Need for building Diagnostic

  1. Persistent Defects

• Most of cracks & deformations in buildings are minor & localized & could be rectified by regular maintenance .
• If the cracks & deformations persist in a manner that appears to worsen progressively or become widespread , a detailed building diagnostic assessment should be carried out to determine the cause of defects & to ensure long term serviceabiity of the building .

2. Ageing structure

• It may develop visually hidden defects such as carbornation of concrete & corrosion of steel reinforcement .
• It is advisale that old buildings be checked periodically to determine the presence & effects of these hidden defects .

3. Change of use or Rehabilitation

• A diagnostic assessment should be  considered for those buildings which have being rehabilitated or undergoing a change of use .
• An assessment will examine the suitability of the new usage , particularly with reference to the sufficiency of structure members to take the new loads .

4. Sale of property

• Whenever there is any reslae of a building , a diagnostic assessment could be started by the following interested parties :

- The prospective purchaser who needs to know the condition of the building  , house , factory , office or shop .
- The vendor in order to disclose to the purchaser the defects & their rectification , especially those works undertaken which are not available for inspection such as underpinning , alterations , damp-proofing or eradication of rof .
- The bank or financial institution that is processing the mortgage loan to the potential buyer .

5. Budgeting Maintenance Costs

• An assessment of the building will permit accurate budgeting of annual repairs & maintenance costs required as well as longer- term expenditure to preserve the building .
• THis is particulary important for older buildings where funds are difficult to secure .

6. Post - Crissis Assessment

• Severe events such as a fire or overloading can cause damage to structural members of the building .
• Therefore , it is necessary that an assessment of the structural integrity & safety of the building be conducted before any reinstatement work is done .

7. Satisfying statutory Requirements

• In many countries , mandatory inspection of certain types of buildings is required & the aim of such compulsory inspection is to ensure that the buildings are structurally sound & safe to be occupied .
• It is usual practice for commercial & industrial buildings to be subjected to more regular inspections compared to residential buildings .
• The scope of a survey required in all building diagnostic assessment is related to

-The nature of the defects
- The accuracy with which the cause of the defect need to be identified &
- The main reasons for wanting to know why the defect has occurred .

• At a simple level , the diagnosis may be based on a survey that consists no more than through visual inspection ( often called a reconnaissance survey ) .
• At extreme level , it may be necessary to undertake extensive opening up , site & laboratory tests & intensive data collection ( called  a detailed structural survey ) .
• Reconnaissance survey is the preliminary survey that enables the investigator to study the advantages & disadvanages of the variety of routes & determine which route is required .
• Maintenance personnel is the person who would notice defects during their routine duties & alert the building owner . THey also could make some preliminary assessment of the severity of the defects .
• For minor defects , a suitable contractor can be called to rectify the defects but for major or recurrent defects such as excessive conrete spalling , severe cracking or serious water seepage , an independent building consultant should be engaged .
• For architectural defects , the consultant could be a building surveyor , architect or engineer experienced in such works whereas a professional engineer should be engaged for structural defects .
• The consultant would prepare an assessment programme , conduct a building diagnosis and recommend necessary remedies . ( Refer Flow Chart )
• In architectural defects , te consultant could have basic instrucmentation to conduct the diagnosis but for structural defects , a diagnosis testing expert would usually be necessary to carry out test on the members as part of the diagnostic programme .
• Once data have been collected & collated a propert report should be drawn up for the owner .
• In most cases , the consultant 's service could be extended to include preparation of specifications & tender docuents , selection of repair contractors & supervisions & the repairs .