1. Construction Technical Data
WHAT IS PERLITE?
Perlite is not a trade name but a generic term for naturally occurring siliceous volcanic rock. When
Perlite heated to a suitable point in its softening range, it expands 4 to 20 times its original . This
expansion is due to the presence of 2-6 % of combined water in the core Perlite rock. When quickly
heated to above 8700C the crude rock pops in manner similar to popcorn as the combined water vapor
and creates countless tiny bubbles in the glass – sealed bubbles which account for the excellent
insulating properties and light weight concrete It is classified as chemically inert and has a pH of
approximately 7.
Chemical Composition wt%
Sio2 72 - 75 %
Fe2O3 0.5 - 0.9 %
Al2O3 11 - 14 %
Na2O 2.8 - 4.3 %
K2O 4.8 - 5.7 %
CaO 0.1 - 0.8 %
MgO 0.10 - 0.25 %
H2O ( L.O.1 ) 3.2 - 4.5 %
Physical properties
Color White
Refractive Index 1.5
Free Moisture, Max. 0.5%
PH 6.5-7.5
Specific Gravity 0.32
Bulk Denisty 50-400 kg/m3
Grain Size 0 -5 mm
Softening Point 871-1093 C°
Fusion Point 1260-1343 C°
Specifi Heat 837 J/ kg k
Thermal Conductivity At (24 C°) 0.04 -0.06 W/K.M
Uses of perlite in construction applications:-

2. Because of perlite’s outstanding insulating characteristics and lightweight, it is widely used as a loose-fill
insulation in masonry construction. In this application, free-flowing perlite loose-fill masonry insulation is
poured into the cavities of concrete block where it completely fills all cores, crevices, mortar areas and air
holes. In addition to providing thermal insulation, perlite is also ideal for insulating low temperature and
cryogenic vessels.
When perlite is used as an aggregate in concrete, a lightweight, fire resistance, insulating concrete is
produced that is ideal for roof decks and other applications. Perlite can also be used as an aggregate with
Portland cement and gypsum for exterior applications and for the fire protection of beams and columns.
Other construction applications include under floor insulation, chimney linings, paint texturing, gypsum
boards, ceiling tiles and roof insulation boards .
Construction uses of expanded perlite:-
 Excellent Insulation Material For Insulating External Building Envelop (Roof- Wall – Floor ) .
 Light Weight Concrete, Ranging From About ( 320-640 kg/m3 ).
 Slope To Drain.
 Excellent Fire Ratings.
 Monolithic Roofing Base.
 Insulating f0r Low Temperatures and Cryogenic Gases Storage.
Themeral and mechanical properties of perlite:-
 Perlite gives excellent insulating properties at temperature varying from very low to very high.
For example, perlite is one of the best known insulations for manufacture and storage of liquid
gases such as Oxygen at temperature as low as (-240 oC). At the other extreme, it is effective as
a ladle cover for molten steel to prevent surface cooling when delays in pouring occurred. At high
temperatures begin to soften at about 982 oC, while fusion of the particles at the exposed
surface begins at about 1260 oC. The thermal properties of Perlite are stable for long time and
not effected by environmental changes.
 Perlite gives excellent sound absorbing materials designed for acoustical treatment to prevent
reflection and reverberation of sound from ceilings and upper – Wall areas.
 Perlite loose fill provides efficiently insulating masonry walls. Tests have shown that granular
perlite poured into cores of concrete blocks can reduce heat transmission by 50% and up to 70
% when it is poured into cavity type masonry walls.
 Physical and mechanical properties of Perlite vary according to mix design.
1. LOOSE – FILL MASONRY INSULATION
2. PERLITE CONCRETE INSULATION
3. PERLITE AND SAND LIGHTWEIGHT INSULATING CONCRETE
4. PLASTER
5. PERLITE AS A FIRE RETARDANT

3. 1. LOOSE – FILL MASONRY INSULATION
High heating and cooling costs and the need for energy conservation have resulted in increasing the
awareness of the thermal performance of building envelopes. A Key to perlite's outstanding
performance is the fact that all block cores, voids and mortar are completely field with free flowing
Perlite. With Perlite convective loops within the block is field, thus eliminating convective eating flow
(chimney effect) and subsequent heat losses.
CHARACTERISTICS OF PERLITE LOOSE - FILL INSULATION
 It is free flowing and will uniformly and completely fills all cores and voids in masonry wall units.
 It is inorganic and is rot, vermin and termite resistant.
 It is noncombustible with a fusion point of 1260-1280 0C .
 It is improved the fire rating of an 20 Cm concrete block from 2 hours to 4 hours (improvement
100%.)
EXECUTION
Installation:-
The insulation shall be installed in the following location
 In the core of all exterior hollow.
 In the cavity between all exterior.
 Between exterior masonry walls.
Proceeding Of Insulation
 All holes and openings in the wall through which insulation can escape shall be permanently
sealed.
 The loose Perlite shall be poured directly (core via a hopper) in the top of the wall at any
convenient interval (not in excess 6 m) Wall sections under doors and windows shall be filled
before sills are placed.
 Insulation must remain dry.
2. PERLITE CONCRETE INSULATION
Perlite aggregate combined with ordinary Portland cement and water produces an ultra–lightweight
thermal and sound insulating fire resistance concrete for roof decks, lightweight floor fills, insulating

4. structural floor decks, curtain wall system, either prefabricated or insulation Perlite cement blocks and a
variety of other permanent insulating applications.
Mix Designs
Mix designs 1 and 2 (table 3) are specifically for insulating purposes and should not be used for load
bearing structures. They are ideal for the manufacture, of lightweight block for use in the construction of
non-load bearing infill walls.
Table (3): Proposed Mix Designs
# Perlite Ltrs Cement kg Water Ltrs.
Air Entraining agent
Ltrs.
1 1000 250 270 4.1
2 1000 300 300 4.1
3 1000 350 300 4.1
4 1000 400 320 4.1
5 1000 450 320 4.1
6 1000 500 350 4.1
Physical Properties of Perlite Concrete Insulation
The Perlite concrete insulation can be made with dry density of 400 up to 1700 kg/m . The lower the
density the higher the insulating value. Table 4 demonstrates the physical properties of the mix designs
in table 3.
Table (4) : Expected Physical Properties Of Proposed Mix Designs
#
Compressive
strength
kg/cm 2
Dry Density
kg/m3
1 5-6 400-450
2 8-10 500-550
3 12-14 600-650
4 18-22 700-750
5 26-35 880-830
6 40-60 950-1000
Mixing Perlite Concrete and Application
Mixing Perlite concrete methods
Perlite insulating concrete is mixed in the same equipment and by
similar methods as sand gravel concrete there are some
considerations that must be given to order additional materials to

5. the time of mixing to assure correct concrete properties and adequate yield. Also perlite concrete can be
mixed by hand method similar to sand gravel concrete. The mixing procedure used by many transit mix
operations is as follows.
o Determine the load of the mixer.
o Add to mixer the correct amount of water for the load.
o Add the correct amount of air entraining agent and cement to mixer until slurry is
formed.
Add required number of bags of Perlite concrete aggregate.
o Do not rotate the drum during transit.
o Upon arriving at job site, mix at top speed for not less than 3 nor more than 5 minutes.
o Discharge in normal manner after checking wet density for conformance to specification
range.
o Rotate the drum at idle speed when discharging last of load to assure complete
discharge of concrete.
o Do not wash out drum between load use the same trucks throughout a job.
o When mixing Perlite concrete it is generally suggested that 100 to 150 revolution of
transit mixer drum will give good Perlite concrete. This varies with the age and
effectiveness of equipment.
Application Method
 Concrete roof surface’s to receive insulating lightweight
perlite concrete shall be thoroughly cleaned with a steel brush.
 Concrete surface shall be thoroughly wetted for at least one
hour before lightweight perlite concrete is applied.
Insulating lightweight Perlite concrete shall be placed well compact to
accommodate the required level and slopes. Insulating lightweight
Perlite concrete thickness should not be less than 50 mm at any point.
 After placing insulation lightweight perlite concrete, it shall be worked out with wood floats and
steel trowels to be perfectly smooth evenly graded finish and satisfy the slope on Drawings.
Water curing shall extended for 3 days.
Recommendation For Perlite Lightweight Insulating Concrete
 The drum should be charged with water air entraining agent and cement at the batching plant,
and the Perlite aggregate should be added at the job site.
 Mixing at high speed.
 Perlite concrete should have a slump of about 18 cm.
Roofing Insulation
Perlite concrete roof deck insulation is an ideal base for built up and single roofing systems. It has
superior wind and fire resistance over other roof insulation materials and with addition of polystyrene

6. insulation board sandwiched in the Perlite concrete, high thermal resistance value is economically
achieved.
Positive drainage is easily accomplished by varying the thickness of Perlite concrete or by stair stepping
different thicknesses of polystyrene insulation board and then covering it with a uniform layer of Perlite
concrete.
Perlite concrete insulation may be placed over vented or slotted galvanized steel decking recast or pour
in place concrete or existing roofing materials proving a seamless and hard surface ready for roofing. If
exposed to water it will not deteriorate.
Re-Roofing Base
Perlite concrete insulation is ideally suited for re-roofing applications. It provides permanent, cost
effective, slope to drain designs with high R- values over flat and often- irregular substrates found in re-
roofing projects. Using a perlite concrete slurry coat, the polystyrene insulation board is positively
attached to the substrate and covered with a uniform layer of perlite concrete insulation. If the existing
substrate is sound and capable of the additional loading required, then the perlite concrete insulation
can be applied to the existing roof thereby eliminating costly tear offs.
3. PERLITE AND SAND LIGHTWEIGHT INSULATING CONCRETE
One of the most effective ways to reduce the dead load in multi- storing
building is to lighten the weight of the floors. Perlite / Sand insulation
concrete is suitable for use over structural concrete and varies types of light

7. structural forms such as corrugated steel, rib steel or cellular steel floor units and plywood sub floors.
Proposed Mix Design
Mix designs E to I table 5 specifically for dead load in multi- story building.
Table (5) : Mix Proposed Mix Designs
Cement m3 Perlite m3 Sand m3 Water m3
Entrainment
Liters
E 1 3 2.2 1.51 3.2
F 1 3 2.0 1.08 3.2
G 1 1.6 2.5 1.24 3.2
H 1 1.1 2.1 1.05 3.2
I 1 3 1.75 1.13 3.2
Expected Physical Properties Of Proposed Mix Designs
Physical properties of perlite/ sand insulating concrete vary according to mix design table 6.
Table (6) : Typical Physical Properties Of Proposed Mix Designs
Typical air dry density
kg/m3
Compressive strength
kg/cm2
Wet density when placed
Kg/m3
1 3 2.2
1 3 2.0
1 1.6 2.5
1 1.1 2.1
1 3 1.75
4. PLASTER
Perlite has been used as lightweight aggregates for plaster too. When mixed with either gypsum or
Portland cement (with or without sand). The final plasters are lightweight, fir-proof, insulating and weigh
approximately 60 % less than conventional cement sand plaster. The addition of alkali resistance glass,
polypropylene or acrylic fibers makes possible the manufacture of prefabricated steel stud, lath and
plaster exterior wall panels for high rise structures. Perlite also is basic ingredients in a number of
commercials available premixes of both plaster and plaster patching compounds designed for professional
and amateur plaster when produced for these applications.
Mixing

8. In batch mixing all required water is placed in the mixer and cement is added and mixed for
approximately one minute until the slurry is uniformed Perlite aggregate and chopped fiber is added as
the mixer is rotated. Mixing should continue until the mix is thoroughly blended but should not exceed 4
minutes.
 For machine application, 13-mm long fibers are preferred.
 On vertical application, plastering should consist of separate scratch and brown coats.
 Brown coats should be flat and even but be sufficiently rough to receive finishes.
 The base coat plaster should be kept damp for at least 48 hours.
 Finish materials may be applied after at least 5 days.
LIMITATIONS
 Portland cement plaster is recommended on exterior surfaces regularly exposed to water.
 Plaster application on any surfaces that have been coated with bituminous compounds is not
recommended.
 Long continues runs of plaster should be broken appropriately to relieve stress and strain cased
by thermal or structural movement.
5. PERLITE AS A FIRE RETARDANT
Adequate fire protection for modern demands that structural member be protected from direct attack by
flame and that the temperature of the load bearing members be maintained below the critical point at
which weakening or failure is likely to occur. Repeated tests have demonstrated perlite–gypsum and
perlite Portland cement plaster are exceptionally effective in blocking flames and retarding the
transmission of heat due to:
 The countless air cells in perlite aggregate make it an excellent insulator. perlite plasters offers
up to 4-6 times more resistance to heat transmission than ordinary sand plaster.
 Perlite-gypsum and perlite-Portland cement weighs about 60 % less than ordinary sanded
plaster.
 When exposed to fire perlite plaster releases chemically combined water in the form of vapor,
which maintains the plaster temperature at about 100oC, until all of the water has been driven
off as steam.
 Perlite plaster has low linear thermal expansion compared with sand plaster at high
temperatures, which greatly reduces the number and size of cracks, which permit heat and flame
to penetrate through the plaster barrier.
Typical Mix and physical properties
Typical mix designs are suggested in table (7). The mix is considered as a guide to the application, but
minor adjustment in proportions may be required depending upon specific brands of materials and spray
guns used. Adequate quality control on the job can be assured by enforcing density and strength
requirements.

9. Table (7): Mix design
Mix proportions Thermal & mechanical properties
Cement
(kg)
Perlite
Liters
Water
Liters
AEA
liter
Fiber
gm
Density
kg/m3
Compressive strength
Kg/cm2
50 100 33 0.4 600 1300 40-60
Perlite–Gypsum Plaster
Scope
The plastering contractor shall furnish all labor, material, equipment and supervision for installing the
perlite – gypsum base coat plaster and finish coat in accordance with the recommendations of the
perlite Design. Application of perlite – gypsum basecoat plaster and finish coats shall be in accordance
with USASI Specification A42.1
Proportioning of Base Coats
 General: all metal lath surfaces and gypsum lath ceilings attached by resilient clips shall be three
coat work, Unit masonry and gypsum lath may be either three coat or two coat work.
 Three Coat Work :
1- Scratch coat: First coat shall be not more than 60 liters of perlite to 9.3 kg neat gypsum. On masonry
surfaces, except monolithic concrete, the mix shall be not more than insulation of 80 liters perlite to 9.3
kg, of neat gypsum.
2- Brown coat: The second coat shall be not more 80 liters of perlite to 9 kg. of neat gypsum.
3- Two Coat work: On gypsum lath, the mix for double-up work shall be not more than 70 liters of perlite
to 9 kg, of neat gypsum, on unit masonry, the mix shall be not more than 80 liters of perlite to 9 kg of
neat gypsum.
4- Monolithic concrete: A scratch coat of bond plaster shall be applied to the cured and dry concrete. A
brown coat of not more than 80 liters of perlite to 9.3 of neat gypsum shall be trowel led into the scratch
coat before it has set.
Proportioning Of Finish Coat
When a smooth trowel led time putty gypsum finish is used, it shall contain perlite fines in the
proportions of 10 to 20 liters per 9.3 kg gauging plaster.
Specifications presented here in-incorporate portions of United states of America Standards Institute,
Standard Specification for Gypsum Plastering A42.1 but vary in format and content to conform to the
current recommendations of perlite Institute, Inc.