Quieting echo in tall building

[jives]

Hi all:
We are planning on a 32 x 42 pole building, with 14' sidewalls and a 6/12 interior pitch ceiling, giving it a maximum height of about 20'. When the cars are pulled out, there is room for a nice basketball court, hence the tall ceilings. The floor will be 5" of concrete. If I can cover the cost, perhaps a mat style floor covering.

The scissor trusses will allow plenty of insulation, as will the bookcase style girts.

My question, what can I do to keep the noise and echo down, especially when playing ball? The walls I plan to insulate in rockwool, which is supposed to be a good sound absorber. But if I sheet over it with steel, will that ruin its ability the absorb sound? I plan on covering the rockwool in the walls with OSB to about 8', then steel panels the rest of the way to the ceiling.

What about the ceiling? My plan was to go with 4' wide fiberglass batts (trusses are 4' apart) with skrim facing to serves as a vapor barrier and finish. No ceiling other than that.

Ideas? Thoughts?

Jeff

 

[Strouty]

A buddy of mine took some of those padded office partitions and hung them sideways from the ceiling, it helped a lot. I can't remember how many he used, he just made a pattern that looked like it would trap the sound to help with the echo.

 

[sands35]

For a DIY job, pick up something like "Corning 703" panels. They are ridged fiberglass panels. Cover them with the fabric of your choice and either hang them from the ceiling or glue them to the walls. The fabric is typically a muslin or a cotton jersey. It doesn't need to be fancy, but it needs to have a rougher open weave. Fabric is a simple way of doing it. Glue it on with construction adhesive.

Example:
(no affiliation)
http://www.atsacoustics.com/cat--Fiberglass-and-Mineral-Wool-Batts-and-Boards--106.html

Thicker panels attenuate lower frequencies. The engineering is that to attenuate down to 2-300 hz (male voice levels) you need panels ~4' thick. Not really going to happen. Part of echo attenuation is to diffuse the sound so it doesn't bounce between walls. Thinner panels (1-2") will do that to a degree.

Taking a 2" panel and hanging it at a slight angle to the wall will start to capture different wave lengths of sound. I.e., a 2x4 panel with a 2' side against the wall and the other 2' side mounted at 4-6" from the wall.

The other DIY way to kill echo is to take the tubes used for concrete piers, cut then in half and mount them to the wall. Presto - sound diffuser.

There are calculators that are used for designing home theaters to figure out where you will have standing sound waves to help with placement. The simple way is to just hang them at intervals and keep putting them up until you have happy. You don't need to completely cover the wall to have a noticeable effect.

Covering the rock wool with panels will not allow them to function as sound absorbers. You could put slots or holes in the interior covering and turn the cavity into basically a helmholtz resonator, but that actually needs to be engineered and not DIYed to be close to effective. Putting holes in a wall covering will also destroy the vapor retarding properties of the wall.

 

[jives]

Kinda what I thought. I may have to have the building up and listen to how it sounds before I do any remediation.

Jeff

 

[LS6 Tommy]

For a DIY job, pick up something like "Corning 703" panels. They are ridged fiberglass panels. Cover them with the fabric of your choice and either hang them from the ceiling or glue them to the walls. The fabric is typically a muslin or a cotton jersey. It doesn't need to be fancy, but it needs to have a rougher open weave. Fabric is a simple way of doing it. Glue it on with construction adhesive.

^^This^^
When I redid my basement I used the Basement Living Systems wall panels. They more or less invented the system and it's basically what Owens Corning sells for more money. They're rated at R13 thermal & 95% NRC for acoustic absorption. My basement is so quiet now it's like a sound studio.

Tommy

 

[sands35]

Kinda what I thought. I may have to have the building up and listen to how it sounds before I do any remediation.

Jeff

That would be choice 1.

Putting lots of cabinets and shelves on walls also helps. They break up standing sound waves.

Something to remember about insulation systems. With the exception of closed cell spray foam applied at the correct thickness - the long term viability of a building - even a metal building - requires that there is a water / vapor barrier of some sort on both sides of the wall. This prevents condensation on the inside of the wall during very cold or very hot days. (the wall construction changes depending on the environment).

So, where do you live?

 

[wyliesdiesels]

ummmm....I think this is in the wrong section! U may get more answers if its moved to some section other than electrical

 

[Aceman]

I've wired buildings that had steel liner panel installed. The sound echoes horribly in them usually, I can't imagine having to work in a shop like that running an impact, etc.

 

[jives]

Yeah, I know it is in the wrong section. . . made a mistake but I don't know how to move it. Or just re-post? Anyway, central NY, cold, damp, snowy. Roof will be steel with radiant double bubble. Outside wall steel over OSB and Tyvek. Interior wall with R19 Roxul, vapor barrier, and OSB for at least the first 8-12 feet high. Ceiling probably R30 fiberglass with white skrim vapor barrier facing.

 

[wyliesdiesels]

The admins can move it....