Articulated Joints
These are often referred to simply as control joints and have been used by designers and builders since the late 1980s however it was not until the early 1990s that control joints were regularly placed in walls where inflexible materials such as bricks/blocks were used. From around the late 1990s they have become very important and an integral part of a masonry structure – except where a structure is built on foundation material classified as rock (class A) or similar as they are not needed because the ground is far more stable than reactive clay foundation material.
Articulated joints are also an important aspect of the Queensland building construction commissions ‘Subsidence Policy’. These vertical joints consist of a compressible material often with a flexible outer sealant, are typically 10mm wide and are usually placed vertically above or below window and door openings or where some movement in the masonry can be expected.
It is recommended they be strategically placed at 5m centres. These joints are designed to minimise cracking of masonry units and to minimise window and door jamming which can occur following natural ground movement from shrinkage (prolonged dry periods such as drought) or swelling (following rain periods), particularly where there is a foundation material of a reactive clay nature. Articulated joints are now required on all sites except those classified A and S. See also Item 4.3. “GENERAL INFORMATION” Trees. (Ref: Master Builders publication, Dec 2004-Jan 2005, Page 52, “Articulated Walling”) and ‘Cement and Concrete Association Technical Note 61’.
All too often during our inspections we identify areas which are conducive to the collection of retained ground moisture near a structure. Elevated moisture levels are known to provide conditions favourable to Timber Pest activity, particularly termites, and it is vital that every effort be made to avoid these risks. The most common causes of retained ground moisture are inadequate surface water drainage, downpipes not connected to drainage outlets, no gutters in place for roofing areas, outlet pipes for air conditioners, relief and overflow valves for hot water cylinders, corroding and join leakages of gutters and downpipes, defective or incomplete flashing and plumbing for rainwater tanks leaking. These are all issues which can be, and should be rectified, if they are in existence at a property.
