Acoustic Insulation under bedroom floor - suggestions?

[Possom]

Was wondering if anyone would suggest an acoustic insulation product to place under the floorboards of the floor of a 1st floor bedroom? Also, what slab thickness?

Living room underneath. I don't want to change the original floorboards for ply.

Joists are 19 cm deep.

Thanks.

 

[Stugarlinge1970]

I've used rockwool sound insulation slabs with great results, really dense slabs.

 

[Possom]

I've used rockwool sound insulation slabs with great results, really dense slabs.

Thanks, and would you normally use 50 mm slabs in between 19 cm deep joists (or thicker slabs)?

 

[Stugarlinge1970]

I've always just used the 100mm slab

 

[Possom]

I've always just used the 100mm slab

If using 100mm slab under traditional floorboards, and retaining the floorboards, do you have to lift all the boards to get the slab in or can you lift one board every so often and push/pull the slab through?

 

[Leofric]

Or quilt might be easier to fit in to suit the joist spacings. Look on any insulation company website for technical details on upgrading of sound insulation of existing suspended timber floors.

 

[wwwebber]

I used 100mm Rockwool RW3 - top stuff and is easily cut with a bread knife for installation. I didn't lift all boards and was able to slide the insulation under 3 or 4 boards width.

 

[foxhole]

I used loose lay insulation , lifted a couple of boards and made small panel on end of stick to push up to 3m each way .
But thick carpet underlay is more effective as it cushions entire floor while sound can travel easily thru timber and plasterboard around insulation .

 

[Leofric]

I used loose lay insulation , lifted a couple of boards and made small panel on end of stick to push up to 3m each way .
But thick carpet underlay is more effective as it cushions entire floor while sound can travel easily thru timber and plasterboard around insulation .

Good points, but there are different ways sound travels of course as impact, airborne and structure borne sound. So thick carpet and underlay is good in addition to acoustic insulation between joists.