Soundproof ceiling

[OneFour7]

I intend to soundproof a ceiling in a Victorian property (built aporox 1860). I will be:

1. Taking down lath and plaster ceiling (done and horrible job)
2. Use accoustic sealant on areas where there is a hole in the floorboards (above), for example radiator pipes.
3. Using RW3 Acoustic Slab 100mm thick (60kgm3) between the joists.
4. Adding resilient bars
5. Adding 2 layers of 15mm accoustic/soundproof plasterboard.
6. Sealing the perimeter with accoustic sealant for each layer of plasterboard.
7. Skimming ceiling.

My question is before undertaking step 3, should I take any steps to seal the perimeter of the room. Which is the gap between floorboards and the solid brick wall (see pic and red squiggles). The gap appears to be approx 15mm.

If I should seal the perimeter, should it be accoustic sealant? Seems like I will use up a lot if so. Or should I use expanding foam? Or does sealing the perimeter compromise airflow and leave me susceptible to more problems in the future?

Any advice is appreciated on the perimeter sealing question and/or my general approach please.

 

[Deleted member 174758]

Use mineral wool batting (slab) cut to be a tight fit

 

[DAZB]

This will do a better job around the edges and is a fire block too.

Soudal Genius Gun Fire & Acoustic Expanding Foam

• Fire class DIN 4102 B1• Fire resistance, B2 up to 2 hours & B1 up to 4 hours depending on joint configuration• Acoustic rating - 58 dB• Insulation factor - 36mW/mK• Interior and exterior useRapid curing B2 Fire Class expanding foam with Genius Gun applicator for accurate trigger control and...

www.toolstation.com