Sound and thermal insulation of a flat

[Ignaty]

Hello from a newbie here!

We've just bought a flat (middle floor, but three out of four walls are external) and as it hasn't been updated in 25 years need to deal with quite a few issues there.

The major one, as I see it, is sound and thermal insulation, as heating bills in the first month of owning the flat are astronomical. We can also hear everything from one room to another.

So so far, from my limited research, I have come up with the following plan:

1. Install double plasterboards on the outside walls with Green Glue between them.
2. Install a single layer of plasterboards on ceilings (Artex at present) and internal walls, using Green Glue and screws to attach plasterboard to the walls (painted vynil wallpaper at present).

Would it help to keep noise and cold out? What would you think? Or shall I double drywall everything?

As it is a flat, I am rather limited in what I can do to walls; also, because of space restrictions I really need to have as thin new addition to walls as possible.

A related question is about electrics: at which point do I need to invite an electrician: before or after I have plasterboard fixed?

Thank you in advance!

 

[23vc]

Not familiar with green glue but unless it’s a miracle product, you’re looking at more involved solutions involving proper separation, dense insulation, stud work, sound blocking in ceiling voids etc. Plus encouraging the use of carpets over hard flooring for you and neighbours.
Yep sparky before dry lining/plastering.
The acoustic thing is a really hard one to get right, and if you get it wrong you put loads of effort in for no benefit. Worth a deep search of this forum, loads of previous posts on it.

 

[John D v2.0]

Plasterboard isn't insulation so it won't make a difference to the temperature. However it will add a bit of mass so a tiny difference to the sound.
For ceilings you would need to mechanically fix the plasterboard for obvious reasons rather than dot and dab.
Thermal insulation first look at draughts and solve them first as no amount of insulation will help if the heat blows around it. Then if you are that tight on space you would need about 25mm celotex with plasterboard on top, you could chip off the existing plaster to make more space.
For sound basically good luck, maybe get heavy bookshelves or new neighbours. A level of draught proofing might help with sounds though.

 

[^woody^]

Your neighbours will benefit more from those, as they will stop sound getting out more so than sound getting in. What you need is for the sound insulation to be fitted in the neighbour's flats. Otherwise you need a specialist to design the work rather than anyone guess it, so as to ensure that you spend money on the right things fitted in the right way.

You will potentially need an electrician before and after the works.

 

[Leofric]

British Gypsum have technical details on upgrading acoustic and thermal insulation of existing walls and floors and Celotex and Kingspan have systems for upgrading thermal insulation of external walls.