Sound Proofing and Insulation

[Ste69]

I want to sound proof and insulate a shed that I use for band practise for as cheap as possible, So far I'm thinking of buying some insulation foam and maybe sponge to put in the gaps between the foam and shed walls. Would sponge be the best material to use?

[Simon Lewis]

Would sponge be the best material to use?

 

No. Foam offers just a few dB of noise transmission loss, and if your shed is made of wood, then it's very hard to stop sound going through. Furthermore, the foam used in acoustics is different from the type used for packing material. The latter doesn't work.

You need to a) increase the mass of the structure, b) acoustically isolate the noise making part from the outside (this usually means making it airtight, as well as stopping direct contact with the outside) and c) realise that it can't be done cheaply. You may have to effectively rebuild the shed - all four walls, roof and floor (i.e. a room within a room) for this to be effective. Have a look at the ready built "soundproof booths" in StudioSpares as a comparison.

 

Go and buy a book like this one, read the section on soundproofing, and save up for a large delivery of plasterboard and concrete...

 

Simon

[Ste69]

I don't need complete sound proofing, just sound reduction

[paulears]

The key, as Simon said buried in his post is mass. A timber framed structure has very little mass, so sound goes straight through. Foam and sponge won't stop the low end escaping, so if you really need to use the shed, then you will have to carry out a fair bit of work. Most of the foam and sponge products are designed to make the inside sound better, not stop it getting out.

 

Typical solutions are lining with layers of plasterboard, insulation board and maybe even mdf - 18mm - then rockwool in the cavity, and as it is likely to not be properly sealed, some kind of damp proof liner to stop mositure getting in and getting into the rockwool. The work is perfectly within the skills of the average DIY'er - but even this kind of approach (and it has to be on the cieling and floor too, don't forget), means that some sound will still get out.

 

The other downside is that all this extra mass takes up a fair bit of space, you can easily lose a foot in width once you have this kind of construction - especially if after reading the books you go for the room within a room approach. To put the kind of leakage into proportion, If you have say a single skin brick garage and build a timber room within a room, and do the kind of layer approach I mentioned above, then a drum kit going full tilt is just a faint thump outside - not 100% soundproof, but enough reduction to keep neighbours happy.

[Jivemaster]

To hide a band practise you will need signficant transmission loss in floor ceiling and walls. This means mass and multiple leaves, and separate leaves of walling. Ventilation will be a problem as will windows. Remember also that sound will pass through tiny gaps so quality joins and fittings are important.

 

Search "Camden Wall/walling/partition" under acoustics -its a style of walling used by the BBC to seriously reduce sound transmission -- Based on a stud wall with a hard (plaster) board and a soft (fibre) board on each side. There are four walls, the floor, and the ceiling to treat then the doors windows and vents to sort out, - then the gaps!

 

When you have finished the work must be substantially fire proof -- dont think of using upholstery foam or packing foam. Also the wiring must be good - no-one will hear you scream! AND the new shed may have to look like the old shed for planning/neighbours purposes.

 

Remember also that you are reducing the sound relative to the surrounding ambient. Stopping nuisance in a London town street (85dB) will need less than stopping nuisance in a quiet rural setting (typ 50dB)

 

http://www.zerogain.com/forum/archive/index.php/t-15669.html

[Andrew C]

Remember also that you are reducing the sound relative to the surrounding ambient. Stopping nuisance in a London town street (85dB) will need less than stopping nuisance in a quiet rural setting (typ 50dB)

 

http://www.zerogain.com/forum/archive/index.php/t-15669.html

ARRRGGGHHHH!!!!

We have finished the room off by installing audiophile circuit breakers from AHP ...

 

http://cgim.audiogon.com/i/vs/i/f/1134916382.jpg

 

... and two triple audiophile outlets from HMS Energia (I have two 20A dedicated lines - one for analog and one for digital).

 

http://cgim.audiogon.com/i/vs/i/f/1134916140.jpg

He's a loon, be very careful applying anything you read in that thread to the real world.

[Pete McCrea]

Whilst most people seem to be disparaging of the new Harry Enfield show, I think the guy with the shop 'who saw you coming' definately saw this guy coming.

 

I'm sure the blue acoustic treatment beneath his new concrete floor looks very much like Damp Proof Membrane...

[Simon Lewis]

I'm sure the blue acoustic treatment beneath his new concrete floor looks very much like Damp Proof Membrane...

 

A longer reply just got snuffed as Microsoft Media Player decided to close all windows without asking as it upgraded...

 

This seems to be a case of "a little knowledge.." Thick PVC can be used as a diaphragmatic absorber, but not under 2" of concrete!!

 

For the OP, total soundproofing is hard to achieve, but any worthwhile soundproofing techniques can easily be undone if you do not stop any direct air paths. It's easy to spend lots of money this way for relatively small gains.

 

You will have to undertake a fairly serious addition of multiple layer plasterboard with rockwool in the outer cavity. The floor needs something more substantial (e.g. neoprene with MDF on top, then use this as the floating floor to build the inside walls off), the ceiling needs mass, but also needs to stay up! Using the floating approach, the inner walls do not directly touch the outer skin, but will need flexible ties for strength. However, but in the case of a wooden shed (which we presume it is) the wood will offer little noise reduction anyway.

 

There are many books on this topic, together with articles in the recording journals.

 

Simon

[Jivemaster]

Have you determaned the attenuation you will need to achieve to satisfy yourself and the neighbours. That figure is a good start for planning light alterations or a major rebuild. .

[jamesperrett]

My first studio was in a shed. We thought an extra layer of chipboard on the inside and a layer of carpet would soundproof things nicely but we couldn't have been more wrong. The carpet made everything sound dull inside but the sound outside wasn't much quieter than the sound inside. The only way we managed to get away with using it for so long was because we were around 100 metres away from the nearest house.

 

Contrast that with my current studio which is on the ground floor of a Victorian semi detached house. The house is already fairly substantial but this time we went for the Camden partitions, bass trapping and plenty of rockwool behind pegboard. We can have a band playing in the studio and my wife can watch the TV in the room above and not notice the music below. We've never had any problems with the neighbours either. However, building the studio cost around 20 times the cost of my original shed.

 

Sadly you can't really soundproof a shed without building something resembling a house inside it.

 

Cheers

 

James.

[SteveB]

The crucial thing that you should remember was mentioned in Simon’s first post.

 

“Transmission Loss”

 

Any barrier, wall, partition, roof, window, etc has a transmission loss. Unfortunately the overall transmission loss is that of the worst bit. It is no good having 1m thick concrete walls and then putting a single glazed window in it, or leaving the door open.

 

Acording to Beranek ¼” plywood (shed wall???) has a transmission loss of 20dB, which means that if you are practicing at 100dB inside the sound level outside is 80dB; assuming there are no holes. However if you practice at 70dB the sound is 50dB. The cheapest method of solving your problem might be to buy a set of electronic drums and keep the practice level down.

 

If your shed has a window, a single pane of ¼” glass has a transmission loss of 30dB and double glazed with an inch gap takes it up to 45dB which is similar to a concrete block plastered both sides (Again all figures are taken from Beranek). This hopefully explains why, as others have said, it will be difficult and costly to soundproof your shed. To get above 50dB transmission loss you are getting into a serious construction project. If money is no object, the good news is that you should be able to rebuild without planning permission as long as the shed/rehearsal room is more than 5m away from your house. If I remember correctly a shed should be less than 15 sq metres floor area. The building regs people won’t be interested either as long as you don’t go above 30 sq metres floor area. Contrary to what others have said, if your shed is on a solid floor with no air gaps around the base that should be OK. If it is a raised wooden floor then, as others have said, it will have to be considered as will the roof. Any way you look at it this will be some serious DIY if done properly.

 

A third alternative could be possible depending on how well you get on with your neighbours. There might be times that are particularly bad for them (young child just gone to bed), or they might not be so annoyed if they know when you are practicing and for how long. This will also help if Environmental Health gets involved. It is a good many years since I had any dealings with them (neighbours complaining about live music venues) but if it is still the same all the technical stuff about dBs goes out of the window. If there are complaints it is too loud. This is where compromise with neighbours comes in. If they feel that they have some control over the situation they might be more tolerant.

 

My nephew (a hard up teenager in a thrash/metal/punk band) took yet another approach. They found somewhere else to practice after neighbours (200m away) complained.

 

Steve

[Simon Lewis]

assuming there are no holes....

 

But if there are, then the quoted transmission loss figures go out the window (ooh - a pun!)

 

In theory, you should achieve slightly better than the quoted reduction, as the transmitting room may be considered diffuse (although chances are it's too small for that) and the receiving room is outdoors, so therefore isn't diffuse. This is somewhat negated by the fact that it's really hard to prevent leaks and flanking paths, so it's going to be quite loud out there!

 

Anyway, wonderful though it is to see Beranek quoted here, this is getting academic....

 

Ste69, tell us some more about your shed's location, construction, the type of noise, how loud it is, when you play, why it's a problem and whether you have had Environmental Health round or formal complaints from neighbours....

[bobd]

Acording to Beranek ¼” plywood (shed wall???) has a transmission loss of 20dB, which means that if you are practicing at 100dB inside the sound level outside is 80dB; assuming there are no holes. However if you practice at 70dB the sound is 50dB.

 

If your shed has a window, a single pane of ¼” glass has a transmission loss of 30dB and double glazed with an inch gap takes it up to 45dB

 

Are you sure these figures are right? There's no way a piece of plywood is going to attenuate 20dB and the best you'll ever get with glass is with argon filled double glazing using 10mm/7mm thick glass where you will get a transmission loss of around 40dB.

 

I would be interested to know where you got those figures from.

 

Bob.

[Ste69]

Ste69, tell us some more about your shed's location, construction, the type of noise, how loud it is, when you play, why it's a problem and whether you have had Environmental Health round or formal complaints from neighbours....

 

My shed is right next to my neighbours fence which is pretty close to his house (it was purposely put here as this person has persistently been picking any little things to complain about and has been a right pain in the backside for years). I'm not sure exactly how loud the noise is, I have practise pads on my drum kit but for me to hear the guitar, bass and vocals we have to turn them up because even with practise pads on the drum kit is quite loud. We practise on weekends, usually Sundays from about 12pm-5pm sometimes not as long as that. We've had a letter from the council threatening that if we don't stop then they will take my drum kit away. Can they do this?! And also I thought it was legal if it was in certain times and not over 120DB or something like that?

[Simon Lewis]

I would be interested to know where you got those figures from.

 

I'm not SteveB, but a quick look at the nearest TL table suggests:

 

Material Plywood

Thickness mm 12mm

Weight kg/m^2 8.3

Transmission Loss (dB(A)) 20

 

The fact that the slightest gap will seriously degrade this figure, and that these tests are carried out in the absence of flanking transmission (usually a concrete test cell) means the TL figures appear higher than "real world" results.

 

Simon

 

 

We've had a letter from the council threatening that if we don't stop then they will take my drum kit away.

 

OK.... Here's my personal take on this.

 

1) The siting of the shed appears to be retaliatory. You've posted this on a public forum.

2) Five hours is a mighty long time.

3) You have had a letter from the council. They have a number of laws on their side...

 

The Environmental Protection Act 1990 - Part 3; Statutory Nuisances

This Act allows the Local Authority to deal with noise from premises which is either prejudicial to health or a nuisance. The incidents covered are of a significant nature far exceeding simple annoyance. The type of noise dealt with under the Act includes:

loud music

barking dogs and animal noise

intruder alarms on premises and road vehicles

industrial noise

 

The Noise Act 1996

Clarifies the local authority's powers to seize and retain equipment involved in causing a noise offence.

 

So, yes, the council can potentially confiscate your drumkit.

Secondly, there is no "noise limit" for nuisance.

Lastly, you are somewhat snookered. It's time to walk away from this situation.

 

4) You do not mention having a Prohibition Order placed upon you, but that seems quite possible. If an Abatement or Prohibition Notice is served on you, and you continue to play, this constitutes a criminal offence and the Courts can impose a fine of up to £20,000.

 

5) Do not try to sound proof your shed (you want to do it cheaply, and that just won't work).

 

6) Spend your money on rehearsal room hire.

 

The above is given as personal advice, not in my professional capacity.

 

Hope this helps,

 

Simon Lewis