Duplex common wall?

[samyip35]

Hi, Does anyone know if by law a duplex common wall needs to be double brick?

Ive seen some duplexes that have double brick and some which seem to only be single... and even some which seem to just have layers of gyprock or worse...?

Is there a law about this?

cheers

 

[RPI]

It is fire rating that matters. Can be done with fire resistant gyprock. Talk to your friendly neighbourhood building certifier, they are the ones who sign off on that.

 

[tez]

Boral have the partiwall system which as RPI said is fire rated appropriately.
You'll probably find the cost of a double brick wall better for sound insulation.

We originally were going to use a partiwall system but then the builder advised it wasnt much more of a cost if any.

 

[oc1]

If saving space is important then go for a party wall system like shaft liner (Boral). It is also cheaper than going double brick by about 50%.

Oscar

 

[mystery]

Not sure if this is relevant but it may be of interest and is sort of related to the topic: ..... Double brick is only a good party wall material if it has an air cavity in the middle to act as a sound buffer.

We had a situation in a townhouse where the party wall was double brick but no air cavity as the bricks were butted up to each other and the sound just traveled through it like it was paper, ... very noisy.

I also fixed Gyprock sheets over timber batons on the adjoining double brick wall .... made no difference ..... definitely needs the air gap between bricks to reduce noise from adjoining units.

The acoustic noise reduction insulation is very good for stud walls and definitely cuts out a lot of noise and is also very good in the floor/ceiling cavity in a double level building.

Mystery

 

[veseli]

To answer your question, YES there is law for it, its clearly described in BCA.

Double brick is one way of doing it, but there are other options out there, and each manufacturer has their system that could comply.

But the system must be installed and must comply with BCA.