The Hills sits on Wianamatta shale-clay — a reactive soil that swells when wet and shrinks when dry. That movement cracks slabs and footings and breaks down damp-proof courses, while the clay holds water against the base of the walls. Both older brick homes and newer brick-veneer estates get rising damp and moisture through cracked slabs as a result.
Reactive-clay sites need the cause pinned down — rising damp through a failed course, or moisture through a cracked slab edge. We diagnose which, then treat with DPC injection, slab-edge work or drainage and a breathable, salt-resistant render.
The Hills district's mix of older homesteads and newer estates sits on reactive clay and shale. The clay swells and shrinks with the seasons, cracking footings and slab edges and breaking down damp-proof courses, so moisture rises through older walls and pushes in at slab edges in newer homes, blistering paint and blowing plaster.
The Hills' clay-soil blocks hold moisture under the floor long after rain. We install subfloor ventilation to dry the underfloor and clear musty air.
Reactive clay cracks footings and breaks down the DPC. Our rising damp treatment injects a new course to stop the rise.
We strip salt-damaged render and re-coat with salt-resistant replastering.
Our mould removal clears it and fixes the damp behind it.
We waterproof and tank retaining walls, wet areas and below-ground walls.
Book a free damp inspection for a clear diagnosis and fixed quote.
The Hills is built on reactive Wianamatta shale-clay that swells and shrinks with the weather, cracking footings and slabs and breaking down damp-proof courses. The clay also holds water against the walls, so rising damp is common in Castle Hill, Baulkham Hills and Kellyville.
All of them — including Castle Hill, Baulkham Hills, Kellyville, Bella Vista, Rouse Hill, Norwest, Glenhaven, Dural, Winston Hills, West Pennant Hills. If your suburb is not listed, call us; we cover the whole area.
Yes. On reactive clay in The Hills, soil movement can crack a slab edge or compromise the damp-proof membrane even on newer brick-veneer homes, letting moisture into the walls. We check slab edges and drainage, not just the walls.