Who pays to repair spalling concrete in an HDB flat?
Flat owners are responsible for the interior of their flats, including spalling concrete. MND has stated that for spalling after the defects liability period, owners can ask for help under HDB's Goodwill Repair Assistance scheme, where HDB arranges the repair and co-pays 50% of the cost. Where a block undergoes the Home Improvement Programme, repair of spalling concrete and structural cracks is an essential improvement fully funded by the Government for Singapore Citizens.
From the RRD Field Guide, checked against the sources cited in Concrete Spalling in Singapore: Causes, Risks, Repair Methods and Who Must Fix It. General information, not advice for your project.
The fuller picture
Spalling concrete is concrete cover cracking and breaking away because the steel reinforcement inside has corroded, usually after carbonation or chlorides destroy the steel's natural protection. Small patches can be repaired by removing loose concrete, cleaning and priming the steel and patching with polymer-modified mortar. Extensive spalling, beams, columns or cantilevers need a Professional Engineer. Owners repair inside HDB flats; MCSTs repair common property.