In article ,
fred wrote:
In article , fred writes

There may be more info at http://www.pilkington.com but they don't half
make it hard to find. If it bothers you I imagine they will do Optilam
Phon in low-e as well. Be sure to buy from/as trade if you can.

Ah, here we go:
http://www.pilkington.com/resources/...ndatasheet.pdf

Examples are 16mm gapped but I'm sure 6.8/12/6 would be just as easy
to have made up.

Interesting that the total thickness of the glass is the important thing -
it makes little difference if this is made up of a single or double glazed
unit, sound wise. Unlike secondary glazing the width of the wall away from
the main which provides a very real improvement.

--
*Sometimes I wake up grumpy; Other times I let him sleep.

Dave Plowman London SW
To e-mail, change noise into sound.