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Perlite & perlite insulation: this article illustrates and describes perlite materials used for perlite insulation, sound insulation, soil mix, and other applications. Perlite photographs in this article are by the author or were provided courtesy of Redco and their website about perlite insulation.
Description of Non-asbestos perlite materials sometimes mistaken for asbestos in buildings.
This article series assists building buyers, owners or inspectors who need to identify non-asbestos-containing insulation materials as well as asbestos-containing materials (or probable-asbestos) in buildings by simple
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Perlite & Perlite
Perlite, including perlite building Insulation is a non-fibrous non-asbestos-containing material which has an R-value of about 2.7 per inch and would not be expected to contain asbestos.
Perlite is a type of rock (a form of volcanic glass) which is mined, crushed, heated and thus expanded (4 to 20 x original volume) to form an inorganic insulating material.
Water trapped in the rock causes it to expand. Perlite insulating material is produced in granular forms from coarse to a fine powder which weighs about two pounds per cubic foot. Photo at above left courtesy of Redco .
Perlite is used for the insulation of low-temperature application equipment such as cryogenic (-100 degC or -150 degF) and super-cold storage tanks and test chambers.
Perlite insulation is also used in food processing applications (up to 4 degC or 40 degF - about the minimum food refrigeration temperature).
Our photo ( above left) sows what coarse perlite looks like when added to a planting soil mix.
Expanded perlite (from our potting soil sample) is easily examined under the stereo microscope (photo at below-left) to show the mechanical properties of the material.
Perlite building insulation is produced in a granular or even a powder form, but by some manufacturers it is formed into an insulating board (by combining perlite with gypsum, for example for use under building roofs).
Perlite insulation materials are resistant to mold, rot, and rodents.
Perlite also resists moisture uptake, making it useful for use in areas exposed to water or dampness such as in floor leveling compounds and under-floor insulation where it may also be used for noise control (as a sound-deadening material, possibly between building floors).
Perlite as an under-floor insulation and as an acoustical insulator is described by the Schundler Company.
Perlite insulation density and weight
Perlite insulating products are produced in a range of densities (weight per cubic foot) from two pounds per cubic foot to fifteen pounds per foot.
Expanded perlite (from our potting soil sample) has been washed in alcohol and photographed again in the stereo microscope (at left).
Perlite has a typical density of 3-4 pounds per cubic foot in building insulation products, and is described by various industry sources as inexpensive and dimensionally stable (doesn't shrink) and non-combustible.
Perlite as a non-fibrous, non-asbestos green building material
That perlite is a non-fibrous material is quite apparent in our forensic lab photo at 600x. The sample was prepared in alcohol and washed to remove most potting soil fragments from the source product we used for this examination.
Some writers name perlite insulation products as a "green building material", probably because it is a natural, mined resource (not considering the energy costs of mining and production), and more, because perlite is used as a concrete additive to make insulating and light-weight concrete, or as an insulating material to fill the cores of masonry block constructed walls.
Perlite insulation may also be used to insulate masonry wall cavities (between brick courses in a structural brick wall) or in a building interior to fill the cavity between a masonry exterior wall and the interior finish-wall furring strips and drywall.
More information about perlite insulation is available from Redco II, a perlite insulation manufacturer in North Hollywood, an industry source for this insulating material.
Redco II sells perlite for horticultural purposes (those white particles you see in some brands of potting soil), for industrial and construction applications such as an additive in the formation of concrete, and for general industrial uses including as a filtering medium.
Perlite is applicable in various processes. Starting from LPG, LNG, natural gas tank insulation in factories to Filtration in food and chemical industries. Filler additive material in paints to Horticulture product in Plants and agriculture application and many more.
Construction & Insulation Applications of Perlite
The use of perlite offers many functional and long-term economics advantages to the construction industry. Among the major applications are as a aggregate in lightweight concrete and plasters, as a loose fill insulation product to fill cavities of masonry brick walls, as an ingredient in the manufacture of insulation boards, bricks and tiles.
Thermal Insulation Properties of Perlite
The glassy closed cellular structure gives perlite a very low thermal conductivity, combined with the lightweight and low combustibility making it the ideal material for thermal insulation. Insulation of rooftops with perlite concrete to reduce heat gain into the building is a popular application.
Perlite in Lightweight Floors
The low density of perlite concrete makes it ideal for filling of floors and sunken areas where weight of concrete is to be reduced.
Perlite for Sound Insulation
The large irregular surface area of Perlite Particles make them a useful ingredient in sound absorbing material designed for acoustical treatment to prevent reflection and reverberation of sound from ceiling and upper wall areas. Perlite is also a principle ingredient in acoustical plasters and tiles manufacture.
Perlite for Cryogenic Insulation
Perlite displays a low thermal conductivity through a wide range of temperatures, pressure and densities. This attribute makes it the ideal insulation material for cryogenic products storage even as low as -268 deg.C. Its fine particle size combined with the inert nature and free flowing nature makes filling and removal an easy task.Apart from being used for insulation of big cryogenic tanks, like LNG, Oxygen, Ethylene and Nitrogen.
It is also used to insulate air-separation plants, vacuum and non-vacuum small tanks and small tanks and small cold and hot storage containers like flasks.
Perlite Uses in Horticulture
The capacity of perlite to adsorb water, improve aeration and provide proper drainage makes it an excellent product for horticulture application. Since perlite is inorganic sterile, chemically inert with a neutral pH, the lightweight insulating properties which reduces extremely the soil temperature fluctuations makes perlite use as a unique growing medium and soil conditioner.
Perlite insulation products find wide application in plant propagation, cultivation of crops, domestic gardening, stadium turf lawn conditioning, seed propagation, tissue culture hardening, nurseries, green house growing and landscaping.
Industrial Applications of Perlite & Filtering Aids
Perlite functions as a filter aid to facilitate easy separation of the liquid from the solid particles in industrial filtration by improving flow rate of filtrate and also achieving the required clarity. Perlite does not interfere chemically with the slurry and impart no taste, colour or odour to the filtrate product and this quality has extended its use in the food and beverage industries. Other applications include, pharmaceuticals, chemicals, water, paints and resins, oils, sugar, beer, wine and industrial coatings.
Perlite used in Refractories
Perlite is used as a lightweight, low iron content ingredient in insulating castables used in petrochemical, sponge iron and cement plants.It is also used in refractory bricks that find application of back up insulating layers in boilers, industrial furnaces etc.
The fine particle size, high brightness, lightweight, chemically inertness and milding abrasiveness make perlite an excellent filler material.It is used as filler in paints, resins, coatings, synthetic rubber, polishes, cultured marble etc.
Fine perlite aggregate with a blend of non-ionic surface-active agents can be used as a safe hand and industrial cleanser in work spots like project site where water is scarce. Grease and oils from soiled hands can easily b ....
Perlite Insulation R-Values
Reader Question: relationship between particle size and perlite insulation R-values
(Sept 16, 2014) Jim Tolbert RiverRidge_WI@yahoo.com said:
What is the relationship between expanded perlite particle size and R=factor for high temp (chimney) insulation? That is, is coarse, medium, or fine particles have a higher R factor and what particle sizes are in each of the classifications? Many thanx!
Jim here is some research on the effects of particle size on Perlite insulation R-values. It is apparent that smaller particles are likely to yield higher R-values. But you'll want to be careful to consider more than just particle size. The amount of moisture in perlite can have a significant effect on its insulating and heat retaining properties.
Beikircher, Thomas, and Matthias Demharter. "Heat Transport in Evacuated Perlite Powders for Super-Insulated Long-Term Storages up to 300 C." Journal of heat transfer 135, no. 5 (2013): 051301.
Fesmire, J. E., and S. D. Augustynowicz. "Thermal Performance Testing of Glass Microspheres Under Cryogenic Vacuum Conditions." Advances in Cryogenic Engineering; Volume 49 A 710 (2003): 612-618.
Jamei, M., H. Guiras, Y. Chtourou, A. Kallel, E. Romero, and I. Georgopoulos. "Water retention properties of perlite as a material with crushable soft particles." Engineering Geology 122, no. 3 (2011): 261-271.
Ochs, F., W. Heidemann, and H. Müller-Steinhagen. "Effective thermal conductivity of moistened insulation materials as a function of temperature." International Journal of Heat and Mass Transfer 51, no. 3 (2008): 539-552.
Papadopoulos, A. M. "State of the art in thermal insulation materials and aims for future developments." Energy and Buildings 37, no. 1 (2005): 77-86.
Sarı, Ahmet, Ali Karaipekli, and Cemil Alkan. "Preparation, characterization and thermal properties of lauric acid/expanded perlite as novel form-stable composite phase change material." Chemical Engineering Journal 155, no. 3 (2009): 899-904.
Sengul, Ozkan, Senem Azizi, Filiz Karaosmanoglu, and Mehmet Ali Tasdemir. "Effect of expanded perlite on the mechanical properties and thermal conductivity of lightweight concrete." Energy and Buildings 43, no. 2 (2011): 671-676.
Vaou, V., and D. Panias. "Thermal insulating foamy geopolymers from perlite." Minerals Engineering 23, no. 14 (2010): 1146-1151.
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(June 21, 2011) Vikramaditya Mathur said:
Is it mineral rockwool based products or perlite that will rule the future market. Rockwool is skin irritating on contact whereas perlite products are relatively more brittle and tend to break in transit. Both are very eco friendly energy efficient insulators and a different class from chemical polymeric foam which has a relatively hazardous and carcinogenic process and ingredients. With high price of petroleum based raw materials and possibilities to use more affordable natural gas in countries like India, rockwool is a strong contendor! Lets see what the future holds.
(Mar 20, 2014) mag said:
I'm planning to build a house, in my country suppliers are offering Perlite bricks for construction, whats gonna be your suggestions should i use ordinary cement brick and then perlite insulation, or go directly with perlite brick? what are pros and cons...
thanks in advance
Interesting question, Mag.
I don't have the exact data for your product (and am researching it) but in general, perlite-laced masonry units have a higher R-value than conventional masonry but much lower than actual insulation, be it foam or fiberglass.
For example, the Masonry Advisory Council lists 6" masonry block 59% solid as R 1.25 vs 6" block FILLED WITH Perlite having R 3.95 - but compare these with solid foam insulating board (styrofoam or other insulating materials) that have a much higher R per inch.
You don't give your climate or heating/cooling loads; the choice of how and where insulation should be installed and how much are affected by that information.
Search InspectApedia for "Table of Insulation Material R-Values & Other Materials' Insulating Properties " to read the data you should consider.
10 22 2014 frank hocker said:
is it possible to use perlite as a blown in insulation and if it is. how would I do it?
I'd ask a perlite manufacturer, though I suspect it's a bit fragile for that application. About using blown-in perlite in general, texts describe using layer of perlite insulating board between layers of other insulating materials to obtain higher R-values: see Graves, Ronald S., and Robert R. Zarr, eds. Insulation Materials, Testing and Applications, 3rd Volume. Vol. 3. ASTM International, 1997. from whom we quote this excerpt:
The 2:1 PCM/perlite mixture and the 6:1 PCM/perlite mixture, both on a weight ... or in perlite insulation board and placed between layers of batts or blown-in ...
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 Perlite Institute is an industry association formed in 1949 to promote the use of perlite insulation materials and to conduct research about perlite. The Perlite institute offers a 2002 article confirming that Perlite does not contain asbestos. A separate study supported by the Perlite institute (also published in 2002) concludes that perlite is a safe product, citing studies establishing that it is not a significant respiratory hazard to workers (Cooper 1975-76, Weill, Tulane Univ., 1994, and other studies). The institute also cites that for some workers exposure to perlite (presumably perlite dust) can result in temporary physical irritation, discomfort, impaired visibility, and enhancement of accident potential.
 Redco II, North Hollywood CA 818-759-2255 maintains Perlite.Net an information website about perlite insulation.
 Schundler Company, Edison, NJ 732-287-2244 provides information about the application-use of both perlite and vermiculite insulation products.
 Asbestos: How to find and recognize asbestos in buildings - visual inspection methods, list of common asbestos-containing materials
 Fiberglass: Indoor Air Quality Investigations: Health Concerns About Airborne Fiberglass: Fiberglass in Indoor Air from HVAC ducts, and Building Insulation
 Enviro-Scare: Electric Power Lines, Electromagnetic Fields, Cancer Risk, & "Enviro-Scare" - The Normal Curve Cycle of Public Fear of Environmental Issues
 Dust from the World Trade Center collapse following the 9/11/01 attack: the lower floors of this building contained spray-on fire-proofing asbestos materials.
 Asbestos Information Links: Asbestos Detection, Testing, Recognition, Hazards, Field Photos, and Information Sources, including
health-related links such as legal services and information about mesothelioma and other cancers.
 Asbestos Identification, Walter C.McCrone, McCrone Research Institute, Chicago, IL.1987 ISBN 0-904962-11-3. Dr. McCrone literally "wrote the book" on asbestos identification procedures which formed
the basis for current work by asbestos identification laboratories.
 Stanton, .F., et al., National Bureau of Standards Special Publication 506: 143-151
Asbestos products and their history and use in various building materials such as asphalt and vinyl flooring includes discussion which draws on ASBESTOS, ITS INDUSTRIAL APPLICATIONS, ROSATO 1959, D.V. Rosato, engineering consultant, Newton, MA, Reinhold Publishing, 1959 Library of Congress Catalog Card No.: 59-12535 (out of print).
Asbestos Identification and Testing References
Asbestos Identification, Walter C.McCrone, McCrone Research Institute, Chicago, IL.1987 ISBN 0-904962-11-3. Dr. McCrone literally "wrote the book" on asbestos identification procedures which formed
the basis for current work by asbestos identification laboratories.
Stanton, .F., et al., National Bureau of Standards Special Publication 506: 143-151
Pott, F., Staub-Reinhalf Luft 38, 486-490 (1978) cited by McCrone
ASHRAE resource on dew point and wall condensation - see the ASHRAE Fundamentals Handbook, available in many libraries. The following three ASHRAE Handbooks are also available at the InspectAPedia bookstore in the third page of our Insulate-Ventilate section:
2005 ASHRAE Handbook : Fundamentals: Inch-Pound Edition (2005 ASHRAE HANDBOOK : Fundamentals : I-P Edition) (Hardcover), Thomas H. Kuehn (Contributor), R. J. Couvillion (Contributor), John W. Coleman (Contributor), Narasipur Suryanarayana (Contributor), Zahid Ayub (Contributor), Robert Parsons (Author), ISBN-10: 1931862702 or ISBN-13: 978-1931862707
2004 ASHRAE Handbook : Heating, Ventilating, and Air-Conditioning: Systems and Equipment : Inch-Pound Edition (2004 ASHRAE Handbook : HVAC Systems and Equipment : I-P Edition) (Hardcover)
by American Society of Heating, ISBN-10: 1931862478 or ISBN-13: 978-1931862479
"2004 ASHRAE Handbook - HVAC Systems and Equipment The 2004 ASHRAE HandbookHVAC Systems and Equipment discusses various common systems and the equipment (components or assemblies) that comprise them, and describes features and differences. This information helps system designers and operators in selecting and using equipment. Major sections include Air-Conditioning and Heating Systems (chapters on system analysis and selection, air distribution, in-room terminal systems, centralized and decentralized systems, heat pumps, panel heating and cooling, cogeneration and engine-driven systems, heat recovery, steam and hydronic systems, district systems, small forced-air systems, infrared radiant heating, and water heating); Air-Handling Equipment (chapters on duct construction, air distribution, fans, coils, evaporative air-coolers, humidifiers, mechanical and desiccant dehumidification, air cleaners, industrial gas cleaning and air pollution control); Heating Equipment (chapters on automatic fuel-burning equipment, boilers, furnaces, in-space heaters, chimneys and flue vent systems, unit heaters, makeup air units, radiators, and solar equipment); General Components (chapters on compressors, condensers, cooling towers, liquid coolers, liquid-chilling systems, centrifugal pumps, motors and drives, pipes and fittings, valves, heat exchangers, and energy recovery equipment); and Unitary Equipment (chapters on air conditioners and heat pumps, room air conditioners and packaged terminal equipment, and a new chapter on mechanical dehumidifiers and heat pipes)."
1996 Ashrae Handbook Heating, Ventilating, and Air-Conditioning Systems and Equipment: Inch-Pound Edition (Hardcover), ISBN-10: 1883413346 or ISBN-13: 978-1883413347 ,
"The 1996 HVAC Systems and Equipment Handbook is the result of ASHRAE's continuing effort to update, expand and reorganize the Handbook Series. Over a third of the book has been revised and augmented with new chapters on hydronic heating and cooling systems design; fans; unit ventilator; unit heaters; and makeup air units. Extensive changes have been added to chapters on panel heating and cooling; cogeneration systems and engine and turbine drives; applied heat pump and heat recovery systems; humidifiers; desiccant dehumidification and pressure drying equipment, air-heating coils; chimney, gas vent, fireplace systems; cooling towers; centrifugal pumps; and air-to-air energy recovery. Separate I-P and SI editions."
Building Research Council, BRC, nee Small Homes Council, SHC, School of Architecture, University of Illinois at Urbana-Champaign, brc.arch.uiuc.edu. "The Small Homes Council (our original name) was organized in 1944 during the war at the request of the President of the University of Illinois to consider the role of the university in meeting the demand for housing in the United States. Soldiers would be coming home after the war and would be needing good low-cost housing. ... In 1993, the Council became part of the School of Architecture, and since then has been known as the School of Architecture-Building Research Council. ... The Council's researchers answered many critical questions that would affect the quality of the nation's housing stock.
How could homes be designed and built more efficiently?
What kinds of construction and production techniques worked well and which did not?
How did people use different kinds of spaces in their homes?
What roles did community planning, zoning, and interior design play in how neighborhoods worked
Energy Savers: Whole House Systems Approach to Energy Efficient Home Design [copy on file as /interiors/Whole_House_Energy_Efficiency_DOE.pdf ] - U.S. Department of Energy
"Energy Savers: Whole-House Supply Ventilation Systems [copy on file as /interiors/Energy_Savers_Whole-House_Supply_Vent.pdf ] - ", U.S. Department of Energy energysavers.gov/your_home/insulation_airsealing/index.cfm/mytopic=11880?print
"Energy Savers: Whole-House Exhaust Ventilation Systems [copy on file as /interiors/Energy_Savers_Whole-House_Exhaust.pdf ] - ", U.S. Department of Energy energysavers.gov/your_home/insulation_airsealing/index.cfm/mytopic=11870
"Energy Savers: Ventilation [copy on file as /interiors/Energy_Savers_Ventilation.pdf ] - ", U.S. Department of Energy
"Energy Savers: Natural Ventilation [copy on file as /interiors/Energy_Savers_Natural_Ventilation.pdf ] - ", U.S. Department of Energy
"Energy Savers: Energy Recovery Ventilation Systems [copy on file as /interiors/Energy_Savers_Energy_Recovery_Venting.pdf ] - ", U.S. Department of Energy energysavers.gov/your_home/insulation_airsealing/index.cfm/mytopic=11900
"Energy Savers: Detecting Air Leaks [copy on file as /interiors/Energy_Savers_Detect_Air_Leaks.pdf ] - ", U.S. Department of Energy
"Energy Savers: Air Sealing [copy on file as /interiors/Energy_Savers_Air_Sealing_1.pdf ] - ", U.S. Department of Energy
Fiberglass: Indoor Air Quality Investigations: Health Concerns About Airborne Fiberglass: Fiberglass in Indoor Air from HVAC ducts, and Building Insulation
Humidity: What indoor humidity should we maintain in order to avoid a mold problem?
Ice Dam Leaks in building attics and roof cavities, how to inspect for evidence of leaks, identify causes, and correct bad attic ventilation, improper roof venting, and these causes of attic mold or roof structure damage
The National Institute of Standards and Technology, NIST (nee National Bureau of Standards NBS) is a US government agency - see www.nist.gov
"A Parametric Study of Wall Moisture Contents Using a Revised Variable Indoor Relative Humidity Version of the "Moist" Transient Heat and Moisture Transfer Model [copy on file as/interiors/MOIST_Model_NIST_b95074.pdf ] - ", George Tsongas, Doug Burch, Carolyn Roos, Malcom Cunningham; this paper describes software and the prediction of wall moisture contents. - PDF Document from NIS
Pergo AB, division of Perstorp AB, is a Swedish manufacturer or modern laminate flooring products. Information about the U.S. company can be found at http://www.pergo.com where we obtained historical data used in our discussion of the age of flooring materials in buildings.
Piquet Wall Construction: See this photo of
piquet wall construction - involving timber-framed wall construction with long top girts, diagonal timber bracing, and small diameter logs
placed vertically along with concrete chinking to fill in the wall plane.
Plank House Construction: weblog from plankhouse.wordpress.com/2009/01/25/plank-house-construction/ and where plank houses were built by native Americans, see
Large 1:6 Scale Plank House Construction / P8094228,
Photographer: Mike Meuser
06/12/2007 documented at yurokplankhouse.com where scale model Museum quality Yurok Plank Houses are being sold to raise money for the Blue Creek - Ah Pah Traditional Yurok Village project.
Re-Bath, tub lining products is a bath tub relining manufacturer and distributor located in Tempe, Arizona - see rebath.com
Rubblestone Wall Filler: See this Lartigue House using exterior-exposed rubblestone filler between vertical timbers of a post and beam-framed Canadian building.
"Weather-Resistive Barriers [copy on file as /interiors/Weather_Resistant_Barriers_DOE.pdf ] - ", how to select and install housewrap and other types of weather resistive barriers, U.S. DOE
Carson, Dunlop & Associates Ltd., 120 Carlton Street Suite 407, Toronto ON M5A 4K2. Tel: (416) 964-9415 1-800-268-7070 Email: email@example.com. The firm provides professional home inspection services & home inspection education & publications. Alan Carson is a past president of ASHI, the American Society of Home Inspectors. Thanks to Alan Carson and Bob Dunlop, for permission for InspectAPedia to use text excerpts from The Home Reference Book & illustrations from The Illustrated Home. Carson Dunlop Associates' provides extensive home inspection education and report writing material.
The Illustrated Home illustrates construction details and building components, a reference for owners & inspectors. Special Offer: For a 5% discount on any number of copies of the Illustrated Home purchased as a single order Enter INSPECTAILL in the order payment page "Promo/Redemption" space.
TECHNICAL REFERENCE GUIDE to manufacturer's model and serial number information for heating and cooling equipment, useful for determining the age of heating boilers, furnaces, water heaters is provided by Carson Dunlop, Associates, Toronto - Carson Dunlop Weldon & Associates Special Offer: Carson Dunlop Associates offers InspectAPedia readers in the U.S.A. a 5% discount on any number of copies of the Technical Reference Guide purchased as a single order. Just enter INSPECTATRG in the order payment page "Promo/Redemption" space.
The Home Reference Book - the Encyclopedia of Homes, Carson Dunlop & Associates, Toronto, Ontario, 25th Ed., 2012, is a bound volume of more than 450 illustrated pages that assist home inspectors and home owners in the inspection and detection of problems on buildings. The text is intended as a reference guide to help building owners operate and maintain their home effectively. Field inspection worksheets are included at the back of the volume.
Special Offer: For a 10% discount on any number of copies of the Home Reference Book purchased as a single order. Enter INSPECTAHRB in the order payment page "Promo/Redemption" space. InspectAPedia.com editor Daniel Friedman is a contributing author.
Special Offer: Carson Dunlop Associates offers InspectAPedia readers in the U.S.A. a 5% discount on these courses: Enter INSPECTAHITP in the order payment page "Promo/Redemption" space. InspectAPedia.com editor Daniel Friedman is a contributing author.
The Horizon Software System manages business operations,scheduling, & inspection report writing using Carson Dunlop's knowledge base & color images. The Horizon system runs on always-available cloud-based software for office computers, laptops, tablets, iPad, Android, & other smartphones