Hi.

Going to convert a detached double garage and not sure if decent soundproofing necessary. Its at least 15 foot from neghbours house+ street.

Have visions of home cinema sound spilling out to the street/neighbours in the early hours of the morning. Do you think i need to use rockwool etc when building the inner stud wall?

Thx.

[dupontin]

Originally Posted by spud999

Going to convert a detached double garage and not sure if decent soundproofing necessary. Its at least 15 foot from neghbours house+ street.

Hi Spud

I'm converting my garage at the moment, and have got some cheap help, (polish builder)
Insulating the garage is paramount, I understand you dont want to waste money if you can get away with it but the insulation is not for the neighbours

The insulation is to keep sound inside the room for your benefit.
if you had a void between the plasterboard and outer garage walls, you would get considerable resonance occuring (think of it like the room turning into a big speaker with baffles inside)

I'm even replacing my door as it has glass

I'm insulating the Roof space and curving my ceiling
Then on the concrete floor I'm putting green fibre panels normally used under wood floors, it's great for insulating the floor !

Insulate the walls the following way (cross section description)
1 outer wall of garage (brick ?)
2. airgap (think of double glazing, but this time with walls !)
3. Rockwool
4. plasterboard
5. Curtains on walls

and i haven't yet mentioned winter and summer !, the insulation is there for many reasons. mostly your comfort ! (so forget about the neighbours)
(Disclaimer: I am certainly do not profess to being an expert on this, just putting some common sense thinking into the process and talking/reading here) Hopefully some others will add from their experience

I got lots of ideas from the pictures in

http://www.avforums.com/sdw/picturehouse1.html

and i am modeling my interior on what I consider to be
"the dogs ******" or WOW

http://www.subcentral.ch
I'm sourcing fibre optics at the moment so if anyone has any (cheap) suggestions please let me know.


Cheers
Mike

[garyc]

Hi, just to add my 2 pennies

also about to start me garage conversion. and you probably already now this stuff but you should be using vapour check plasterboard and the thickness of insulation will be determined by the type used to achieve a reasonable u-value.

I guess you arn't getting building regs approval so if you move house, it can only be classed as a store room.

Let me know how you are get on?

cheers

Gary

Spud,

I converted my detatched garage earlier this year (for details follow the link at the bottom) and I primarily concentrated on the thermal needs of the room (I didn't want to freeze in the winter). However, as it's only four feet from the neighbours house I was concerned about sound leakage. Hence the 'heavy' concrete block wall by the garage doors, a double layer of plasterboard and a good sized gap between the inner wall and the outer brick (room within a room mentality). At very high levels inside all you can hear imediately outside the garage doors is a occasional distant rumbling from the sub so I'm quite happy with it.

I thought about using curtains but in the end I've used a large Ikea rug (because they are cheap and not backed) stretched out on the rear wall like a tapestry to dampen the inside walls. Works pretty well in my opinion so I may get another couple for the sides.

If you really want to go into serious soundproofing see http://www.domesticsoundproofing.co.uk/index.htm but it will cost. The accoustic matting and fibre are a lot more expensive than any insulation you would get from a DIY place and I'm sure will work much better. You pays your money and takes your choice...

Good luck with the build and post your progress.

Hatcher

[garyc]

Hatcher,

excellent web site, thanks for the info

cheers

gary

Originally Posted by garyc

I guess you arn't getting building regs approval so if you move house, it can only be classed as a store room.

I applied to my local council for planning permission (and the need for building regs) and was told that I didn't need any as it was covered under permitted development.

Another thought. I was going to put a window in the front but was told by all the estate agents I talked to that it's best to leave the doors there as it will help with selling the house later (much later that is). If a prospective buyer doesn't want the room then in their mind they can still change it back into a garage. Once the doors are gone then that will no longer occur to them.

Thx for the advice all!

Thought id learnt a bit about sound etc but i cant quite grasp the problem of sound INSIDE a detached garage. Is it because no walls are attached? What exactly is the problem??

[garyc]

'permitted development' is planning, basically letting you alter/build to your existing property as agreed with the planners and the original builder/developer when the house/houses were built.

building regs is a stated min. acceptable level of construction standard. i.e its safe for habital use. without building regs your conversion has not been checked by the local authority to meet this standard and as such can not be classed as a habital room.

I know probably teaching 'to suck eggs' and it only really is of any interest if you want to move that your conversion can not be listed a habital room just as a store!!

i agree with you leave the garage door in.

It's a fair point Gary and I've often wondered whether I should have pushed the council further, paid the £150, and got them to 'inspect' the conversion. It was all done in line with the regs anyway. I suppose it doesn't really matter as resale wasn't the point of the exercise, and I like the 'undo' option if I have trouble selling it in years to come.

I'll look forward to following the progress on your build.

Not sure I follow your question Spud but here goes;
The sound inside the garage will need to be damped otherwise the reflections will create echos just like a bathroom. This is mostly overcome with the use of furniture, chairs, settees, carpets and even wallpaper but you may need a bit more to really deaden the room. Hence the discussion about curtains and accoustic pads.

Hi Spud999,

I am basically in exactly the same position as you except mine is a lowly single garage (sigh) It is about 18 foot long so I am leaving the door in and building a dividing wall about 5 foot back from the door. By doing this I achieve a HC room 12 x 9 and a store room at the front whilst still maintaining a 'garage front' effect.

As for sound proofing I am doing the stud wall filled with rockwall bit due to cost restraints.

My fear is not the mid but trying to contain the bass rumblings. One site http://www.customaudiodesigns.co.uk/basstraps.htm seems to offer good solutions however they are all so expensive relative to my budget.

Does anyone have any good budget bass trap ideas?

Cant wait to see pictures of your progress! My build progress will be in thread 848 'My garage to HC conversion live'

Good Luck!

[Gary Lightfoot]

Just to add a few ideas - instead of a rug, you could use thick wallpaper paste and glue carpet to the walls - there are two schools of thought for sound in a multi-sound room. One is that the front screen wall should be dead (absorptive), and the rear and side walls dead below ear height, with the remaining parts of the wall and ceiling live (reflective). The other method is to make all walls dead. The floor should be carpeted in both cases.

I used the former idea and it removed all echo that was present beforehand. The 'clap test' passed with flying colours. The advantage of wallpaper paste is that it'll be easier to remove (steam) the carpet from the walls later if needed.

Another thing regarding soundproofing - once you've done the two layers of plasterboard, seal all edges with silicone or similar. Anywhere sound can go, so you need to seal those possible leaks. An inch suare hole can leak as much as 15dbs of sound, which could totaly negate any gains the insulation and plstaerboard have given you.

That includes keyholes.

Ventilation ducting should be routed as an 'S' shape to help reduce sound travel. Straight runs will funnel sound straight out.

Bass is always going to be a bugger to stop, as it vibrates anything it touches, so mass or complete isolation is all that will really work. Two layers of plasterboard help add the mass, and decoupling the new walls from the existing helps too, but the floors are still being vibrated by the sub, and that will travel.

Flexible walls help absorb bass, so using anything less than 4" x 2" for the new walls may help. Using resiliant bar can have the same affect, but isn't always the case, but it's always a good sound isolator. It's not recommended due to it's unpredicatble effects on in-room bass.

Gary.