TECHNICAL COMPARISONBETWEEN GLASSWOOL & ROCKWOOL INSULATION

Fibreglass

/

Rockwool

Composition / KIMMCO Fiber Glass insulation products are made of thermally and acoustic efficient fiberized glass bounded with thermosetting resin. / made from basalt, dolomite, limestone.
Contains up to 25% of unfiberized materials, which means dust, fiber migrations.
Shot contents
ASTM C1335 / Nil / Up to 25%
Surface Finish & Feel / As no unfiberised parts (SHOTS) and the fibers are FINE, fiberglass insulation products is having SMOOTH finish and feel / Rockwool comprises of COURSE fiber and due to the SHOT content, it has a ROUGH finish and feel.
Thermal Performances
Thermal Conductivity (k value)
Thermal Resistance (R value) / 2-3 times less density of rock wool products required to achieve same thermal performances / 2-3 times more density of rock wool products required to achieve same thermal performances of Glass wool products
Acoustic performances
Noise Reduction Coefficient (NRC value) / 2-3 times less density of rock wool products required to achieve same acoustical performances; / 2-3 times more density of rock wool products required to achieve same acoustical performances of Glass wool products
Resistance to low frequencies
(20 to 185 HZ), generated by
HVAC equipments / Excellent
No damage / Shots are slowly breaking out from the rock fibers, under the effects of low frequency vibrations that leads to sagging of products, and weight losses.
Fire rating ASTM E136 / non combustible / non combustible
Flame spread
Smoke developed
ASTM E84/UL723 / Not over 25
Not over 50
UL 723 file R 9703 / Not over 25
Not over 50
Corrosion / Fiberglass insulation products do not cause or accelerate corrosion / Since it contains leachable Chloride and Sulphide any contact to metal with wet or moist condition may cause and accelerate corrosion. So it is not advisable to use on metal surface if the temp. is less than 150 ºC
Vibration Resistance
( sample assembly is vibrated for 96 hours at a frequency of 20Hz with an amplitude of 0.9 inch ) / The weight loss observed for fiberglass of 12 kg/m3 density – less than 0.2%
With NILL sagging / The weight loss observed for Rockwool of 30 kg/m3 density – more than 20.0%
With 5 Inch sagging

Important to know

Effect of vibration on thermal ( R value) and acoustic ( STC value) performances ofpartition wall with rock wool as cavity fill insulation element in the specified construction of Partition

Rock wool insulations made from basalt, dolomite, limestone irrespective of its manufacturer contains shot contents (unfiberized materials) in significant quantities (some times as high as 25%).

Rock wool insulations when tested for vibration resistance (sample assembly is vibrated vertically for 96 hours at a frequency of 20 Hz with an amplitude of 0.9 inches) in accordance to BS 2972 shows the weight loss of around 26.6% and sagging of around 5inch.

Sound energy is perceived as vibration. When rock wool insulation is used as cavity fill insulation element in the specified construction of Partition Wall, shots are slowly breaking out from the rock fibres under the effect of low frequency vibrations which generate sagging of products. This leads to creation of voids and thus acoustic (STC value) and thermal (R value) performances of partition wall starts deteriorating and these performances are drastically deteriorated over a period of time.

How easy to handle the material

EASE of handling the material on the jobsite is assessed from its Tensile Grab Strength which is a measure of the force required to tear an insulation material apart. A high tensile grab strength is the reflection of the integrity of the fiber-fiber bonding,fiber orientation throughout the insulation. Fiberglass has almost double the Tensile Grab Strength when compared to the ROCKWOOL. In practical terms the fiberglass does not break apart upon handling. Breakage increases cost and compromises efficiency of installation on the grab.

Because of above characteristic FIBERGLASS IS MOST ADVISABLE FOR ROOF AND WALL INSULATION OF PRE-ENGINEERED BUILDING SYSTEMS. Due to the excellent strength and light weight of FIBERGLASS it can be stretched maximum to avoid any sagging . This can avoid usage of Wire mesh to protect insulation from sagging.

On the contrary Rockwool cannot be stretched; resulted in sagging after some time ; that is why it needs wiremesh to hold . This adds Cost of installation.

forKUWAIT INSULATING MATERIAL MANUFACTURING CO. S. A. K.

Dr. Kailash Chandra

Sr. ManagerTechnical

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