The definitions on general cracks used by M/s AV Consultants Pte Ltd for the purpose of the Pre-Condition / Pre-Construction Survey Reports are as follows:-
| Size of Cracks | Definition |
|---|---|
| Less than 1mm | Fine Cracks |
| Between 1mm and < 2mm | Medium Cracks |
| Between 2mm > 2mm | Large / Serious / Wide Cracks |
Further inspections by competent persons are required to determine whether it is a superficial or structural crack.
Fine Cracks on Pool Deck Tiles
Base on the definition, fine crack is when the width of the crack is less than 1mm. This crack could be due to substrate problem. The tiles could have been laid over a construction joint. Expansion and contraction or movement of the joint resulted in such straight crack. However, a detail inspection has to be carried out to determine the actual cause.
Fine to Medium Cracks on Floor Tiles
The definition for fine to medium crack is when the width of the cracks ranges between less than 1mm to greater than 1mm but less than 2mm. These cracks are usually found on pavement with heavy human traffic or with some equipment like trolleys running over the pavement tiles. These cracks also appear on old pavement or could be due to poor quality tiles or workmanship issues.
Large Crack on Boundary Wall
The definition for large crack is when the width of the crack is usually greater than 2mm or more. Such cracks appear as a result of the foundation in which the boundary wall is subjected to significant ground settlement. This may occur if the boundary wall is not constructed with solid foundation like piles beneath the reinforced concrete base or with unstable soil conditions.
Medium Cracks on Base of Swimming Pool (Fiber Glass Type)
Medium Cracks would indicate that width of the crack is greater than 1mm but less than 2mm. Such cracks are hard to capture as they are at the bottom of the pool as it is filled with water. The constant movement of the surface water makes focusing of the camera very tough. Patience is the essence as the Surveyor has to wait till the water surface is less turbulence before capturing the defect.
As this is a fiber glass type of swimming pool, the crack may be the result of a weak foundation or differential ground settlement on which the pool sits on.
Medium Cracks on Vehicular Bridge Girder
Base on the definition, medium crack is when the width of the crack is greater than 1mm but less than 2mm. The cause of the crack on this structure is unknown as it is located at high level under heavy traffic conditions. A detailed inspection has to be carried to determine the cause using a boom lift and proper traffic control.
Water Stain Marks on Ceiling
This situation is the result of water coming into contact with the ceiling board from the above. However, we must not immediately conclude that the defect is due to water seepage by the elements. Detail inspection has to be carried out to determine the source of water and to conclude on the root cause.
Ground Settlement
This usually occurs for buildings which were built many years ago. As the ground settles over a period of time, structures that are not sufficiently supported will settle more than the surrounding structures. In this instance, the drain which possibly is not sitting on any solid foundation settled more than the apron resulting in large gap between them.
Barren Turf on Side Table
Such occurrences can be seen on side table, grass verge or landscape area adjacent to public roads. The barren turf area is being heavily used by human traffic or bicycles taking short cut or contractors working in the vicinity placed their materials, equipment or machinery on the grass verge.
Medium to Large Cracks on Plastered Walls
Base on the definition, fine to large crack is the width of the plaster crack starting from less than 1mm and gets larger than 2mm or more at other parts. If the cracks only appear on the plastered wall / façade then they usually do not have an adverse impact on underlying structure. Such defect may be the result of poor workmanship, insufficient surface preparation or impure material resulting in poor adhesion between the surfaces.
On the contrary if the crack has penetrated through the sub-base then the building element has been subjected to tension forces. This may be due to ground movement, settlement or instability.
Medium to Large Cracks on Pavements
A medium to large crack refers the width of the crack greater than 1mm but less than 2mm on some part of the crack and greater than 2mm or more on other part of the crack.
Pavements are usually constructed over compacted ground without solid foundation. The thickness of pavement usually ranges from 100mm to 150mm thick with minimal reinforcements. Hence, pavements are subjected to ground settlement over a period of time and this resulted in the cracks. The severity of the cracks depends on the thickness, usage and compactness of the ground.
Medium to Large Cracks on Façade
Base on this definition, medium to large crack is when the width of the crack ranges from greater than 1mm but less than 2mm on part of the crack and greater than 2mm or more on other part of the crack. Such cracks usually appear on the façade of aged and low-rise buildings and may also due to no maintenance as the buildings are abandoned or waiting to be renovated. Older and low-rise buildings do not have strong foundation like what we have currently, besides that the ground on which these buildings are constructed had settled over the years.
Large Cracks on Apron
The definition for large crack is when the width of the crack is usually greater than 2mm or more. For this case, the apron has settled and also slides away from its original position. The evidence of the slide is noted as the apron protrudes out of the drain wall. The reason for such defects could be that the apron is non supported on solid foundation and the ground settled over a period of time. In addition, the apron is a top-up concrete over the existing apron. There is insufficient bond between the two aprons.
Large Cracks on Tarmac Road
Cracks that appear on tarmac road, the width of the crack is mostly large (greater than 2mm or more). Such characteristic is due to the composition of the tarmac, a mixture of bitumen, fine and coarse aggregates. Crack on tarmac usually occurs when the course aggregated separate from the bitumen resulting in large crack.
Tarmac crack appear may be due to the following factors:-
- The road is heavily used by vehicles
- The road is used by very heavy vehicles
- Prolong rainfall at that area
- Week sub-base or base course
Joint Separation / Large Gaps between Wall Tiles
One of the factors such defect appears could be due to the substrate in which the tiles are laid. It may occur when the tiles are laid at the junction of a brick or masonry wall and reinforced concrete (RC) column joint. RC column is much sturdy structure while the brick wall is not. In the event of structural movement, separation of the brick or masonry wall occurs then large gap appear and this is highlighted by the tiles joint.
A further detail inspection may have to be carried out to determine the underlying cause.
Misaligned Gate
The misaligned gate leaves are due to one of the gate leaf that has sagged. This defect may look common and unsuspecting but may result in dispute between neighbors. The neighboring unit may claim that the sagged gate was the result of the adjacent construction works.
Dented / Damaged OG Boxes
This is a common sight along the public roads, especially if there are construction works nearby. Contractors working or loading / unloading adjacent to the OG Box did not take sufficient care or protection for the equipment resulting in knocks / accidental damage to the electrical terminal box.
Elfflorescence on MRT Tunnel Walls
Efflorescence on MRT Tunnels is an inevitable occurrence as tunnels are constructed deep underground. Tunnels lining are formed with precast concrete segments joined together with bolts and grouting behind to complete the circular inner face of the tunnel. With depth, the pressure of water increases greatly. No matter how effective the water proofing is, water will still find its way in between the segments joints or bolt holes forming efflorescence over time since ground water contains calcium carbonate after seeping through lime or concrete. However, current water proofing technology and material have mitigated the severity of the water seepage in tunnels.
Scratch Marks on Curtain Wall Aluminum Frame
The scratch marks could be caused by sharp metal object during the finishing and handing over of the project by the main contractor or during its normal operation.
Prior to the interior fit out works, a Pre Condition survey has to be carried out to record the existing conditions of the aluminum frames and glass panels so as to avoid future disputes or claims.
Our Reports
Industry Standard Reports
Reporting Methods
The Survey Report will consist of Introductory of Why the Pre-Condition / Pre-Construction Survey is required, methodological of the Survey, Site Plan of the Project Site and the Neighbouring Properties Surveyed, Definition of the Cracks, Colour Photographs of the Existing Condition of the Properties including the Defects, Description of the Defects.
Copies for Main Contractor
The Survey Report will be printed in Colour and Ring Binded with the Photographs in 4R size. The Contractor will received 2 Sets of the Printed Survey Reports, 1 Set of PDF Formatted Report in CDRom and upon request a softcopy of the PDF Formatted Report by File Transfer through Email or Cloud Transfer.
Owners / Stakeholders
The Owners / Stakeholders will also receive 1 Set of the extracted Survey Report in Printed Colour and Ring Binded of their concerned properties. The Pre-Condition / Pre-Construction Survey Report will be handed over to the Owners / Stakeholders by the Contractor.
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