Sound dampening idea

[Aussie Yeoman]

Hi all,

I had an idea for some basic sound dampening, and thought I would run it by the hivemind.

When hammering in a tin shed, sometimes the hammering turns the whole shed into a massive drum, reverberating for many neighbors to hear and loathe. Other times the high-pitched whine of grinder or saw pierces many walls.

So to combat this, I was thinking of getting old carpet, the shaggier the better, and screwing it to one side of either large plywood sheets or plaster panels, then attaching these to the inside of the shed wall, with the carpet between the plywood and exterior shed skin.

The carpet would be free or muchos cheapos from carpet laying companies that remove and throw away old carpet, and the plasterboard or plywood would be reasonably affordable.

Thoughts?

[losthelm]

Good idea with the plywood/sheet rock.
The carpet may be a problem, used carpet can have all sorts of biological contaminants that will spawn with just a little water and darkness.
Though that's not realy a problem if you can ensure clean carpet.
The bigger concern is fire and collecting flammable material in the fibers.

Treated canvas maybe a better option, though it can also collect grim over time.

[wcallen]

I expect one layer of wood/drywall will do a lot.

Just having 2 dissimilar layers with air in between can change sound transmission dramatically.

A layer of fiberglass insulation will help some too, and it has the added side effect of helping with the heating and cooling.

The carpet would likely have similar effects. It will certainly absorb sound. Some of that stuff is pretty artificial, so it likely won't collect a lot more than anything else up there. The animals sure seem to love to mess around with my ceiling.

Wade

[Steve S.]

I would try insulation. Perhaps the pink foam kind you can buy in 4x8 sheets. Even 1/2" thick stuff would go a long way.

Steve

[wcallen]

I would try insulation. Perhaps the pink foam kind you can buy in 4x8 sheets. Even 1/2" thick stuff would go a long way.

Steve

I have an example to work from. My house is insulated with foam. It works great as a heat/cold insulator, but it really feels like I get more sound through the walls than I have in any other house. I don't know this to be the case for sure, but I expect the goofy holes in fiber glass would be better and cheaper. Or you could use open cell foam like they seem to use in recording rooms, but I bet that would be more expensive.

Now, maybe we can find someone here who actually knows about sound deadening.

Wade

[Kristoffer]

Sound dampening needs to be adressed on many levels since different wavelengths of noice travel trough different media differently (?!)

A combination of different (!) materials is the best. One old trick is to use cardboard egg trays and staple those up on all the walls and preferrably the ceiling. Then cover them with insulation out of mineral wool or perhaps open cell spray foam. The oc spray foam stops sound pretty well because it leaves no gaps where sound can pass without having to go trough some kind of media as it can do in the joints between sheets of mineral wool and studs. The more layers of different materials you add, the bigger the chanse is to stop sounds in different pitch.

A good thing is to put up stuff on the walls too. Often in music studios you have odd shaped objects on the walls. Those objects stops sound from bouncing around, resonating inside the "box" that is the room. By having stuff in there, less resonation will occur. Compare an empty apartment or house with a furnished one. Huge difference in the sound levels.

Please put up some gypsum boards and even sheets of mild steel as fire protection on the inside. These sheets will also help stopping a lot of noice.

[Cap'n Atli]

Be very careful if you do any hot-work. Flame spread on any exposed vertical carpet or other inflammable material on the walls can be rather sudden.

Sometimes placing (fire proof) sound-absorbent tiles at the three surfaces of your ceiling corners and other like locations can be useful.

So, think fire resistance as well as sound absorption. The plywood sandwich is a good idea, but please don't quit halfway.

[Aussie Yeoman]

Wow. That's a lot of response!

A few points -

I would consider using fibreglass, but wanted to air the carpet idea as a nearly free alternative. If it should be that carpet is too dangerous for whatever reason, I will bite the bullet and use purpose-made insulation.

Would not several dozen square meters of egg cartons either cost quite a bit, or take a very long time to accumulate?

I was going to ensure that neither flame nor water would reach the carpet which would be sandwiched between wood (or plaster) and outside skin. I believe there might be some form of fire retardant paint to slap on plywood, or plaster in non-flammable anyway.

Again, I'm after a super cheapo way to insulate against sound, but if that can't be done safely, I'll go the regular route. But still be influenced by price

[RandallMoffett]

I have held of doing anything like this in my shed for reads of something catching fire. I usually work outside but lately with all the snow I have risked it a bit. I found a place with basically fireproof panels of insulation that seems ideal for this. They go between the drywall, which also should be fire retardant.

RPM

[Kristoffer]

Egg cartons can probably be aquired free from somewhere, but it might take a while to gather enough of them if you cant find a pallet somewhere. Check with your local egg producer

[Amanda M]

Fire hazard would also be my main worry. I have studied some fires for school involving carpeted walls and the rate at which fire spreads on it is pretty disturbing.

[losthelm]

What type of form are you working on?
A lot of the same steps you would use to reduce ringing on a helm can help reduce the harmonic feadback you have in your workshop.
a few small things that can help is leaving the door open and increaseing the mass of your work bench.
water, cat litter, wood chips ,gravel all can help reduce sound transmited to your structure.
The exposed plywood should not be much of an issue with fire, unless space is very tight near your grinding, welding, or hot work area then I would look at cement board or putting something more fire resistant in that location.
A treated canvas drape or curtain may be enough if you have acess to fire resistant material.
Over time they can collect oil, grease, and other wise wearout reduceing the effectiveness of the material.