Originally Posted by adamski
I am designing together with a friend who is an accomplished eco-carpenter and builder. The aim is to be achieve a balance of lightweight construction, strength and soundproofing. Lightweight is needed so the unit is towable, so total weight should not exceed around 1500 kg. The lighter the better in terms of towing. However it will not be moved a lot, I imagine around once every 2 months or so.
Lightweight and soundproofing do not belong in the same sentence - one does not work with the other.....
In order to soundproof to any real degree of efficiency you have to have mass - this on all 6 sides of your enclosure.
I'd like to describe the current design to see if anyone can lend some advice or suggestions.
- 2x3" stud frame
- outer wall sealed with waterproof membrane, cladded with weston red cedar which becomes very light when dry. my friend suggests waterproof breathable membrane for this but I am thinking about changing this to some kind of rubber matting to add some extra sound absorption, although this will add more weight.
- 60 kg/m3 rockwool stuffed in the frame
- inner wall attached to resilient bars - 6mm ply with spruce cladding.
Roof: curved ribs supporting 2 layers of 6mm ply glued together, with fibreglass coating to seal and strengthen.
Ceiling: Resilient bars from which 1 layer 6mm ply hangs down. 60 kg/m3 rockwool between the roof and ceiling.
Floor - 18mm ply base with sheepswool /rockwool in between slats and another layer of ply on top (maybe only 9 or 12mm)
We are trying to go for the lightest possible structure with adequate soundproofing, for low to moderate sound levels with the ability to be a small distance from any neighbours. The main concern is to be isolated from outside noises which is mainly birds and nearby traffic, plus occasional motorised tools nearby. I do not have data in dBs atm! [/quote]
I don't see this design achieving any real level of isolation, birds are the least of your worries.
However - a bigger problem is fuzzy specifications - you have to clearly define the level of sound you need to deal with - along with the level o isolation you want to achieve in order for us to make any real sense out of this.
This you may as well forget - in a space this small sub-dividing it into even smaller spaces is going to make it extremely difficult for you to treat the space. Heck - even with one larger space you are going to be faced with a very difficult task making this acoustically workable.