more on soundproofing a room.

Acoustic plasterboard is one of the cheaper ways to get mass if you can take the extra floor height.

Pyrok is harder to work with - it will dull saw blades very quickly when you have to cut it. This company seels it in the UK. http://www.encon.co.uk/building/buildingboards.php I have dealt with them in Ireland and they are good. Another board to ask them about is 'Fermacell' which is not as dense as Pyrok (1150kg/m3 versus 1300kg/m3) but is much easier to work with and is still 35% heavier than acoustic plasterboard. Fermacell is Gypsum based like plasterboard but denser. I think Fermacell might be worthwile in your case to be honest. Google Fermacell flooring to get an idea of their system, they do a 20mm thick board with a neat overlap detail.

 

Fermacell is good stuff for drylining; it's a 15mm resin-bound gypsum-based board, and can take quite large point loads out of a single fixing, great impact resistance etc. As such one board product does the same job as the differentiated moisture/fire/acoustic rated board products from the usual plasterboard players (British Gypsum / Lafarge/ Knauf in the UK, and competition is cut-throat). It's also importd from Germany. Consequently it's slightly more expensive in the UK than the straightforward plasterboards - but not substantially more dense.

'Pyrok' is one name for cement-particle board, but there are several other equivalent products out there with similar densities eg. 'RCM Cemboard' , 'Bluclad' etc. All are available in a range of thicknesses, typically 6-18mm depending on what you need.

A newish product with even greater density than cemboards is magnesium-oxide board; it - like cemboards - is used primarily for sheathing but there's no reason it shouldn't be used for mass-loading also. Google for 'magnoboard'...

 

what do you guys (felix and andy) think about the fact that many of these boards are not tongue and groove?

will the sound just go through the cracks? - or is this not really a concern?

thanks for everything so far..

 

It's not a huge issue but you can use two thinner boards and stagger the joints.

 

hi andy/felix

reckon it will be the fermacell. It seems by far to have the best perormance/price ratio for this purpose. Thanks for the heads-up