Read the video transcript below
This detailed video will look at sound insulation in relation to junctions in GypWall partitions, and will demonstrate the importance of taking into account levels of high sound insulation on a partition system where junctions meet with partitions with low levels of sound insulation.
Low acoustic ‘T’ junctions
First we’ll look at low acoustic ‘T’ junctions. Here we have the partition built to create the ‘T’ junction. We fix the vertical stud against the plasterboard and through into the metal stud, which has been installed to account for the fixing needed behind the plasterboard. The stud is fixed at 600mm centres.
We then continue to board the partition system either side to complete the partition.
Where we have a high to low acoustic rating on a partition, this could seriously affect the sound performance on the partition with the high level of sound insulation. The sound loss would occur through something called flanking sound, where the sound passes around the junction in the partition between the high and low acoustic partition walls.
It’s important to set out your partitions so that the walls with high levels of sound insulation run into the wall with low levels of sound insulation.
It is also important to seal any gaps with Gyproc Sealant to prevent any sound passing through walls that require good levels of sound insulation.
We then continue to insulate the wall with ISOVER Acoustic Partition Roll for high levels of sound insulation.
Finally, we fix Gyproc SoundBloc or Gyproc DuraLine onto the partition. This again depends on the system specification.
We can see that, with the way the ‘T’ junction between the partitions is formed, the partition with high levels of sound insulation runs into the run of the partition with low levels of sound insulation. It stops short of going the full width of the low acoustic partition, minimising contact for sound to travel. This is important to reduce flanking sound issues that could occur.
We then continue to fix the metal studs in place either side of the wall.
Finally, we board the low acoustic wall to complete the partition.
High acoustic ‘T’ junctions
Now we’ll take a look at our recommended optimum solution for high acoustic ‘T’ junction details. There are two methods you can use, which we’ll demonstrate now.
H3: Method 1
The first method uses Gypframe GA5 Internal Fixing Angle sections. Here we have the partition under construction, with 50mm ISOVER Acoustic Partition Roll installed.
We’re now ready to complete the installation of the GA5 internal angle component. First we need to notch the angle at the top and bottom with tin snips.
We now fix the angle into place on both sides of the ‘T’ junction with Wafer Head Drywall Screws.
As you can see, once we have the internal angle formed, we alternate the boards so they are stepped at the internal angle. The base layer of board is fixed at 300mm centres around the perimeter, with the outer layer fully fixed at 300mm centres around the perimeter and down the centre of the board.
There we have it; the ‘T’ junction is formed and we’ve created a break in the plasterboard in the cavity of the partition to provide optimum levels of sound insulation between rooms.
With the second detail, we’ll look at creating a break in the run of plasterboard at the point of the ‘T’ junction. Creating the break prevents the passage of sound through the plasterboard at the ‘T’ junction.
We’ll now install the metal studs for the wall forming the ‘T’ junction. At the wall abutment, we fix through the board into the metal studs that have been installed at the break in the plasterboard to allow for the board fixing.
We then simply continue to board the partition on both sides to completion. Creating a break in the plasterboard prevents flanking sound at this point, and provides optimum levels of sound insulation between rooms.
It’s worth noting that the two high acoustic details we’ve covered can be used on both sides of a partition where a four way junction is required.
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