Avoid triple leaf... why??

hugo_inside · Post by **hugo_inside** » Mon Jan 31, 2005 4:43 pm

what is the phisical reason of this theory?? i'm building two rooms with diferent heigh and there will be two block walls agaist each other. But one room is at 3 meters high and the other at 4 meters high. If I don't wanna get into triple leaf, because one room will be isolated with rockwool and sheetrock, must be the two walls pasted??

rod gervais · Post by **rod gervais** » Tue Feb 01, 2005 12:58 am

Hugo,

If you do it exactly the way you have detailed - with the air between the walls open to the space above......... then it isn't going to be a 3 leaf system.

One of the things required for a leaf to be a leaf is the air acting as a spring - and thus the cavity must be sealed.

Even if the outer room was a completely sealed cavity - the volume will be large enough to never effect the wall assemblies.

Rod

z60611 · Post by **z60611** » Tue Feb 01, 2005 9:43 am

Rod:

One of the things required for a leaf to be a leaf is the air acting as a spring - and thus the cavity must be sealed

I remember asking Eric Desart once if it would make a difference from a TL point of view if the airspace under a floating floor were open to the airspace in the walls. His reply was something like: no difference because of the inertia of the air in the middle of the floor wouldn't make it as far as the walls.

rod gervais · Post by **rod gervais** » Tue Feb 01, 2005 11:05 am

z60611 wrote:Rod:

One of the things required for a leaf to be a leaf is the air acting as a spring - and thus the cavity must be sealed
I remember asking Eric Desart once if it would make a difference from a TL point of view if the airspace under a floating floor were open to the airspace in the walls. His reply was something like: no difference because of the inertia of the air in the middle of the floor wouldn't make it as far as the walls.

you're talking apples and oranges here Z my friend.

create a box within a box - with a small air gap all around - 2 leaf system - and ask me if opening the bottom sealed air space to the sides will make a difference in TL - and my response will be the same -

On the other hand - take 2 boxes and set them seperately in a room - place boxes within each of them and ask me if it's a 4 leaf system - I'll tell you no.

We create "4 leaf systems" ALL THE TIME in hotel construction without problems because we seperate them by a hallway........ and we get great isolation.........

I stand by my previous response. ..........

Rod