MarilynKelvin: What Are The Best Underlayments for Condos and Apartments

Dear Bob and Betsy,

I am responsible for reviewing and approving architectural modification requests for our condo association. Our documents state that our floors must have both the IIC and STC at 55 or higher. We have 6 inch solid concrete floors with no acoustical ceilings. What are the best underlayments for condos and apartments that meet our requirements? Thank you, Fred

Dear Fred,

This is a really important question! For those living in apartments or condos, and have the luxury to be able to renovate them, you will have to abide by the standards set forth by your condo/apartment association or HOA. These guidelines are put in place for you, and your neighbors, comfort and safety. One of these things that is commonly overlooked is the noise your neighbors underneath you will hear!

What Does IIC and STC Mean?

While looking at underlayment for your laminate floor, you may come across IIC-STC with a number next to them. What exactly are these and what do they mean? Put simply, these are ratings that tell you how well the underlayment will dampen sound. The higher a number is following these letters, the less noise will be transmitted. The effect of this is mostly noticeable in rooms underneath the room in which the underlayment and laminate are installed. This is why many apartment buildings, commercial offices buildings, and condo associations require a minimum rating where sound is concerned. The general ratings are as follows:

IIC-STC 70 Virtually Sound Proof

IIC-STC 60 Superior Sound Proofing

IIC-STC 50 International Building Code

IIC-STC 40 Sound Proofing below most codes

(STC) Sound Transmission Class from the American Society for Testing and Materials (ASTM) E336/E413 and (IIC) Impact Isolation Class ASTM E492/E989 ratings are measured in decibels reduced for certain types of sound. The STC rating pertains to airborne noise, such as voices, radio, television, etc. The IIC rating measures impact sounds, such as footfalls, dropped objects etc. The transmission of these sounds through floor/ceiling assemblies (such as those found in multi-level homes and apartments) will be inhibited by underlayments with higher IIC and STC ratings. The International Building Code (IBC) states that all multi-family buildings must have a minimum sound insulation rating of STC 50 and IIC 50, but yours may vary. Check with your condo/apartment association to get the exact numbers, so you make your minimum requirements.

Which Underlayments Make The Cut?

Some premium underlayments will have ratings that exceed these strict IIC and STC ratings made by most condo/apartment associations. Brands such as Kronoswiss, Roberts, Quick Step, and Floor Muffler are all perfect underlayments for your condo or apartment. Let's take a look at the wide selection available to you!

Roberts Super Felt Premium Underlayment

This underlayment is manufactured by Roberts. It is 3mm thick and comes in either 100 sq.ft. rolls, or 360 sq.ft. jumbo rolls, which are perfect for contractors looking to cover many apartments quickly. The STC Rating is 66db, and the IIC Rating is 67db. It inclused a 3? overlap and self-adhesive strip to make installation even easier. This underlayment also has a pre-attached vapor barrier to protect floors from moisture escaping concrete subfloors. The recycled fiber construction adds extra insulation and cushioning to make both residents, and downstairs neighbors happy!

Roberts Super Felt Premium Underlayment

Quick-Step Combi Value Floor

This underlayment is manufactured by Quick-Step in the USA. It is 3mm thick and comes in 100 sq.ft. rolls, measured 40in x 30ft. STC Rating is 67db and the IIC Rating is 68db, well above the minimum requirement for apartments and condos!

Quick-Step Combi Value Floor underlayment 100 sq.ft. roll

Roberts Silent 3-in-1 Vapor Underlayment

This premium underlayment is 3mm and comes in rolls of 100 sq.ft. and 630 sq.ft. jumbo rolls, which are perfect for contractors! The Silent 3-in-1 underlayment is great for use over concrete and wood sub-flooring. It can be used underneath laminate flooring, engineered, and even solid hardwood flooring! The STC Rating is 67db and the IIC Rating is 68, perfect for condos and apartments! This unique underlayment retains 96% of it's original thickness after 7 days, compared to only 57% by leading 3-in-1 foam products. The microbeads in the underlayment allow for maximum bounce back and circulation so no mold or mildew gets a chance to grow! A great, long-lasting underlayment.

Roberts Silent 3 in 1 Vapor Underlayment

Kronoswiss Provent Silent Vapor 3-IN-1 Underlayment

This is another 3-in-1 underlayment, but it's manufactured by the flooring company Kronoswiss. These rolls are 3mm thick and come in rolls of 215.28 sq.ft., bigger than the average sized roll! The STC rating is 67 and the IIC Rating is 71, which gives you even better noise absorption than the leading premium underlayment! Kronoswiss' MicroPumping System provides air circulation underneath the boards when you walk on it, inhibiting the growth of mold and mildew on your subfloor! This underlayment is also non-allergenic, so there will be no issues for residents with asthma or allergies!

ProVent Silent Vapor 3-in-1 Underlayment

Quick-Step UniSound Underlayment

This underlayment is manufactured by Quick-Step in the USA. It is 2mm thick and comes in 100 sq.ft. rolls, but don't let the thickness fool you! This underlayment has an STC Rating of 71db and an IIC Rating of 73db, making it the perfect underlayment to create a quiet oasis in your condo or apartment!

Quick-Step Unisound Underlayment

Quick-Step RealSound Advanced Underlayment

Just when you thought Quick-Step couldn't come out with even more sound-reducing underlayment! This underlayment is manufactured in the USA, is 2mm thick, and comes in 100 sq.ft. rolls. This underlayment has an STC Rating of 74db and an IIC Rating of 72db, making it an even better sound reducer than the Quick-Step UniSound underlayment. Install this underlayment if you don't want your downstairs neighbors to hear a peep!

Quick-Step RealSound Advanced Underlayment

Floor Muffler UltraSeal Underlayment

Now, for the cream of the crop, the grand-daddy of all sound-reducing underlayments, Floor Muffler. This underlayment is STC Rated 73db and IIC Rated 74db. It will be hard for your downstairs neighbors to hear anything coming through their ceiling! This underlayment comes in 100 sq.ft. rolls and 700 sq.ft. jumbo rolls, making this a contractor's dream! It's suitable for cement and wood subfloors, so it can almost be installed over anything! It even comes with a self-sealing strip to make laying it out as quickly as possible. To top it all off, it's made in the USA!

Floor Muffler 700 sq.ft. Roll and 100 sq.ft. Roll Comparison

We hope we have given you plenty of choices of underlayment to meet your condo/apartment association IIC and STC rating requirements that fit your needs and budget. If you have any questions, please write us in the comments below or call us at 1-800-520-0961!