PVC Waterproofing Solutions

GENERAL INFORMATION ABOUT PVC

PVC waterproofing utilizes flexible membranes made from polyvinyl chloride (PVC) to create a continuous, impermeable barrier against water.

The PVC membrane itself is inherently waterproof. When properly installed and seamed, it forms a monolithic layer that does not allow water to pass through.

Advantages include excellent flexibility, UV resistance, chemical resistance, ease of welding (thermally), long lifespan, and a relatively lightweight system.

Yes, there are reinforced and non-reinforced PVC membranes. Reinforced membranes contain a polyester or fiberglass scrim for increased strength and dimensional stability.

A well-installed PVC system can last 30-50 years or more, depending on the specific product, environmental conditions, and maintenance.

Applications of PVC Waterproofing

It’s widely used on flat roofs, green roofs, podium decks, balconies, basements, tunnels, water features, and retaining walls.

Yes, many PVC membranes are specifically formulated for exposed applications due to their excellent UV resistance.

Absolutely. PVC is a popular choice for green roofs due to its root resistance and durability. Some manufacturers offer specific root-resistant PVC membranes.

Yes, PVC can be used for both positive (exterior) and negative (interior) side waterproofing of basements, often as a tanking system.

In some cases, yes, after proper assessment and preparation of the existing substrate. Compatibility and stability of the underlying material are crucial.

Installation of PVC Waterproofing

PVC membranes are typically installed by mechanically fastening them to the substrate, ballasting them, or fully adhering them. Seams are then hot-air welded.

Hot-air welding uses specialized equipment to heat the overlapping edges of PVC membranes to a molten state, fusing them together to create a homogeneous, waterproof seam.

Generally, primers are not required for PVC membranes themselves, but they may be needed for certain adhesive applications or to prepare specific substrates.

The substrate must be clean, dry, smooth, and free of sharp protrusions, dust, and contaminants. A leveling screed or protection layer might be necessary.

Details are meticulously fabricated on-site using cut sections of PVC membrane and often pre-formed accessories, all hot-air welded to the main membrane.

Common thicknesses range from 1.2mm to 2.0mm, though thicker membranes are available for specific applications.

While possible, extreme cold can affect the flexibility of the membrane and the efficiency of hot-air welding. Manufacturers provide specific temperature guidelines.

Yes, hot-air welding machines, hand welders, rollers, and various hand tools are essential.

PVC waterproofing installation, especially the critical hot-air welding, requires specialized training and experience to ensure a watertight system. It is generally not recommended for DIY.

Drains designed for PVC systems have a PVC flange that can be directly hot-air welded to the main membrane, ensuring a seamless and watertight connection.

Performance & Maintenance of PVC

Yes, PVC membranes formulated for exposed applications contain UV stabilizers to resist degradation from sunlight.

PVC offers good resistance to a wide range of chemicals, including acids, alkalis, and oils, which makes it suitable for various industrial applications.

Specific PVC membranes are manufactured with root-resistant additives, making them ideal for green roof applications. Always check product specifications.

Small punctures or tears can be repaired by cleaning the area and hot-air welding a patch of new PVC membrane over the damaged spot.

Regular inspections (at least annually) to check for debris, damage, and clear drains. Cleaning the surface is generally recommended.

Modern PVC membranes are formulated with plasticizers that resist migration, reducing the risk of embrittlement over time, especially with proper UV protection.

Yes, some manufacturers have recycling programs for post-consumer and post-industrial PVC waste.

While PVC is waterproof, prolonged ponding water is generally undesirable on any flat roof system as it can accelerate dirt accumulation and put stress on the structure. Proper drainage is always key.

Poor installation (especially improper welds), substrate movement, damage during follow-on trades, and severe chemical exposure not suited for the membrane.

PVC membranes are typically self-extinguishing and achieve good fire ratings. Check specific product classifications for details.

Torch-On Waterproofing Solutions | General Information about Torch-On

Torch-On waterproofing refers to systems using modified bitumen membranes (APP or SBS) that are installed by heating the underside with a propane torch, causing the bitumen to melt and adhere to the substrate and subsequent layers.

The bitumen, when heated and adhered, forms a continuous, impermeable layer. The overlap seams are fully fused, creating a monolithic barrier.

Advantages include high puncture resistance, excellent adhesion to various substrates, robust performance, and a proven track record.

APP (Atactic Polypropylene) and SBS (Styrene Butadiene Styrene) are polymer modifiers added to bitumen. APP offers better UV resistance and higher temperature stability, while SBS provides greater flexibility and elasticity at low temperatures.

A well-installed Torch-On system can last 15-25 years, depending on the specific product, number of layers, environmental conditions, and maintenance.

Applications of Torch-On Waterproofing

It’s extensively used on flat roofs, podium decks, balconies, retaining walls, foundations, and in some cases, re-roofing applications.

Yes, many Torch-On membranes come with a mineral granule finish for UV protection and aesthetics, making them suitable for exposed roofs.

Yes, Torch-On is a robust option for green roofs, especially when paired with a root barrier layer.

Yes, it is often used for tanking basements, particularly on the positive (exterior) side.

Often, yes, depending on the condition and type of the existing roof. A proper assessment and preparation (e.g., removal of loose material, priming) are essential.

Installation of Torch-On Waterproofing

Rolls of modified bitumen membrane are unrolled, and the underside is heated with a torch, causing the bitumen to melt and bond to the substrate or the layer below. Overlaps are then similarly fused.

The propane torch melts the bitumen on the underside of the membrane, creating a molten pool that flows and adheres to the substrate, forming a strong, monolithic bond upon cooling.

Yes, a bitumen primer is almost always required on porous substrates (like concrete, screed) to ensure good adhesion of the Torch-On membrane.

The substrate must be clean, dry, smooth, structurally sound, and free of sharp edges. Any voids or cracks need to be filled.

Details are carefully cut and formed from the membrane, often with additional layers of reinforcement, and meticulously torched down to ensure watertightness.

Common thicknesses for single layers are 3mm or 4mm. Multi-layer systems can be thicker.

SBS-modified membranes offer better flexibility in colder temperatures than APP. However, extreme cold can still affect the material’s workability and adhesion.

Yes, propane torches, gas cylinders, rollers, safety equipment (gloves, fire extinguisher), and various hand tools are essential.

Torch-On installation involves an open flame and requires significant skill and safety precautions. It is highly recommended that only trained and experienced professionals perform this work due to fire risks and the complexity of achieving a watertight system.

Lap joints are crucial. They must be consistently heated and pressed to ensure a complete fusion of the bitumen, forming an uninterrupted waterproof barrier.

Performance & Maintenance of Torch-On

Unprotected bitumen is susceptible to UV degradation. Hence, exposed Torch-On membranes typically have a mineral granule surface to provide UV protection.

Torch-On membranes offer good resistance to many common chemicals but can be affected by certain solvents and petroleum-based products.

Standard Torch-On membranes are not inherently root-resistant. For green roof applications, a dedicated root barrier layer is usually installed above the Torch-On.

Small punctures or tears can be repaired by cleaning the area and torching down a patch of new membrane over the damaged spot, ensuring adequate overlap.

Regular inspections (at least annually) to check for debris, damage, blistering, and ensure drains are clear. Removing accumulated dirt and vegetation is important.

While modified bitumen membranes are designed for flexibility, extreme temperatures or prolonged exposure without proper protection can lead to some hardening over many years.

Recycling options for Torch-On membranes are limited due to the mixed nature of the material (bitumen, modifiers, reinforcement).

Similar to PVC, while Torch-On is waterproof, prolonged ponding water is generally not recommended as it can accelerate degradation over time and put stress on the system.

Improper torching (under- or over-torching), insufficient overlap, substrate movement, punctures from other trades, and lack of proper UV protection.

Torch-On membranes have specific fire ratings. While they are installed with a flame, the finished product typically meets fire safety standards.

Comparing PVC & Torch-On & Other FAQs

Generally, PVC membranes offer superior flexibility, especially at lower temperatures. SBS modified Torch-On offers good flexibility, but less than PVC.

Torch-On membranes, especially thicker ones, typically offer higher puncture resistance due to their mass and rubbery nature.

High-quality PVC has the edge in longevity under optimal conditions due to its inherent material stability.  PVC does not require any maintenance and has a life expectancy of 30 – 50 years whereas Torch-On waterproofing requires regular maintenance and has a much shorter life span.

Both are suitable. PVC is inherently UV resistant. Torch-On requires a mineral granule finish for UV protection. The choice often comes down to aesthetic preference and specific project requirements.

“Easier” is subjective. PVC requires specialized hot-air welding skills. Torch-On requires careful handling of open flames and expert torching techniques. Both require trained professionals.

Both have environmental considerations. PVC production can involve plasticizers and chlorine. Bitumen is a petroleum product. Recycling options vary. Assessing the overall lifecycle impact is complex.

While generally not on the same surface as a primary waterproof layer, they can be used in different areas of a complex structure. For instance, Torch-On on foundations and PVC on the roof.

Costs vary widely based on region, product quality, system complexity, and contractor. Generally, they can be in a similar range for quality systems, but PVC might be slightly higher for exposed applications.

Yes, other systems include liquid-applied membranes (polyurethane, acrylic), EPDM rubber membranes, TPO membranes, and built-up asphalt roofs.

Fire prevention (fire extinguisher, clear work area), proper ventilation, personal protective equipment (PPE), and adherence to manufacturer’s safety guidelines are paramount.

Electrical safety for welding equipment, proper ventilation for welding fumes, and general site safety practices.

Critically important. A well-prepared, stable, and clean substrate is fundamental to the performance and longevity of both PVC and Torch-On waterproofing systems.

Often chosen for complex geometries, highly flexible applications, green roofs (due to inherent root resistance in some types), or when a lightweight system is desired.

Often chosen for its robust nature, high puncture resistance, proven track record, or when budget might be a stronger factor for a traditional system.

Regardless of the chosen material (PVC or Torch-On), the most critical factor for success is professional, experienced installation by trained and certified applicators who adhere strictly to manufacturer specifications and best practices.