PERLITE FOR UNDERFLOOR INSULATION

Why Perlite Insulation? Perlite underfloor insulation is an inorganic product that does not rot, support combustion nor provide a habitat for rodents. Because of its neutral pH, the product does not foster corrosion in piping and electrical wiring that may be in the underfloor area. When used for underfloor insulation, a water repellent, dust suppressed perlite specially produced for this application is used. Perlite Underfloor Insulation Specifications Water repellent, dust suppressed perlite underfloor insulation is produced in accordance with ASTM C549-81 Type IV (water repellent and dust suppressed). Other specifications are outlined below.

Density	4.5 to 6.25 lb/ft³ (70-100 kg/m³
Sieve analysis (U.S. Standard)	10-20% plus 16 mesh (1.18 mm) 90% plus 100 mesh (0.150 mm)
Thermal Conductivity (Varies with Density)	0.27-0.33 Btu · in/h · ft² · F 0.039-0.047 W/m · K

Underfloor Applications Perlite underfloor insulation may be used under floating concrete floors, asphalt floors and floating board floors. It is especially useful when used to level floors and greatly reduces sound transmission from floor to floor, from floors to walls and from underfloor piping systems. Floating Floors Perlite underfloor insulation is most frequently used under floating concrete floors. In this application, perlite insulation is poured on the original floor surface, screeded to proper depth, covered with corrugated cardboard or lightweight boards, and a layer of oil paper. Oil paper must be used if a concrete floating floor is to be poured. A plastic film is used beneath the perlite to prevent seepage of material between cracks in floors and walls. Poured concrete floors, asphalt floors or wood floors can be laid over the insulation in a conventional manner. This system is particularly useful when underfloor heating is employed as the insulation is dimensionally stable under varying temperatures and is not combustible. Perlite underfloor insulation as thick as 12 inches (30 cm) has been applied, but 2-4 inches (6-10 cm) is the normal. Underfloor insulation over 4 inches (10 cm) should be compacted. A unique feature of perlite insulation is that particles will interlock when pressed together and settling or volume changes will not take place. Leveling of Floors A special property of perlite is its ability to flow around any roughness, unevenness or exposed installations on the base floor. This enables the easy and rapid installation of level floors. In addition, because perlite underfloor insulation is water repellent, it will not absorb water should there be a plumbing leak. This characteristic of perlite underfloor insulation will limit damage to a local area. As perlite is inorganic with a neutral pH, it will not corrode piping or electrical or communications conduits beneath the floor. Sound Insulation An area of increasing importance today is sound insulation. In construction there are three concerns: low sound transmission in construction components, low transmission between floors and walls and low transmission of sound from footsteps. Perlite underfloor insulation performs in much the same manner as multi wall systems with bulk insulation to achieve reductions in sound transmission. With perlite underfloor insulation systems, sound transmission from floors to walls is reduced by using expansion strips at the intersection of floors and walls. Sound transmission from plumbing systems is also reduced when piping is surrounded by perlite insulation within the floor.

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