Finding the right Knauf product in Europe

[Starlight]

If I explain my thought process hopefully someone will spot the flaw(s) in my thinking.

1. Using Ethan Winer's Rigid Fiberglass Density Tests I can convert American in European: Owens-Corning 705 (6 pcf) is twice as dense as 703, which has a density of 3 pcf or 45 kilograms per cubic meter.

2. AIUI, 705 is ideal for bass traps and 703 for corner broadband traps.

3. Therefore, I should be looking for two products, one with 45 kg/m3 density for broadband traps, and the other with 90 kg/m3 for bass traps.

So far, so good, I hope.

4. The insulation products I see in Slovakia are mostly made by Knauf. The American Knauf web site has Knauf Acoustical Board Smooth with ECOSE® Technology which says on the page that it is available in 3.0 PCF (48 kg/m3) and 6.0 PCF (96 kg/m3).

5. The Slovak Knauf web site (English version) does not include density figures. I asked at the town's Knauf distributor but I think asking an acoustics question of a supplier to the building trade was predictably going to just get blank looks. I have sent an email to Knauf but not yet had a reply.

6. Knauf's TI 140 Decibel includes, "Intended for application in internal walls as a noise absorbing filling in grid or front-wall constructions especially in dividing walls and partitions with high acoustic requirements." It also has the highest thermal conductivity coefficient of all Knauf's products. So I ordered enough for my broadband traps and had a month's wait for the delivery to arrive.

7. Density is kg per cubic meter. Now I have the product it should be easy to calculate for myself. 1 roll of Knauf TI 140 Decibel weighs 12.25 kg. A roll contains (1.2m x 5.5m x 0.14m) 0.924m3. 12.25/0.924=13.26, so Knauf's best product is only 13.26kg/m3, not quite a third of EC703.

I am not sure where am I going wrong? I have spent months looking but keep coming back to Knauf TI 140 Decibel, which I now have and know is not the equivalent of either EC703 or EC705. Why can't I find a suitably dense Knauf product in Europe?

[takman]

Originally Posted by Starlight

If I explain my thought process hopefully someone will spot the flaw(s) in my thinking.


2. AIUI, 705 is ideal for bass traps and 703 for corner broadband traps.

3. Therefore, I should be looking for two products, one with 45 kg/m3 density for broadband traps, and the other with 90 kg/m3 for bass traps.

So far, so good, I hope.

afraid not.

you want the lowest density you can find for bass traps, and reflection panels.

seems counter-intuative, i know....but believe me i am correct. do a search on it...

[takman]

that knauf smooth stuff, probably not a good idea. i dont know how "smooth" it is, but we dont want to reflect sound, we want to absorb it....well, in the case of using reflection panels and bass traps anyways.

edit: i see it says one side only is smooth. i suppose you could have the smooth side facing the wall. you will still a reflective component of your wall panels though...

[DanDan]

Insufficient information has caused a mistake. You have my sympathy.
Many many of us face great difficulty in finding semi rigid fibre batts.
Knauf have a range called Ecobatt.
There is a large list of products from different countries at bobgolds.com
These batts have few uses and are expensive. That is why the poor distribution.
Batts are used to clad air ducts. After several years of not finding OC or rigid Rockwool, I eventually found an industrial supplier two miles away.
He carried a variety of rigid materials.
Isover High Performance Duct Cladding turned out to be very good, better than 703. Rocksil was also very good.
Isover have a big presence in Europe.
Your 140 stuff should be absolutely fine in SuperChunks.
48KG stuff has been widely used but predictions and some tests show much better performance of lighter fibres when in thick panels.

DD