Flashing for waterproofing

When waterproofing a roof, it’s crucial that it’s completely watertight, and the most challenging part of the process is dealing with critical details.

Detail areas are critical points. On the one hand, they are more challenging to waterproof, as they are often irregular, have complex shapes, or may be composed of multiple materials. On the other hand, they are subject to structural movement, and if the waterproofing membrane used is not prepared or adequately reinforced, they could lead to leaks.

These areas are very difficult to waterproof with traditional sheeting systems. Likewise, poor waterproofing of detail areas jeopardizes the roof’s watertightness and, consequently, its structural integrity and durability. Therefore, it is generally more reliable to waterproof these areas with high-performance liquid products.

The importance of flashing for waterproofing detail areas

Waterproofing unique points or detail areas is the most challenging part of the roof waterproofing process, especially with traditional sheeting systems.

Proper waterproofing with a polyurethane membrane ensures long-term watertightness.

These include, among others, detail areas such as:

Roof drains and scuppers
Perimeters and other vertical-horizontal surface junctions, such as chimney bases on roofs
Joints
Protruding elements, downspouts, and ventilation ducts that penetrate the waterproofing layer
Skylights and other openings

Problems arising from failure to apply a flashing system for critical points

Detail areas are the most critical points where problems can arise and spread to the rest of the roof, for example:

Leaks
Structural damage
Moisture
Deterioration of finishes

To ensure structural stability and reduce repair costs, proper waterproofing is required not only for the horizontal surface but also for the entire perimeter of the roof and any detail areas.

To do this, it’s important to have a roof waterproofing membrane like DT Flash. DT Flash is a thixotropic, weather-resistant membrane developed as a system compatible with traditional sheets (asphalt felt, etc.) for waterproofing the most challenging areas.

Advantages of using a waterproofing membrane for detail areas

Polyurethane membrane waterproofing:

It is a fully bonded system that easily conforms to any shape in detail areas, which are challenging for traditional systems.
It is compatible with a wide range of materials (PVC, wood, metal, concrete, bituminous sheets, etc.).
It enables easy repairs to detail areas on roofs without the need for a flame or welding tools, making it a reliable and safe alternative.
It’s quick and easy to apply manually, cold, using a roller.

Additionally, we recommend that, whenever possible, you opt for reinforced systems. These not only offer greater resistance to structural movement but also ensure the membrane maintains its proper thickness.

How to use flashing for waterproofing at critical points

To seal critical points, the substrate must be free of dust, moss, grease, oil, or any other contaminants that could compromise the membrane’s adhesion to the substrate.

The DT Flash polyurethane membrane is ready to apply with a roller using the wet-on-wet system, with no waiting time between coats. It is fully reinforced with Eagle Matting, a fiberglass mesh that provides structural reinforcement and serves as a guide for applying the correct thickness.

The use of the DT Flash waterproofing membrane not only seals detail areas but also ensures the long-term watertightness of the entire roof.

Related applications and keywords: waterproofing crawl spaces.

Flashing projects for unique points

Waterproofing of drains

Waterproofing of curbs

Corner waterproofing

Perimeter waterproofing in detail

Projects completed with:

DT FLASH, a state-of-the-art single-component PU resin, is designed for waterproofing perimeters and detail areas that are often challenging to seal with traditional membranes.

Flashing for waterproofing