SikaProof® A+ 12 | FPO Waterproofing Membrane for Below-Grade Structures

15/07/2026

SikaProof® A+ 12 | FPO Waterproofing Membrane for Below-Grade Structures

SikaProof® A+ 12 | FPO Waterproofing Membrane for Below-Grade Structures

Pre-Applied Foundation and Basement Waterproofing System

Product Description

SikaProof® A+ 12 is a high-performance waterproofing membrane based on polyolefin (FPO) technology, specially developed for below-ground waterproofing applications such as foundations and reinforced concrete basement walls.

The system creates a mechanical and chemical bond with concrete, providing permanent adhesion between the membrane and the structure. This unique bonding technology prevents lateral water migration between the membrane and concrete, ensuring long-term protection against groundwater pressure.

Developed by Sika, a global manufacturer of construction chemical solutions, SikaProof® A+ 12 is a reliable waterproofing solution for reinforced concrete structures exposed to underground water and demanding environmental conditions.

Application Areas

SikaProof® A+ 12 is suitable for:

  • Basement structures and foundation walls
  • Underground reinforced concrete structures
  • Precast and cast-in-place concrete systems
  • Waterproofing and concrete protection applications in existing structures

It is especially preferred for projects where groundwater pressure and long-term waterproofing performance are critical.

Key Advantages of SikaProof® A+ 12

Dual Bonding Technology
Creates a strong mechanical and chemical bond with concrete, preventing water from spreading between the membrane and concrete surface. In case of local damage, water migration is significantly limited.

Flexible Application Options
Can be used as both:

  • Pre-applied waterproofing system before concrete casting
  • Post-applied waterproofing solution with suitable installation methods

High Durability Performance
Provides resistance against:

  • Groundwater pressure
  • Aggressive soil conditions
  • Environmental underground stresses

It also offers a tested radon barrier performance.

Fast and Easy Installation
Membrane joints can be sealed using cold-applied tapes or thermal welding methods, providing practical installation advantages.

UV and Weather Resistance
Provides temporary resistance against external environmental conditions during construction stages.

Crack Bridging Capability
Adapts to structural movements and helps maintain long-term waterproofing performance.

Certified Quality
CE marked and compliant with EN 13967:2012 requirements.

Technical Specifications

Total Thickness: 1.75 mm
Membrane Thickness: 1.20 mm

Roll Width Options:

  • 1.00 m
  • 2.00 m

Roll Length: 20 m

Colors:

  • Membrane layer: Light yellow
  • Bonding layer: Grey

Application Temperature: +5 °C to +45 °C
Substrate Temperature: +5 °C to +60 °C

Why Choose SikaProof® A+ 12?

Below-grade waterproofing is one of the most difficult construction elements to repair after completion. Traditional non-adhered membranes may allow water to travel between the membrane and concrete when damage occurs.

Unlike conventional systems, SikaProof® A+ 12 forms a complete bond with concrete, providing a safer and more durable waterproofing solution.

The system is particularly suitable for:

  • Projects exposed to groundwater pressure
  • Structures requiring radon protection
  • Buildings where long service life is a priority
  • Underground reinforced concrete applications

Its advanced bonding technology, installation flexibility, and certified performance make it an effective solution for modern waterproofing projects.

Frequently Asked Questions (FAQ)

Where is SikaProof® A+ 12 used?

It is used in basement structures, foundation walls, underground concrete structures, and reinforced concrete systems exposed to water pressure.

What does dual bonding technology provide?

It creates both mechanical and chemical adhesion between the membrane and concrete, reducing the risk of lateral water movement.

Does SikaProof® A+ 12 provide radon protection?

Yes. The system has tested radon barrier properties and can be used in projects where radon protection is required.

How is SikaProof® A+ 12 installed?

The membrane can be installed before concrete casting or applied afterward with suitable system solutions. Joints are sealed using waterproofing tapes or thermal welding methods.

What are the available roll dimensions?

The membrane is supplied in 1 m or 2 m wide rolls with a standard length of 20 m.