Yes. You can insulate existing walls without stripping the internal lining. In brick veneer homes, insulation is pumped down the wall cavity from inside the roof space, filling the width of the frame. In timber-framed and plasterboard walls, we core small holes, pump the cavity through them, and repair and patch the holes afterwards.
How the Cavity Is Filled Without Stripping the Walls
Removing gyprock is the method most homeowners assume is necessary, and it is the one we avoid. Stripping and re-lining a wall means plastering, sanding, painting and weeks of disruption, and the cost of making good usually exceeds the cost of the insulation itself.
The brick veneer method works from above. An installer accesses the roof cavity, locates the top of each wall frame, and pumps insulation down the cavity so it fills the space between the studs. Windows interrupt the cavity, so bricks are removed externally to reach the section beneath the sill; that section is filled, and the bricks are re-mortared back into their original position.
Timber-framed and plasterboard walls are done through cored holes. The holes are placed to reach the voids between studs and noggings; the cavity is filled, and every cored hole is repaired and patched as part of the job. It is labour-intensive compared with fitting batts into an open frame, but it delivers a higher rating than standard wall batts and leaves the room intact.
The product used for this is Insulbloc, our own Australian-made cubed polystyrene cavity insulation. It reaches up to TR 6.1 depending on the building material and construction, compared with around TR 2.0 for standard wall batts. It is dust-free, hydrophobic so it does not wick moisture across the cavity, and carries a spread of flame rating of zero.
There are limits worth knowing. Whether the cavity can be pumped depends on the wall construction and whether the cavity is clear, which is why the assessment happens on site rather than over the phone. Batts remain the right answer where a wall is already open during a build or renovation.
Thinking About Insulating Existing Walls?
If the assumption that walls cannot be done without demolition has been holding you back, it is worth having the construction checked. You can read more about retrofit wall insulation methods at 4 Seasons Home Insulation, or get in touch to arrange a free assessment.
