Walls will be your greatest challenge, and the extent to which you can soundproof them will be largely contingent on your budget.
First off, you’ll need copious amounts of insulation. You can visit your local music store and purchase acoustic foam (big squares of insulation that have adhesive on the back) to stick to your walls. These are often used by musicians to soundproof a room when practising.
This method can be a bit pricey, however, so you can use regular shed insulation instead to save money. Keep in mind that while ordinary insulation will help to soundproof your shed, it still won’t work as well as specialised materials.
When purchased, take your insulation and tack it to the walls inside your shed. Next, take plasterboard and mount it to the beams of the shed wall. The plasterboard will add yet another layer of soundproofing protection.
Another soundproofing trick is to use as few screws as possible. Sound can often escape through screw fittings, therefore reducing the number of screws you use (while still maintaining the integrity of the shed walls) will help with your soundproofing efforts.
2. Soundproofing Your Floors
Oddly enough sound can also escape through your floors. You can tackle this issue by tacking down the carpet. You don’t have to break the bank here – any old carpet will do. The carpet will reduce the vibrations made inside the shed and thus trap in escaping sound.
Rubber gym mats are also an excellent option for soundproofing your floor. You may have to do a bit of cutting to ensure your mats cover the entire length of the floor, but your efforts will definitely be worth it when you consider the fact that rubber gym mats will serve as a far better insulator of sound than old rugs.
Windows can be a huge culprit of sound bleeding out of your shed. This is especially the case with older sheds which often have windows with fairly thin glass. To proceed, go to your local DIY store and search for a plastic sheet that you can glue to the window. This will essentially “double-up” the glass and make it that much harder for sound to escape.
If you wish to trap in the maximum amount of sound you’ll also want to insulate the roof (just like you did with the walls). Avoid using plasterboard this time around, and use plywood instead. This material is much lighter and will do a fantastic job of keeping the insulation in place.