Acoustic Ceiling Armstrong - FAQ (Freq Ask Questions)

"Armstrong Ceiling panels are relatively light. I prefer “O” brand which is denser and heavier”

• What is the use of heavier product ? Heavy does not mean heavy duty.
• Heavier panels tend to sag more. You cannot expect good RH performance for heavy products.
• Heavier products tend to have less NRC.
• Installers need more energy to carry and install.
• Heavier ceiling products need stronger suspensions & structures to hold.
• Heavier products are dangerous when accidentally fall on people’s head.

“I like to use fiberglass/rockwool. It has high NRC”

• Yes, it absorbs sound better (Good NRC), but it also transmits sound (No CAC).
• Acoustical = NRC > 0.50 and CAC > 30 dB.
• After some period, the surface layer of fiberglass/rockwools tends to delaminate.
• They are too light : not stable enough against slight air movements
• Many people are allergic to fiberglass/rockwool.
• They are not environmental friendly.
• They are generally more expensive because the demand is insignificant if compared to mineral fiber.

Why people cares more about acoustical ceilings than acoustical floorings or acoustical walls?

Floors/walls are often obstructed by furnitures. Even if expensive acoustical floorings/walls are used, their acoustical value cannot be fully utilised.

“I want a 2-hour-fire-rated panel!”

• Fire-rating is designated for ceiling-floor assembly. Its criteria is : If there is a fire in this floor, people upstairs may hav … hours to escape.
• If there is a fire: the grid can deflect horizontally and the panels drops; fire can get thru the ceiling-penetrations (lightings, diffusers, …) and heat the
• concrete slab; a shorter plenum-height helps the flame to heat the slab faster; a thinner concrete slab is easier to be heated and cracked ; …
• Armstrong “Fire Guard” products, put together with other items as specified & designed in UL Fire Directories for ceiling-floor assembly, can have …hour fire rating.

For a classroom : Does the sound reflective panels above the teacher acoustically ideal ? Not at all!

• That reflective panels will only strengthen the teacher’s voice to the first student in front of the teacher, yet it will significantly increase the reverberation time.
• A sound refelctive wall behind the teacher (plus opposite wall which it sound absorptive) is the one effective.