Lining Garage for Soundproofing on a Budget

Maxson

jamesperrett said:

The only thing that I would add is that it would help to have some kind of flexible layer where your studs meet the floor. I used carpet underlay made from rubber crumbs. And resist the temptation to attach anything to the outer structure of the garage. This will destroy all your hard work and drastically reduce the soundproofing properties.

I'm using the floor matting under the frame so that should work. I think I have to attach to the roof. There isn't enough spare headroom to build a non attached ceiling which would require at least 6x2 timbers at a guess and I don't want to lose 6". I can add some rubber between the roof timbers and the new roof lining which should help. Most of the sound escapes through the end door at the moment so my main aim is to block that off and isolate from that. Then line the side walls and worry about the roof after that. 2/3 of the garage had already been lined with chipboard covered in carpet before we moved here so I'll just board over that.

If you go to the effort of using a double layer of plasterboard then it is better to use different thicknesses for each layer. I ended up using a layer of 19mm plasterboard plank, then Green Glue and then a layer of 12mm acoustic plasterboard. If I needed better performance I could then have added a layer of 15mm acoustic plasterboard as well but I found it wasn't needed.

That does make some sense and I'm considering it although the 19mm planks do cost more than 2x the 12mm DB board per square metre so not that moneysaving.

One other thing to think about is ventilation. A soundproof room must have no gaps in the inner layer so you'll need some way to get the air in and out. Normally you would use two baffle boxes to give you a sound attenuating inlet and outlet with a fan in the outlet to move the air through.

I hadn't considered this. I was thinking about having a roof window put in for more daylight plus which would have a trickle vent or similar for ventilation.

Maxson

I've gone with 15mm thick standard plasterboard with a 12.5mm acoustic board on top. £150 just spent at selco and coming tomorrow. That's on top of studwork in 3x2 CLS with rubber tape between the first layer of board and the 3x2. This tape seems like good value: https://www.ebay.co.uk/itm/144647393118

There are cheaper alternatives to green glue and I've seen outdoor carpet glue recommended. I'm going to use engineering silicone between the layers of plasterboard as that's also a resilient glue that stays flexible and I can get it much cheaper per tube. Not sure if green glue is worth it at £26 for two tubes per sheet of board that's £100s for enough to do the whole room. About £78 just for the end wall.

Leon_W

Couldn't you just use a plasterboard bonding adhesive like this to stick one board to the other instead of expensive glues ? https://www.wickes.co.uk/Knauf-Gypsum-Based-Plasterboard-Adhesive-25kg/p/141933?fix&gclid=Cj0KCQjwmouZBhDSARIsALYcoupHN5VmtnKqaYkleAMNs6Z8ibLgktQ6PPpGqV4qdPvQJ1MIF6gvV5oaApiiEALw_wcB&gclsrc=aw.ds  

A 25kg bag will go along way. Just apply with a notched trowel.

markin

Leon_W said:

Couldn't you just use a plasterboard bonding adhesive like this to stick one board to the other instead of expensive glues ? https://www.wickes.co.uk/Knauf-Gypsum-Based-Plasterboard-Adhesive-25kg/p/141933?fix&gclid=Cj0KCQjwmouZBhDSARIsALYcoupHN5VmtnKqaYkleAMNs6Z8ibLgktQ6PPpGqV4qdPvQJ1MIF6gvV5oaApiiEALw_wcB&gclsrc=aw.ds  

A 25kg bag will go along way. Just apply with a notched trowel.

No, it wants to be flexible for sound transmission, Silicone or that rubber tape may work.

Is the heat? a Dehumidifier could be a good way to keep damp down.

Maxson

markin said:

Leon_W said:

Couldn't you just use a plasterboard bonding adhesive like this to stick one board to the other instead of expensive glues ? https://www.wickes.co.uk/Knauf-Gypsum-Based-Plasterboard-Adhesive-25kg/p/141933?fix&gclid=Cj0KCQjwmouZBhDSARIsALYcoupHN5VmtnKqaYkleAMNs6Z8ibLgktQ6PPpGqV4qdPvQJ1MIF6gvV5oaApiiEALw_wcB&gclsrc=aw.ds  

A 25kg bag will go along way. Just apply with a notched trowel.

No, it wants to be flexible for sound transmission, Silicone or that rubber tape may work.

Is the heat? a Dehumidifier could be a good way to keep damp down.

I'm only planning to heat it for a small amount of time. I will consider a dehumidifier if damp is still a problem. I'm hoping my efforts will reduce the damp a lot as it is.

Maxson

Making progress!

Maxson

Before screwing down the second board I'm having doubts about what I'm putting between the layers. The silicone I've bought doesn't feel like I've got enough as green glue seems to come in massive 800ml tubes and two per sheet is recommended but my tubes are 310ml so that's about 5 tubes per sheet which would cost nearly as much or more than using green glue!

I've seen some suggestions that green glue isn't all that special and not worth the money. What have you used as an alternative?

How about flooring adhesive for £23.99?

https://www.screwfix.com/p/mapei-ultrabond-eco-vs90-plus-ht-vinyl-rubber-flooring-adhesive-5kg/8267h

The theory is it's some rubbery adhesive so would absorb energy in the same way. The amount of green glue recommended equals about 5ltrs so a 5kg tub should be the same amount of glue.

Maxson

I've been making progress. Thanks for the helpful advice!