Thermablok® Technical Support

Thermablok® Technical Support

Thermablok Physical Properties

Thickness0.32 in (8 mm) TYP
Max. Use Temperature400°F (200°C)
ColorGrey or White
Density9.4 lb/ft3 (0.15 g/cc)
Material Form57 in (1,450 mm) wide     3/8″ X 1.5″ X 4.5′ long
R-ValueR-Value = 10.3 / inch

Thermablok Standards Organization Test Results

Test ProcedurePropertyResults
ASTM C 177Thermal Conductivity via Guarded Hot Plate0.0131 W/m*K @ 10°C
EN 12667Thermal Conductivity via Guarded Hot Plate0.0131 W/m*K @ 10°C
ASTM C 518Thermal Conductivity via Heat Flow Meter0.0148 W/m*K @ 2°C (avg of 3 samples)
ASTM E 84Flame and Smoke SpreadClass A: FSI >5, SDI 20
EN13501-1: 2007Reaction to Fire PerformancePassed Euroclass C-s1,d0
ASTM C 165Compressive Stress / Strain8.0psi @ 10% strain, 30.5 psi @ 25% strain
Specific HeatSpecific Heat1.00 J/g*K @ 40°C
ASTM E 96Water Vapor Transmission Rate1877 ng/Pa*s*m2 (dry cup method)
ASTM E 228Linear Coefficient of Thermal Expansion (@ 10°C)X: 1.06 x 10-5 K-1, y: 1.90 x 10-5K-1
ASTM C 1104Water Vapor SorptionMass Gain = 1.08%

Common Insulators: R-Value/U-Value – Energy of Mfg/CO2 (Environmental Impact)

MaterialR-ValueU-Value* (W/m-K)Energy/MfgCO2/MfgHealth & SafetyEnvironment
Thermablok10.3 USA 1.813 Metric0.01450.04.2No Known Hazards(Occupants/Environment)100% Recyclable(Air/Sand/Poly)
Fiberglass3.8 USA 0.669 Metric0.04039.21.9Some Fiberglass Contains Formaldehyde – Toxic SbO3Recyclable
Polyisocyanurate6.0 USA 1.056 Metric0.02469.85.5Creates Hydrogen Cyanide During a Building FireThermoset – Plastic Not Recycled Petroleum Product
Polystyrene (Expanded) (Extruded)Flame and Smoke Spread0.032116.33.0Contains Mutagens – Suspected Carcinogens – Some add Toxic HBCDPolluting the Oceans Little is Recycled (Breaks down in the Environment creating Vinyl-Benzene) Petroleum Product

Notes: R-value is expressed in ft2•h•°F/Btu. U-value is expressed in W/m-K per standard convention.

    • Thermal conductivity, k, is the property of a material that indicates its ability to conduct heat. It appears primarily in Fourier’s Law
      for heat conduction. Thermal conductivity is measured in watts per kelvin per metre (W•K−1•m−1). Multiplied by a temperature
      difference (in kelvins, K) and an area (in square metres, m2), and divided by a thickness (in metres, m) the thermal conductivity
      predicts the power loss (in watts, W) through a piece of material.
    • Wall assembly R-values are computed and expressed in the U.S. in (ft2•h•°F/Btu). Thermablok U -value expressed using this
      measurement is 0.0971 (BTU-in/ft2•h•°F).
    • Metric U-factors are defined as Watts per square meter per degree Celsius. To convert inch-pound Imperial U-values to metric U-factors,
      multiply by 5.678. To convert metric U-factors to Imperial inch-pound U-factors, divide by 5.678.To convert Imperial inch-pound
      R-values to metric R-values, multiply by 0.1761. One inch = 2.54 cms. One (RSI) U-factor coefficient = 5.678; one R-value = .1761 RSI.
  • USA R Value X 0.176 = Metric R Value

Wall R-Value Losses from Thermal Bridging

Nominal Framing Depth & Spacing“Labeled” Batt Insulation R-Values Between StudsEffective R-Values Batt Installation / Steel StudsWall Thermal Loss R-Value
2″ X4″ @ 16″ CenterR-11
2″ X 4″ @ 24″ CenterR-11
2″ X 6″ @ 16″ CenterR-19
2″ X 6″ @ 24″ CenterR-19

Meeting ASHRAE 90.1-2007 Building Envelope Requirements for U.S. Climate Zones

Climate ZoneNonresidential Requirements All occupancies other than residentialResidential Requirements Spaces in buildings used primarily for living and sleeping.
Residential spaces include, but are not limited to, dwelling units,
hotel/motel guest rooms, dormitories, nursing homes, patient rooms in hospitals,
lodging houses, fraternity/sorority houses, hostels, prisons and fire stations.
1R-13 + 0 ci
U= 0.124
R= 10.6
R-13 + 0 ci
U= 0.124
R= 10.6
2R-13 + 0 ci
U= 0.124
R= 8.06
R-13 + 7.5 ci
U= 0.064
R= 15.63
3R-13 + 3.8 ci
U= 0.084
R= 11.90
R-13 + 7.5 ci
U= 0.064
R= 15.63
4R-13 + 7.5 ci
U= 0.064
R= 15.63
R-13 + 7.5 ci
U= 0.064
R= 15.63
5R-13 + 7.5 ci
U= 0.064
R= 15.63
R-13 + 7.5 ci
U= 0.064
R= 15.63
6R-13 + 7.5 ci
U= 0.064
R= 15.63
R-13 + 7.5 ci
U= 0.064
R= 15.63
7R-13 + 7.5 ci
U= 0.064
R= 15.63
R-13 + 15.6 ci
U= 0.042
R= 23.8
8R-13 + 7.5 ci
U= 0.064
R= 15.63
R-13 + 18.8 ci
U= 0.037
R= 27.0

Basic Thermal Definitions

Thermal conductivity is an intensive property of a material that measures its capacity to sustain heat flow. The units of thermal conductivity are often provided in metric values of Watts/meter-degree Kelvin or W/m-K. The symbol used to denote thermal conductivity is k (or lambda, λ).

  • There are many different unit conversions to Imperial and others:
    • 1 BTU/ft hr F = 1.73 W/m-K or 1730 mW/m-K
    • 12 BTU-in/ft2 hr F = 1 BTU/ft hr F = 1.73 W/m-K
    • 1 BTU-in/ft2 hr F = 0.144 W/m-K or 144 mW/m-K
  • The reciprocal of thermal conductivity is thermal resistivity; an intensive property of a material to resist one-dimensional heat flow.
    Thermal resistivity has units of m-K/W.

    Thermal Resistance (R value)  

    • R is thermal resistance, which is the capacity of a material to impede heat flow over a given area and at a specific temperature.
      The greater the value at a given set of conditions, the better the material will perform as a thermal insulator.
    • The units of thermal resistance are provided in m2-K/W (or ft2 hr °F/BTU).
    • Thickness/k value = R value.
    • Resistances of insulators in series can be added.
    • R-value can be for whole thickness or normalized (e.g. R-value is 12 per in or 24 for 2 inches of R-12 per inch material).
    • R/in = 144/k (in mW/m-K) -> 12 mW/m-K = 12 per inch R value.
    • The reciprocal of thermal resistance is thermal conductance (also known as the heat transfer coefficient), with units of W/m2 K.
      This value is frequently measured in systems as the overall heat transfer coefficient (OHTC).
  • Thermal resistance values are often used in the building and construction markets as a relative measure of thermal insulation
    performance for materials and systems.

   Heat Transfer Coefficient (U Value)  

  • U values measure thermal conductance, a measure of a material or system to permit power flow per unit area      and temperature change (W/m2 K).

U-value is heat transfer coefficient.
Low U values mean good insulation values (very similar to thermal conductivity k).
OHTC -> Overall heat transfer coefficient; frequently used to measure the thermal conductance of systems.
In the world of systems thermal engineering – U value and OHTC are often used synonymously.