Oh...dear. This is where the IIC/STC ratings are 'old school' numbers. The 'new fashion' number is called the Delta IIC. That's the number that can be ADDED to one another. Why is that you ask?

A Delta IIC is equal to the old fashioned IIC number. So we will work with that to 'ADD UP' to IIC 71 (the units of measure are decibels = dB).

Because the IIC/STC ratings are ONLY for the floor+subfloor+underlay+drop down ceiling+everything else that went into the test chambers. I've PERSONALLY SEEN companies RIG the tests so they get these MASSIVE numbers...by STUFFING the testing chamber FULL OF EXTRA materials. So much material is 99.999993% UNLIKELY to be found in a home such as yours. And to STUFF the test chamber (the noise recording studio) it COSTS THEM $55,000 for ONE floor. But...they SELL SELL SELL because they have big, beautiful, juicy numbers like STC 73 dB. Do you know how much you have to DO to a CONDO FLOOR/CEILING system to get STC 73 dB? It is IMPRESSIVE.

You need:

1. 14" concrete SLAB (found in LUXURY high-rise condos where the starting price = $2M and there are only 20 floors) = Delta IIC 47 dB (all by itself!!!)

2. 14" DROP DOWN ACOUSTIC CEILING in the unit BELOW YOU = Delta IIC 18 dB

3. 3mm Cork = Delta IIC 6 dB

4. Any hard surface floor = Delta IIC 5 dB

Total amount of 'noise reduction' = Delta IIC 76

Let me tell you how INCREDIBLY rare the above build is. It is INTENSELY rare. You *might find this in the 'High Roller Suite' in Las Vegas....in one of the newest builds. That's about it.

So IMAGINE you have a 5 story condo building. They often work with:

1.

2. NO ACOUSTIC CEILING = 0

That's it. Your NOISE reduction is 27 dB. That's IT! The ONLY thing that reaches those numbers the board requires = carpet with FANTASTIC underpad. I mean FANTASTIC padding.

And that's PRECISELY why they do this to their residents. They do NOT want to hear the HUGE amounts of complaints from the 'lower' levels. Honestly...the complaints go UP as soon as solid surfaces are in play.

Here's what you 'want to do':

1. A 6" concrete slab = Delta IIC 27 dB

2. An 8mm Vinyl floor with cork underlay = Delta IIC 18 dB

3. A 12mm cork underlay = Delta IIC 22 dB

Total Delta IIC 67 dB....oops... Didn't make it....not even close (yes...4 dB in the IIC world is A LOT).

The ONLY thing that 'beats' 12mm cork = 8mm SOLID RUBBER underpad. It is EXTREMELY RARE and if you find it:

#1. It STINKS to high-heaven

#2. It will cost you HUGE amounts of money ($20+ per square foot)

#3. It will have issues with the cork backing because cork + rubber = noisy and +++ off-gassing. The smell is outrageous (on top of the 'tire store' smell from the rubber!!!).

#4. Your vinyl plank floor WILL have BIG issues on top of so much 'compression' product.

I'm guessing your condo board has done this on purpose to STOP people from taking out carpets.