Strip footings are one of the most common foundation types for buildings in Perth. A strip footing is a continuous strip of concrete that runs under load-bearing walls or rows of columns, distributing their weight along the ground.
Our team specialises in strip footing construction in Perth, ensuring that new homes, extensions, and other structures have a stable, continuous foundation.
Whether you’re building a brick wall for a house extension or supporting a series of columns, we provide high-quality strip footings that meet local building codes and stand the test of time.
In residential construction, strip footings (also called continuous footings) are typically used under external and internal load-bearing walls. For example, a standard house in Perth might have a 300mm wide by 250mm deep strip footing under its double-brick external walls, reinforced with steel bars, per the engineered design. These footings tie the entire perimeter of the building together, creating a robust base on which the walls sit. Strip footings are also common for retaining walls or masonry fences, as well as for light commercial buildings. Essentially, whenever a linear structure or wall needs support, a strip footing is the go-to solution. Because they run continuously, strip footings help distribute loads evenly, reducing the risk of differential settlement (where one part of a building sinks more than another).
Our Perth strip footing designs comply with AS 2870 – Residential Slabs and Footings and other relevant standards, ensuring proper size and reinforcement for the soil conditions. The width and depth of a strip footing are determined by structural engineers based on the load of the wall and the bearing capacity of the soil. As a rule of thumb in stable soils, the footing should be at least twice the width of the wall it supports (to spread the load) and of sufficient depth for strength and to reach solid ground. For instance, a single-storey brick wall might require a 300mm wide footing, whereas a two-storey wall could need 400mm or more in width. Thickness might range from 200mm to 400mm, depending on loads and soil class. Reinforcement, such as N12 rebar or trench mesh (e.g., two or three bars of steel laid along the strip), is placed to resist bending and cracking. Our team follows engineering specifications to the letter, placing the correct rebar lap splices and concrete cover. The National Construction Code provides deemed-to-satisfy details for typical strip footings on various soil classes, and we ensure all our work either meets these details or project-specific engineered designs.
One key consideration is soil reactivity. Many Perth suburbs have sandy soils (Class A – stable), but some areas have clay (Class H – highly reactive). On reactive soils, strip footings may need to be deeper or incorporate features like articulation joints in the walls above to accommodate minor soil movement without cracking. We have experience constructing footings in all conditions, including adding extra steel or concrete strength where needed to handle challenging ground.
Building a strip footing in Perth starts with careful excavation of a trench along the line of the future wall. Our team marks out the footing positions and digs trenches to the required depth and width, using excavators or hand tools as necessary. We make sure the trench bottom is level and on firm natural ground. If we encounter soft spots or loose fill, we will excavate those and replace them with compacted crushed limestone or concrete to ensure the footing rests on solid material.
Next comes the placement of reinforcement. Typically, we use prefabricated trench mesh (steel bars welded into a ladder-like mesh) or deformed steel bars tied in place, running continuously along the trench. We support the steel on bar chairs or bricks to ensure it’s lifted off the ground to the correct position within the poured concrete. If the strip footing will connect to a slab or pier, we may set starter bars protruding upwards to tie into those elements.
Concrete pouring is done continuously along the strip to avoid construction joints. We use a suitable strength concrete (often 20–25 MPa) and a mix design that ensures workability to flow into the narrow trench. The concrete is placed and then rodded or vibrated to eliminate any air pockets, particularly under the reinforcement. We screed or trowel the top of the footing roughly level. If the wall above will be masonry, we often leave the concrete a little rough or set keys (indentations) for better bonding with mortar, or we might cast in starter bars to integrate with the wall. Curing is managed by keeping the trench moist or covered, which is especially important in Perth’s hot, dry climate to prevent the concrete from drying too fast and cracking.
After the strip footing has gained enough strength (usually a few days), building of the wall or structure on top can commence. We coordinate our schedule to fit your project timeline, ensuring that the footings are ready when the bricklayers or builders need them.
A correctly built strip footing offers excellent longevity, essentially the life of the building, because it is a simple, robust form of construction. Spreading out loads prevents excessive pressure on the soil, thereby reducing settlement. Our strip footings are engineered to have factors of safety that account for variations in soil capacity and load over time. We also make sure to position footings below the zone of seasonal moisture change (usually at least 300mm below ground level in Perth, deeper in reactive soils), so that the ground under the footing remains relatively constant in volume and strength year-round. This helps avoid issues like foundation movement in drought or heavy rain.
Clients choosing our services benefit from our strong attention to detail and quality materials. For example, we ensure minimal water is added on site to our concrete (excess water can weaken the mix). We can also incorporate additives like plasticizers for workability or sulphate-resistant cement if your soil or groundwater has aggressive chemicals. These measures mean your Perth strip footings will remain strong and crack-free for decades. Our commitment to best practice is why homeowners and builders trust us for their foundation needs.
