reduce heat transfer between a very hot and high radiating surface (bottom of a roof deck) and a cooler highly absorbent surface (i.e. insulation on top of a ceiling). Multiple low emittance surfaces, even multiple layers with enclosed air spaces, can further reduce radiant heat transfer. Effective emittance is one term that can quantify the impact of the impact of the additional surfaces. In summary, the lower the emittance (radiation rate), the better the performance. Radiant barriers have been demonstrated to achieve significant energy savings in a wide variety of building types and in multiple climate zones.


Purchase one of the following products to boost your cell phone signal:

From Verizon Wireless - 3G Newtwork Extender (cost is approximately $249.00).
From AT&T Wireless - 3G MicroCell (cost is approximately $200.00).

Please understand there can be a variety of reasons for a weak cell phone signal, and the products above were recommended by the two top cell phone service providers.

Yes. The ASHRAE Handbook values are a subset of data from the National Bureau of Standards (NBS).

These roofs are excellent reflectors of solar reflectance when new but over-time, as they age and get dirty, the reflectivity is lowered. Radiant barriers would still reduce whatever heat flow that penetrates the roof surfaces by the same percentage - there is just less heat coming through these types of metal roofing materials vs. a shingle roof. As the metal roof ages, and the metal reflects less solar radiation, the radiant barrier has a greater impact on energy savings.

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