On Jun 2, 4:09*pm, "Dave Plowman (News)" wrote:
In article
,
* *NT wrote:

Stuffing mineral wool in tight puts pressure on the ceiling, and over
a fair area it adds up to quite a lot of force. I wouldnt. As long as
there isnt a damp problem there I'd be more inclined to go with
papercrete, its denser, has a finer porous structure, and stiffens and
damps anything its in conctact with.

Mineral wool has f-all effect on sound transmission. Once you've got rid
of direct air borne paths you need to add mass. Plasterboard etc is
probably the easiest/cheapest way.


Any of the following would help: rigidity, mass, damping.

- Sand adds damping and some mass
- Plasterboard adds some mass
- Papercrete bonds to all around it, stiffening and damping. Mass
added is the end user's choice, it can be anything from very light to
very heavy.
- mineral wool damps thin PB, but doesnt add any mass or rigidity.


NT