Finding and sampling asbestos

Originally there were three types of survey, types 1, 2 and 3. The details and distinctions for each were set out in MDHS (Methods of Determining Hazardous Substances) 100 published by the HSE. This was superseded in January 2010 by Asbestos: The survey guide, which consolidated these into two different types, according to their purpose.

(1) Management survey

This is for the management of ACMs during the normal use and occupancy of the property, to meet the requirements of regulation 4 of CAR 2012 in respect of non-domestic buildings.

The asbestos surveyor, using his or her knowledge and experience searches areas where asbestos might have been installed and identifies materials which the surveyor suspects may contain asbestos in one form or another. The assessment is made by a process of elimination, considering whether a material or component might reasonably contain asbestos.

Where appropriate, samples are taken and analysed, by an accredited laboratory, to prove or disprove the surveyor's presumption that a material may contain asbestos.

In situations where it may not be appropriate to take samples at that time (e.g. listed buildings and where there is no reasonable evidence - physically or historically - to the contrary), the surveyor must presume that it does contain asbestos material until proven otherwise.

Where possible, the degree of presumption should also be qualified according to the inspector's confidence, using the phrase 'strongly suspect' (e.g. corrugated roof sheets installed before 1999).

Where materials or components appear physically similar in all respects, for the purposes of this type of survey, it is reasonable to conclude that they are the same.

This type of survey is, by its very nature, likely to be pessimistic and err on the side of caution.

(2) Refurbishment and demolition survey

This survey is required when building works are proposed that might disturb forms of construction and/or components, the age and composition of which are not known with any degree of certainty and which may thus expose the workers or occupants to uncontrolled release of asbestos fibres.

Such works include demolition, refurbishment and to a lesser extent redecoration, and the survey is confined to those areas that will be affected by the works.

This involves invasive investigation, forming holes in or removing layers of the construction to reveal the form of construction and concealed materials or components often significantly damaging the finishes, fixtures and fittings.

In certain circumstances, it may not be feasible or practicable to complete the investigation at one time and a number of return visits may be necessary to site to suit the programme for opening up.

See section 8 of the Asbestos guidance note.