Bitumen-Based Waterproofing Applications

Bitumen-Based Waterproofing Applications

Bitumen-based waterproofing products are among the most effective solutions for protecting structures against damage caused by water and moisture. Applied with confidence in critical areas such as foundations, retaining walls and wet areas (bathrooms, kitchens, balconies and so on), they increase the durability of surfaces and provide long-lasting protection.

With over 25 years of experience in waterproofing and an expert staff, our company offers the highest quality standards in bitumen-based applications. While protecting your structures with the modern techniques and environmentally friendly products we use, we offer you economical and reliable solutions.

Advantages of Bitumen-Based Waterproofing Applications:

• Effective Protection: Prevents the damage caused by water and moisture in foundations, retaining walls and wet areas.
• Durability: Gives structures a long life and reduces maintenance costs.
• Flexibility: Easy to apply on various surfaces and conforms closely to them.
• Environmentally Friendly: Provides sustainable protection through the use of environmentally friendly materials.
• Economical Solution: A waterproofing method that is both budget-friendly and cost-reducing in the long term.

Our company develops solutions suited to the requirements of your projects in bitumen-based waterproofing and keeps quality at the forefront throughout the application process. You can benefit from our professional services to secure your structures against water and moisture.

Application Areas of Bitumen-Based Waterproofing

• Beneath foundations and on retaining walls — surfaces that remain below ground and cannot be reached later
• Terraces and pitched roofs — top coverings exposed to rain, snow and UV
• Surfaces in contact with soil on retaining walls and garden terraces
• Bridge and viaduct decks — the protective layer beneath the asphalt surfacing
• The outer faces of water tanks and pools, and tunnels and underpasses

Types of Bituminous Membrane and Application Techniques

SBS-Modified Sheets

Bitumen modified with styrene-butadiene-styrene retains its flexibility at low temperatures. It is preferred in cold climate regions and at details where movement is expected. The cold bending value is the most important parameter showing how the material behaves in winter conditions.

APP-Modified Sheets

Modified with atactic polypropylene, these sheets offer high temperature resistance and UV resistance. They are advantageous in hot climates and on roofs in direct sun. Because their flow point is high, the risk of softening in summer is low.

Torch-On (Flame) and Cold Application

In the torch-on method the underside of the sheet is melted with a flame and bonded to the surface; this is the most common and economical method. Where there is combustible insulation material or a timber deck, self-adhesive sheets or cold adhesives are used instead, eliminating the fire risk.

The Application Process

• 1. Surface preparation: The surface is cleaned, loose pieces are removed, and voids and cracks are filled with repair mortar. Internal corners are filleted and external corners rounded.
• 2. Priming: A bitumen-based primer is applied to bind the dust on the surface and increase the bond strength of the membrane. Membrane laying begins once the primer is completely dry.
• 3. Reinforcement of details: Additional reinforcing pieces are applied at outlet openings, pipe penetrations, corners and junctions. Most failures begin in these areas.
• 4. Laying the membrane: The rolls are laid perpendicular to the fall; transverse and longitudinal overlaps are left in accordance with the manufacturer's data and full adhesion is achieved. Bitumen bleeding out at the overlap edges is the sign of a complete bond.
• 5. Testing and protection: A flood test is carried out in suitable sections. The approved surface is protected against mechanical and UV effects with a protective screed, drainage board or gravel ballast.

Technical Notes and Standards

• Bituminous sheets used in roof waterproofing are covered by TS EN 13707, and foundation and damp barrier applications by TS EN 13969 .
• Applying two layers (cross-laid) instead of a single layer provides a significant margin of safety against overlap defects.
• If the membrane is to remain exposed, a mineral-surfaced type must be selected; bare bitumen ages rapidly under UV.
• Torch-on application carries a fire risk; a cold system should be preferred near combustible materials.

Frequently Asked Questions

How many years does a bituminous membrane last?

In protected foundation applications the service life is very long. On exposed terraces, however, periodic inspection is required because of UV, temperature differences and mechanical effects. Using a mineral-surfaced sheet, the correct fall and a working drainage system extend the life significantly.

Can a new membrane be applied over an old one?

If the existing covering is sound, fully bonded to the surface and not holding water, a second layer can be applied over it. However, if water is trapped underneath, or there is blistering or debonding, the old layer must be stripped; otherwise the trapped moisture will lift the new layer as well.

Should I choose SBS or APP?

The climate is the determining factor. SBS is more suitable in regions with low winter temperatures and at details subject to movement, and APP in hot regions with intense sun. Because flexibility matters at detail areas, SBS is preferred in most projects.

Blisters are forming beneath the membrane — what causes this?

The most common causes are a surface that is not sufficiently dry, laying the membrane before the primer has fully dried, and moisture trapped in the layer beneath. Water vapour expanding with temperature separates the membrane from the surface. To remedy this, the blistered area is opened up, dried and patched.