Redbacks in New Estate Fences and Retaining Walls

Why a new backyard suits redbacks so well

Redbacks need a dry, sheltered, undisturbed cavity to build a retreat in, with an opening at ground level or just above it. They do not want dense vegetation or damp ground. A new estate backyard is close to an ideal specification.

Colorbond fencing runs the full boundary and the capping creates a continuous void along the top rail and at every post. New retaining walls, whether timber sleeper or concrete block, produce gaps at every joint and along the base. Weep holes in fresh brickwork open directly into the cavity. Letterboxes, meter boxes, downpipe brackets, unused pots, stacked pavers, building offcuts left over from construction and the underside of new outdoor furniture all add more.

An established garden is far less suitable. Dense planting holds humidity, ground cover gets disturbed, and there is simply less clean dry void space. That is why the pressure in a new estate tends to ease as gardens grow in and construction moves on.

The corridors where we see it most are the western estates — Tarneit, Truganina, Wyndham Vale, Manor Lakes — and the northern growth corridor around Craigieburn, Mickleham and Kalkallo.

Why knocking the webs down achieves little

A redback web is an untidy tangle with strong vertical catching lines running down to the ground, and it is the part you can see. The spider is not usually in the middle of it. During the day she sits in a retreat at the top of the web, tucked inside the void she is living in — behind the fence capping, under the lip of the retaining wall, inside the letterbox, up in the weep hole.

Clearing webs with a broom removes the web and leaves the spider in the cavity, and she rebuilds. It also does nothing about the egg sacs, which are pale, papery spheres suspended in the retreat and can each contain a couple of hundred eggs. Removing webs without treating harbourage is the most common reason a household feels like the redbacks keep coming back.

Treating the harbourage means applying to the voids themselves: along the fence line and capping, the joints and base of retaining walls, weep holes, letterbox and meter box interiors, the underside of outdoor furniture, and around stacked or stored material. That is where the population actually lives.

Bites, and what to do

Redback bites are medically significant and worth taking seriously without panic. The bite is often not felt immediately, and pain builds over the following minutes to hours, sometimes with sweating, nausea and localised swelling. Antivenom is available, and deaths in modern Australia are extremely rare.

First aid: wash the area, apply a cold pack to reduce pain, and seek medical attention. Do not apply a pressure immobilisation bandage for a redback bite — that technique is for snake bite and funnel-web, and it is the point most commonly got wrong. Call triple zero (000) if the person bitten is a young child, if symptoms are severe, or if there is collapse or difficulty breathing. healthdirect covers spider bite first aid in full.

The practical reason this carries more weight on an estate than elsewhere is where the harbourage sits. Fence lines, retaining walls, letterboxes and outdoor furniture are all at child height or below, and they are exactly the places a child reaches into. Our redback spider guide covers identification.

What we do, and what you can do

Our spider treatment covers the harbourage across the whole property rather than the house alone, because on an estate block the fence line and retaining walls carry most of the population. Where there are young children or pets we go through which areas we have treated and when it is fine to use the yard again, and our treatments are pet and child safe when applied as directed.

Between treatments, the things that help are unglamorous and effective: clear away building offcuts, stacked pavers and unused pots left over from construction, keep outdoor furniture and play equipment away from the fence line where practical, store items off the ground in the shed and garage, and check letterboxes, meter boxes and under outdoor furniture before reaching in. On a property still surrounded by vacant or under-construction blocks, an annual treatment heading into spring is realistic until the area settles.

Call 03 9449 4244 or request a quote.