Re: Re: Hot knife for HA conduit ...

[Chris Hunter <cjhunter@xxxxxxxxxxxx>]

'good question !   Indeed, we might use Fermacell, it's what we
intended, also for the ceilings (double layer, with foam between) but
if we do it would have to be bonded to the polystyrene (the
recommended way, as it happens, but necessary, in any case, for good
acoustics) ... not sure how we would fix timber or metal framing,
without short-circuiting our acoustically isolating floated-floors,
but using it in any case would give us skinned hollow voids which,
even with heavy & fibrous Fermacell, would tend to drum, which we are
more than keen to avoid ... the house where we are now has routine
dot & dab plasterboard, and the acoustics are terrible (ie: every
small noise comes right back at you, is exaggerated, and puts us on
edge, plus playing the hi-fi at anything like optimum volumes results
in awfully - for want of a better word - flabby sound) ...

getting the acoustics right has been a big thing for us ... ie: 'has
involved a lot of trouble, not only in terms of structure, but also
in terms of drains & ventilation pipes, plumbing, conduits, etc ...
trouble is, small details have big effects on the final result ...
small holes & gaps can let sound through very disproportionally, and
panels can cause bad reverberations ... we're aiming for both a
neutral acoustic & good isolation between rooms ... so things don't
have to be loud, and even if they are they don't have to be louder or
annoying people in the next room / outside ...

that's how it is for us, anyway ... and it's part of the reason our
HA installation is behind schedule (we're working on it now, and it's
a lot of work, needs a lot of care & attention detail, and makes
selecting technologies & suppliers for things like heating systems
&
floors, as well as walls, very far from simple ... !!

Chris


On 19 Sep 2007, at 22:47, Ian Lowe wrote:

> As a general question, why cut the conduit into the ICF at all?
>
> would it not be better to use a metal or timber framing inside the
> ICF,
> then skin it with Fermacell?
>
> so you get the best of both worlds - super insulation from your ICF,
> incredibly tough, smooth walls from the fermacell, and accessible
> voids
> for cabling with the framing?