Cracking In Residential Properties
(Informative) as described in Australian Standard AS 4349.1-2007
Cracking of Building Elements
(Informative) as described in Australian Standard AS 4349.1
Use of cracking of building elements as an indicator of structural performance can be problematic. Where cracking is present in a building element the inspector has to be alert to the possibility that the cracking may be the result of one or more of a range of factors and that the significance of the cracking may vary (see paragraph E2)
E2 TYPES OF CRACKING DEFECT’S
E2.1 Determining a defect
Cracking in a building element may constitute a defect in a variety of ways. In many cases a particular cracking occurrence may result in more than one type of defect, a serviceability defect and an appearance defect.
The inspector should determine whether the cracking constitutes a major or minor defect, based on the expected impact of the cracking.
E2.2 Appearance defect
Cracking of a building element is an appearance defect where in the opinion of the inspector the only present or expected consequence of the cracking is that the appearance of the element is blemished.
E2.3 Serviceability defect
Cracking of a building element is a serviceability defect where the opinion of the inspector the present or expected consequence of the cracking is that the function of the building element is impaired.
Examples of serviceability defects resulting from cracking are as follows:
(a) Windows or doors not opening and closing properly
(b) Water leakage occurring through a building element, which otherwise should not allow water entry.
E2.4 Structural defect
Cracking of a building element is a structural defect where in the opinion of the inspector the present or expected consequence of the cracking is that the structural performance of the building element is impaired, or where the cracking is the result of the structural behaviour of the building.
The criteria for determining whether cracking is a structural defect are not solely related to crack width. Cracks 0.1 mm wide may be a structural defect while cracks 5.0 mm wide may not be structural defects. Cracking in a structural element does not necessarily indicate a structural defect.
E3 CATEGORIZATION OF CRACK IN MASONRY WALLS
Reporting of cracking in masonry walls should be in accordance with Table E1
Table E1 CATEGORISATION OF CRACKING IN MASONRY
|Description of typical damage and required repair||Width limit||Damage Category|
|Fine cracks that do not need repair||<1.0mm||1|
|Cracks noticeable but easily filled. Doors and windows stick slightly||<5.0mm||2|
|Cracks can be repaired and possibly a small amount of wall will need to be replaced. Door and windows stick service pipes can fracture. Weather-tightness often impaired.||>5.0mm, <15.0mm (or a number of cracks 3.0mm or more in one group)||3|
|Extensive repair work involving breaking out and replacing sections of walls, especially over doors and windows. Doorframes distort. Walls lean or bulge noticeably, some loss of bearing in beams. Service pipes disrupted.||>15.0mm, <25mm but also depends on number of cracks||4|
Types and examples of defects
(informative) as described in Australian Standard AS 4349.1
Table F1 provides information on defects subsets and some examples of each type of defect
For further clarification please call your local Independent Property Inspector on 1800 17 88 22
© Independent Property Inspections 2014