Guide to Insulation Terms and Definitions | Koala Insulation

Insulation Glossary of Terms and Definitions | Koala Insulation of the Midsouth

You might not have thought much about insulation as a broad topic, but it’s actually far more complex than most people suspect. This is reflected in the extensive, specialized vocabulary that is used to describe insulation materials, applications, and effects. 

Are you wondering what alligatoring could mean? Or are you feeling baffled by the term “baffles?” Do you need to know what the difference is between C-value and R-value? The insulation experts at Koala Insulation of the Midsouth have the answers! Check out this glossary for the definitions of common insulation-related terms so you can banter about efflorescence and heat transfer with the best of us.

A

A-Component: The primary component of a two-component system. The isocyanate component is used for coating and foam made from polyurethane. Also referred to as A-side.

Abatement: The process of reducing or removing something. For example, noise abatement is a key benefit of having insulation installed because the insulating material muffles sound waves.

Abuse Coverings: Films or jackets that are used to cover insulation, protecting it from abuse or deterioration caused by people and machinery.

Acoustical Treatment: An application of insulation material that has the effect of deadening or muffling the ability of sound to travel past the material.

Air Sealing: The process of sealing cracks, gaps, and holes with caulk or insulation materials to make a building or structure more energy efficient by reducing air infiltration and heat transfer. 

Alligatoring: Crazing or a pattern of cracks in coating or mastic that resembles the texture of alligator skin.

Application Temperature Limits: The temperature range at which adhesives, finishes, and sealants can be applied to a given material without causing any damage to the material from exposure to high or low temperatures.

Attic Rain: A phenomenon caused by inadequate ventilation in a cold attic, in which excess heat and humidity cause condensation to form on the rafters and drip down, flattening insulation and causing other serious water damage issues such as wood rot.

B

Baffles: Small pieces of cardboard or hard plastic that are installed near soffit vents and between roof rafters and soffit vents to prevent insulation from blocking off airflow channels and causing the attic space to suffer damage due to a lack of ventilation. 

Batts: Semi-rigid, thick pieces of insulating material in a rectangular shape, typically composed of fiberglass. They are installed side by side to provide insulating coverage for a surface or cavity and may or may not include a vapor barrier. 

Blanket Insulation: Semi-flexible, flat sheets of insulating material that come in rolls and are unrolled during installation, mainly used to cover large areas with a uniform shape.

Block Insulation: Rigid insulating materials that have been pre-formed into rectangular blocks for installation.

Blown-In Insulation: Loose chunks of cellulose, fiberglass, or other insulating materials that are installed by being "blown in" to a room or space with a blower machine. The clumps fly out of the blower and settle on all available surfaces to create an insulating layer. Since it’s easily disturbed, it’s best used in non-habitable areas of a building, such as a cold attic. 

British Thermal Unit (BTU or Btu): A widely-used unit of measurement that represents the amount of heat that is necessary to raise the temperature of one pound of water by one degree Fahrenheit.

C

C-Value: A measurement of the conductivity of thermal energy that represents the rate of time that it takes for steady-state heat flow through the area of a construction or material unit, induced by a difference in unit temperature between the body surfaces. The lower the C-value is, the more effective the insulating material is.

Caulk: A semi-flexible, watertight polymer sealant, typically made with silicone or vinyl, that is used to seal up gaps, cracks, and holes to prevent water, air, dirt, and more from getting through.

Caulking: The action of applying caulk to a surface or object.

Cold Attic Insulation: The practice of insulating the “floor” of a non-habitable attic space, which is typically not an actual floor but the upper side of the ceiling for the story below, without applying insulation to the walls or rafters of the attic space. This prevents heat from rising into the attic and allows the roof to dry out naturally by venting humidity through the roof and gable vents.

D

Delamination: The process by which a layered material separates into its constituent layers.

Density: The mass of a substance per the substance’s unit volume or its degree of compactness.

E

Economic Thickness: The thickness of a given unit of insulation that provides the optimal exchange of insulating value versus energy cost savings. Increasing the R-value of insulation past the point of economic thickness results in diminishing returns for energy savings.

Efflorescence: A white powdery substance that can appear on the surface of some types of insulation. It is caused by soluble salts surfacing from the insulation.

Energy Star: A program jointly operated by the U.S. Department of Energy (DoE) and the U.S. Environmental Protection Agency (EPA) to rate and certify the energy efficiency of products, materials and structures that meet minimum requirements for energy conservation, such as insulation, appliances and other components or products that resist heat transfer.

Epoxy Resin: Adhesives, sealants, plastics, and other substances or materials that are composed of polymerized epoxides. 

F

Facing: A decorative or protective surface covering insulation.

Fiberglass Insulation: A type of insulation, usually in batt, blanket, or blown-in formats, that is composed of very fine, hair-like strands of glass. It is heat and fire-resistant, making it a popular insulation option for both commercial and residential buildings.

Fire Resistance: The property of an item or material that allows it to endure fire without breaking down and prevent it from spreading to other areas of a building.

Flammable: Objects, gasses, liquids, and materials that are capable of being lit on fire and burning. Inflammable and flammable have the same definition.

Fogging: Condensation droplets or mist that accumulate between panes of glass in an insulated glass unit when the seal along the edge is compromised and the insulating argon gas escapes.

Foil Scrim Kraft (FSK): Vapor retardant insulation facing that is laminated to fiberglass insulation and has a layer of aluminum foil on the exterior side. Also sometimes referred to as FRK.

G

Gable Vents: A louver vent covered by slats and positioned at the top of a roof gable to allow air to circulate through the attic space.

Granular Insulation: A type of insulation made up of small, hollow nodules. The material could be expanded vermiculite, calcium silicate, perlite, diatomaceous earth, cellulose, or microporous insulation. 

H

Heat Flow Rate: The rate at which heat transfer occurs per unit of time in certain types of materials, such as insulation, usually measured in joules per second or watts. The measurement is used to quantify the rate of total heat loss or heat gain in a system.

Heat Gain: When heat transfer occurs from the outside of a structure to the inside due to radiant energy like sunlight.

Heat Loss: The measure of heat transfer from inside a structure to the outdoors through windows, doors, walls, and other building components. It is measured in BTU or kW.

Heat Transfer: The naturally occurring process by which thermal energy attempts to move from a warm place, such as a heated building, to a colder place, such as the outdoors. Insulation prevents heat transfer from taking place or reduces the heat flow rate.

I

Insulating Glass Unit (IGU): A unit composed of two or more sheets of glass separated by a small gap and sealed together at the edges. The gap is filled with argon gas to provide insulation against heat transfer.

Insulation Removal: The task of removing insulation from an entire building or a localized area, typically because it has been destroyed or contaminated by water incursion or vermin.

J

Jacket: 1. A type of facing that is placed over insulation. 2. Flexible foil insulation that is designed to fit around a curved surface, such as a water heater tank.

Joint: The point where two pieces or types of material meet. The joint can be overlapping, sealed or laced together, filled or finished with various materials, such as tape, mastic, additional insulating material, or other options.

K

K-Value: A measurement of thermal conductivity that represents the amount of BTUs of heat that pass through one square foot of any homogeneous substance. 

Knee Walls: Walls of various lengths that support widely-spanning roof rafters and finish an attic space.

L

Lacing: The action of joining insulation materials together or securing them to an anchor point with cords, wires, hooks, and other fasteners.

Loose-Fill Insulation: A format of insulating material that comes in smaller particles or loose clumps. It can be hand-placed, poured, or blown in.

M

Man-Made Vitreous Fibers (MMVF): Non-crystalline, glassy, man-made insulation materials, such as mineral wool or fiberglass.

Mastic: A high-viscosity coating that is applied to insulating materials by hand or with a brush or trowel to act as a sealant and adhesive.

Mineral Wool: A type of insulation that is named for its resemblance to matted wool but is made up of inorganic minerals such as ceramic and rock slag.

Mold and Mildew Resistance: The ability of an object, material, or substance to block the growth of mold or mildew on its surfaces.

N

Net Zero Energy: A structure such as a building that creates the same amount of renewable energy on-site that it requires to operate, resulting in net zero energy consumption.

Noise Reduction Coefficient (NRC):

Non-Flammable: Material or items that can not be set on fire and will not burn. The opposite of flammable or inflammable. 

O

Open Cell Foam: A type of insulating material that is composed mainly of interconnected cellular voids.

P

Patching: The action of restoring or repairing damaged components without removing the entire installation.

Puncture Resistance: The quality or ability of a material to resist being perforated or punctured by sudden impacts or pressure from sharp items.

R

R-Value: A measurement of the thermal performance and effective heat resistance of insulation materials. The approximate R-value is typically expressed per inch of thickness. There are a number of factors that influence the R-value of a given material, such as the density, thickness, and type of the material. The higher the R-value is, the more effective it is at preventing heat transfer. 

Resiliency: The property of a material that determines its ability to return to its original size and shape after being compressed.

S

Score: The act of cutting grooves into insulating material so they can be bent or cracked to fit around an irregular shape or surface.

Spray Foam Insulation: Fibrous or foam insulation materials that are applied to a surface or cavity by spraying it on with a specialized sprayer tool.

T

Tear Strength: The ability of a material to resist being torn apart when pulled from opposite sides at the same time.

Thermal Energy: The energy in a system or object created by the movement of atoms or molecules that determines the system or object’s internal temperature.

U

Unfaced Insulation: Insulating material that does not have a protective facing or vapor barrier.

V

Vermiculite: Insulating material made from naturally occurring vermiculite ore that is expanded to create an exfoliated structure.

W

Warm Attic Insulation: The practice of insulating the walls and floor of the attic space to make a habitable area that can be cooled and heated by the HVAC system in a building. Some types of roof structures are not compatible with a warm attic insulation style because they need air circulating throughout the attic space to remove excess heat and moisture.

Wood Rot: A form of timber decay caused by various types of fungi that eat away at the cellulose or lignin fibers in wood, causing it to soften and crumble apart. Wood rot fungi can only grow on wood that has taken on water and has an elevated moisture content that is above 20% or so.