For existing brick veneer and double brick homes, pumped cavity insulation is the practical choice, because it fills the cavity without removing internal linings. Insulbloc, our own Australian-made cubed polystyrene product, reaches up to TR 6.1 depending on the building material and construction. Batts remain the better option only where the wall is already open during a build or a renovation.
Matching the Product to Sydney Wall Construction
Brick veneer is the most common construction across Sydney’s post-war suburbs, and it has a timber frame behind a single brick skin. That frame cavity is what gets filled, working down from the roof space, with bricks lifted and re-mortared to reach the sections under windows. Because brick veneer holds its thermal mass on the outside, filling the frame is what stops the wall radiating stored heat into the room in the evening.
Double brick homes, common through the inner and eastern suburbs and in older housing generally, have a cavity between the two brick skins. That cavity is what gets filled rather than a frame. Double brick already carries more thermal mass than brick veneer, so it holds temperature longer in both directions, but an unfilled cavity still lets heat move across the wall.
Timber, vinyl and compressed fibre cement clad walls are also workable, along with plasterboard-lined internal walls. For these, small holes are cored, the cavity is pumped, and every hole is repaired and patched.
Insulbloc suits Sydney conditions for reasons beyond the rating. It is hydrophobic, so it will not wick moisture across a cavity, which matters in coastal and eastern suburbs with higher humidity. It is dust-free, resistant to fungi, bacteria and vermin, and carries a spread of flame rating of zero. Because it is dry cubes rather than a wet-applied product, it does not wet exposed wiring in the cavity.
Where batts still win is new construction and renovations with open framing. Fibreglass and polyester batts fit a frame before the lining goes on, cost less to install in that scenario, and high-density versions are the right choice where acoustic performance is the goal rather than thermal.
Working Out What Suits Your Walls?
Which product applies comes down to how your walls were actually built, and that takes a short on-site check rather than a guess from the street. You can read more about wall insulation for Sydney homes at 4 Seasons Home Insulation, or get in touch to book a free measure and quote.
