Legal requirement for insulation (Qld)

[Theremin]

We are building internal rooms in the lower floor of our Queenslander. The external walls are 190mm concrete block walls. They are no core filled. The idea is to put Gyprock straight into the block walls.

The draftsman didn't think there was any legal requirement to use insulation. The builder agreed, and said it would be a waste of money given the walls are concrete block. However, the certifier says we must use R1 rated foil as a minimum (this would mean we can't put the Gyprock straight onto the walls).

Who is right?!?!

[bitingmidge]

I would think that single skin block probably provides an adequate R rating (I haven't checked) but I wouldn't ever direct stick gyprock to unfilled single skin blockwork.

Basically no matter how careful you are, you will get hairline cracks in the block (concrete will shrink for many years), and dampness will appear behind the gyprock, so the foil and battens is the smart way to go, and waterproofing may be the reason for the Certifier's concern.

cheers,

P

[Theremin]

Well, after some questioning the certifier has admitted that it was just his recommendation, not a legal requirement, that we use insulation. But I take your point Mr Midge about sticking the Gyprock directly onto the blockwork - I'll discuss this further with the builder.