St John Primary Concrete Repairs – NATCEM® 35

Project – Concrete Repairs at St John Primary School
Product – NATCEM® 35
Contractor – Richardson & Starling

NATCEM® 35 was specified for a series of concrete repairs at St John Primary School in Barrhead, addressing deteriorated structural elements identified during a recent survey.

Project Background

The building, constructed primarily from reinforced concrete, had exhibited significant spalling and corrosion, particularly on exposed reinforcement areas across various elevations. Previous render repairs had de-bonded from the concrete substrate, further accelerating deterioration.

Cowal Design, tasked with designing the remedial works, highlighted the need for a high-performance repair mortar with minimal shrinkage, rapid setting properties, and exceptional durability. NATCEM® 35 was selected due to its proven ability to meet these stringent requirements without the need for additional primers.

Scope of Work

The works were conducted in two phases:

1. Phase 1 – Repairs to the rear elevation, addressing spalling on copes, beams, and lintels.
2. Phase 2 – Repairs to the left, right, and front elevations, including inaccessible areas for which allowances were made.

Key tasks included:

• Erecting tower scaffolding for safe access.
• Cutting out deteriorated concrete to expose reinforcement.
• Cleaning and assessing reinforcement for reuse or replacement using H8 U-bars and Hilti Hit Re300 resin.
• Applying NATCEM® 35 in layers, ensuring substrate saturation for optimal adhesion and performance.