Termites and Concrete Slab Homes

What are Weep holes?  –  Why do the Reports Mention this?

Many home owners assume that a concrete slab and external brick walls prevent termites from accessing their home. This is untrue. With a ‘monolithic’ concrete slab, yes the floor slab does form part of the Termite management barrier. However, Termites can gain (undetected) access in many different situations. Termites can travel over the slab edge and can travel through brick mortar joints, weep holes, service penetrations and where landscaping is against the building.  Termites can also gain access through cracks in the slab and are usually attracted to the building by conditions such as leaking showers, stored timbers or formwork. Usuallay homes built on concrete slabs (slab on ground construction) are brick veneer with soft-wood timber wall and roof frames. This timber is a high risk if located close to ground level and is easily accessed through external landscaping. It is therefore critical that a Pest Inspection is carried out for homes on concrete slabs and anything containing timber frames. Weep holes at ground level are like an open front door for termites.

termite management systems illustrations, builders drawings for kordon and granitgard

Concrete Slabs Represent Genuine Risk with Subterranean Termites.

If the concrete slab edge of the slab is concealed by concrete paths, patios, pavers, garden beds, lawns, foliage, etc then it is possible for termites to gain concealed access into wall frames. They can then cause extensive damage to concealed framing timbers. With a concrete slab home it is imperative that you expose the edge of the slab and ensure that foliage and garden beds do not cover the slab edge. Weep holes must be kept free of obstructions.

Not only do wood chips attract termites but all lanscaping timbers and substructures near ground level can attract Termites. The weep holes (gaps in brick work designed to drain water from the wall cavity) are at ground level. Weep holes must be a minimum of 75mm clear of ground level to allow detection of termite entry and for air flow through the openings. 

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Born Sydney, Australia 1974. Graduated High School Yr12 North Sydney Boys High 1991, Graduated UTS Bachelor Communications 1996, Graduated Advanced Diploma in Building Studies & Quantity Surveying 2000. Obtained NSW Builders License 2002. Worked in a range of domestic & commercial construction areas between 1995-2010. Continued professional development in 2010 for building consultant, building inspections, report writing, timber pest modules and training, chemical application etc. Obtained Professional Indemnity Cover & Commenced Sydney PrePurchase Inspections in 2010.