Acoustical Coating

Before going further in discussing an acoustical coating, it would be best to first describe such a product and its typical application.

The greatest demand for an acoustical coating is to refinish the surface of a product that has an acoustical property (it absorbs sound) and the intent is to apply this new finish without damaging the sound absorbing quality. Again, the greatest demand is for ceilings … hence the term “Acoustical Ceiling Coating” is a common term.

Whatever the case, a distinction should be made between a conventional paint product and an acoustical coating. Further, there should be a concern that if the wrong product is applied to an acoustical surface, it cannot be removed easily and the cost for such a mistake could be considerable. The intent of this article is to provide some insight as to what an acoustical coating is capable of doing and some suggestions on how to go about identifying one with a degree of confidence before it is applied.

What the Acoustical Coating is Able to Do

First, look at the surface of an acoustical material such as an acoustical ceiling tile, or acoustical plaster. Notice that there are little holes or crevices throughout, or often course irregular surface textures. Below the surface there is a softer spongier material that is designed to absorb sound.

There is only one way that the sound waves can pass through the outer surface and be absorbed by the spongy inner material and that is through the holes on the surface. Therefore, any coating that is applied to the surface must be formulated to leave those holes open and not plug them up with paint pigment. The acoustical coating, therefore, is a “non-bridging” material. In other words, the molecules of the product will not link up to span or “bridge” a gap or other open spaces.

How to Select an Acoustical Coating

As stated, once the material is on the surface, it is too late to learn that it is not a true acoustical coating. The research must be done before the purchase, not after it. A label or brochure, produced by the neighborhood printing company, may contain many claims but that in of itself should not satisfy the more discriminating buyer. After all, they will print whatever copy is given to them.

Legitimate acoustical coating manufacturers have their products tested by independent laboratories in order to (1) ensure, from a product development perspective, that the product performs as intended, and (2) support the claims they intend to make in their promotional literature. These laboratories use the appropriate ASTM Test and since they are independent, they produce test data that are impartial. UL and FM Approvals are examples of accredited laboratories in the United States that are highly respected for their independent testing procedures.

If the product manufacturer can produce reasonably current test data that shows that the application of their product has no negative affect on the sound absorbing quality of the surface material, then it is safe to consider its purchase. One must be sure that the testing has been repeated recently, as formulas can be occasionally modified, particularly during harder economic times, when the cost of quality raw materials is on the rise.

Another test that is commonly run on an acoustical coating is a fire test. In other words, if there were a fire, how fast would the flame spread with this coating material on the surface? And further, in the burning of that surface material, how much smoke would be developed? Since people die more of smoke inhalation than heat, this is an essential consideration in selecting a product.

The better the acoustical coating, the slower flame spreads and the less smoke is developed. That is why most quality acoustical coatings carry a Class-A fire retardant rating.

One last word on independent laboratory testing has to do with product approvals. Independent laboratories offer a product approval classification. If a product is “approved” by a laboratory, it means more than they have tested the material. It means that they make periodic visits to the manufacturing facility in order to determine that the formulation remains consistent and that quality control procedures are in place and used.

Therefore, prior to selecting a product to be applied to an acoustical surface, check for independent laboratory testing and if possible, an “approved” product.

Comments (9)

I have a inquiry for acoustical coating inside a auction house

the place has plane painted block and flat one inch aluminum paper coated ceilings with seams taped over

the floor is plain cement floor and about 10′ ceilings its approx 2000 or 3000 square feet

I am wandering what kind of improvement would occur and if there is a way to calculate it?

Dear Sir,
This is for your kind information that, we are coming up with a
satellite channel in Bhubaneswar,Odisha during Dec-2013.
We are having 2 no studios- for news & entertainment.
The sixe of the entertainment studio is 90′ x 40 ‘ x 18′ and the
news studio is 30′ x 20′ x 12’.
We want painted acoustic treatment in both the studios.
Please send us all related information along with cost factor.
Please treat this as very urgent and do the needful.
Thanks & regards.


The acoustical coating could only be applied to surfaces that are not easily rubbed and soiled, as these materials are deigned to absorb sound and are not hard paints that can be scrubbed clean. That limits the areas that can be treated via this route. It is difficult to predict the amount of improvement accurately.

I’m on a committee to restore the historic Walton Theatre. Our ceiling in the house is acoustical tile, all of it old, stained and at worst, missing. We cannot afford a new ceiling, and we’re pretty frightened at the thought, because we currently enjoy fabulous sound for both live performances and movies. We need to replace some tiles, and would like to be able to “paint” it a uniform color so that it looks decent. Can you tell us what you would recommend? I have pictures.


Sorry for the delay in responding. Too much travel.

At any rate, you are moving in the right direction. Obviously, I would not mind seeing the pictures. But in general, you want to use a product we manufacture under the name of “ProCoustic.” Additionally, I have a couple suggestions. First, go to the Tech Data page on our website and you can download a “ProCoustic Summary of Testing” page. This provides you with independent laboratory test data that should make you more comfortable. ProCoustic test results show a slight improvement in the acoustical quality. It is the only product that I know of that performs that well.

Secondly, I would be pleased to talk with you on the telephone and give you some suggestions on how to go about the project, for the best results. Call at (781) 767-2270 and ask for Ken.

ProCoustic was used in the renovation of the San Francisco Opera House and many other facilities of this type through the years.

Andi: Please call me at 781-767-2270 and we can more easily go over all the details. That way, we can be of the maximum assistance.

Ken Woolf

I am a volunteer at my church. We are trying to spruce up our sanctuary, fresh paint, new banners, etc. The chancel area has a wonderful resonant sound for our choir and we don’t want to jeopardize that. We were thinking of putting up a textured wallpaper or doing a textured paint on the front wall of the church (which is actually behind the choir when it sings). We thought the textured wall would add a lovely character to the chancel, but I’m concerned about it having a negative impact on the sound. What would you suggest.

Where can I buy ProCoustic?

I have an acoustical wall panel that has a water stain from a roof leak mounted in a dome at the Knoxville Convention Center. The panel was manufactured by Decoustics and the material is laminated to fiberglass and then painted. The panel is made in a circle and is also concave to fir the dome. Do you have a material that can be used to cover the stain and can you match colors ?

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