Concrete Hammer Test: Why SLF Does Not Always Mean Dismantling

One point needs to be clarified first: the term "hammer test" does not appear in PP 16/2021. The regulation recognizes the method category — "non-destructive testing". Hammer test (also known as a Schmidt hammer) is the field-practice term for a tool commonly used to apply this method — including in JKK's own practice, where we routinely conduct hammer tests and document the results in a hammer test report: the tool lightly impacts the concrete surface, then its rebound value is read as an indicator of the concrete quality at that point — without dismantling the structural element.

The legal basis is clearly regulated. PP 16/2021 Pasal 205 paragraph (5) states that a physical building inspection includes "a. visual inspection; b. non-destructive testing; and/or c. destructive testing". The hammer test falls within the non-destructive testing category — a method that the regulation positions as an option to be considered before methods that cause damage.

A hammer test is not a standalone inspection. It is one component in a broader series of structural system inspections. PP 16/2021 Pasal 220 paragraph (3) details the elements of a structural system inspection, including letter d: an indication of concrete quality using non-destructive testing methods — complementing other elements such as visual observation, dimensional measurement, and checking whether actual conditions conform to the as-built drawing.

This means that hammer test results are always interpreted alongside other data, not used alone as a verdict. Pasal 205 paragraph (6) even identifies the as-built drawing from the Owner, non-destructive testing equipment, and destructive testing equipment as inspection aids that complement one another.

Unlike non-destructive testing, destructive testing removes a small portion of a structural element for further examination, so it does cause damage, although on a limited scale. PP 16/2021 Pasal 220 paragraph (4) letter a states that the Pengkaji Teknis may add destructive equipment methods if necessary.

The important point is that this Pasal frames destructive testing as a method that may be added if necessary, without specifying criteria for when it becomes mandatory. The Technical Standards for certain building types may still require further inspection. Therefore, the claim that "certain buildings will definitely be dismantled" — or, conversely, definitely will not — cannot be answered in general without first examining their actual condition.

Structural inspection, including the hammer test, is only one part of a much broader functional suitability evaluation. Safety, health, comfort, and convenience are also assessed before a building is declared fit for function — the full scope is discussed in the four-pillar building functional suitability checklist.

Because the scope is broad, the result from a single measuring tool is never the sole determinant of SLF approval. The earlier the building's condition is inspected, the greater the opportunity for the owner to address findings before the legalization process enters its final stage. If you would like to understand your building's structural condition before applying for SLF, the JKK team can help conduct an initial assessment so the inspection can proceed in a more focused manner.