How to fill large gaps at bottom of plasterboard wall

[redhexagonal]

So I just had a new chipboard floor glued and screwed in after adding noggins and levelling the joists. There are gaps between the edge of the chipboard and the blockwork, up to 15mm. There is a gap between the dot and dab wall and the new floor of up to 40mm high amd 30mm deep and also the void underneath the dot and dab.
I want to seal the floor and walls to maximize sound insulation and draftproofing. I was going to use acoustic mastic for this but these gaps are too big at the base of three of the walls. What is the best practise to seal these gaps ? Thanks

 

[Alastairreid]

Expanding foam.

 

[redhexagonal]

Expanding foam.

Is there anything else I can use? This will be a bedroom so I’m not keen on using products that emit VOCs. Backer rod maybe?

 

[SFK]

I’m not keen on using products that emit VOCs. B

For the linear gaps you could use Lots of tubes of cheap solvent free brandless 'no more nails'.
For the cheap stuff I suggest the Wickes version.

 

[redhexagonal]

I’m not keen on using products that emit VOCs. B

For the linear gaps you could use Lots of tubes of cheap solvent free brandless 'no more nails'.
For the cheap stuff I suggest the Wickes version.

I think that might crack if I filled between wall and floor, not very flexible. What about expanding foam tape? Could that work to seal air gaps in the floor/wall?

 

[Captain Nemesis]

This will be a bedroom so I’m not keen on using products that emit VOCs.

So I just had a new chipboard floor

https://www.doityourself.com/stry/everything-you-need-to-know-about-particle-board-outgassing

https://en.wikipedia.org/wiki/Particle_board#Safety

 

[redhexagonal]

https://www.doityourself.com/stry/everything-you-need-to-know-about-particle-board-outgassing

https://en.wikipedia.org/wiki/Particle_board#Safety

Great. What should I be most concerned about? I have no idea what the relative risks of these materials is. I know expanding foam can emit isocyanates which sound worse than formaldehyde, but have no idea if a new chipboard floor itself is more hazardous than filling a gap with expanding foam around its perimeter...or what the time scales are for emission of their VOCs

 

[SFK]

Might be best if you just close your eyes and open your windows to vent your house.
Especially if you are going to lay new carpets (which have their own out gassing issues).

 

[redhexagonal]

Might be best if you just close your eyes and open your windows to vent your house.
Especially if you are going to lay new carpets (which have their own out gassing issues).

Its looking like thats my only choice. Unfortunately I need to replace the floors in 3 more rooms...the joists arent secured into the I beams and the boards arent glued or screwed so the floors are a mess.