Fiberglass batts between joists?

[tew1]

I'm just wondering why I have seen new homes built with fiberglass between the joists on the inside (e.g. upper floor or ground floor with insulated basement below) or in internal stud walls. Is this purely to reduce sound transmission? Reason being, I'm installing wood flooring upstairs in my 1930's house, and wondering whether I should lay fiberglass between the joists for sound proofing? It seems like a substantial expense for minimal gain.

 

[noseall]

The laying of sound suppressing material between joists is more like modest expense for minimal gain.

I agree the benefits are mainly for high frequency noise deadening but it is hardly wallet breaking expense. Plus it will also help reduce the movement of air.

 

[tew1]

The laying of sound suppressing material between joists is more like modest expense for minimal gain.

I agree the benefits are mainly for high frequency noise deadening but it is hardly wallet breaking expense. Plus it will also help reduce the movement of air.

it's a big area, and I'd have to take up a lot of the existing floorboards is all. Just not sure what most people do? Does flooring underlay usually provide enough sound proofing?

 

[noseall]

Oh i see, i thought you were removing the existing floor boards regardless.

The answer is no. I would not rip up floor boards or drop a ceiling just to install acoustic insulation.

I would however, consider fitting it if the floor void was open.