Are you struggling with ongoing roof leaks, damp basements, or structural maintenance issues? Bitumen sheets might be the best resolution to these problems. This blog aims to have a quick overview of bitumen sheets, how they are made, their uses, their benefits, and how to install them for dry, strong, and waterproof building projects.
What are Bitumen Membrane Sheets?
Bitumen membranes, often known as bitumen membrane sheets, have been a game-changer in the construction materials sector. They serve as an essential waterproofing component, creating a tight seal that safeguards buildings against moisture and leaks, consequently preserving the structural integrity of the buildings.
How are Bitumen Membrane Sheets Made?
Bitumen sheets are made from a dense, tar-like substance extracted from crude oil. By ingeniously amalgamating this bitumen with various modifiers and additives and, depending on the necessity, resilient fibres like polyester or fibreglass, we attain a robust, flexible and waterproof sheet. A meticulous process of heating and blending produces this potent material.
Polymer Modified Bitumen Sheets (PMBS) is an array of roofing and waterproofing materials fabricated by integrating a polymer (synthetic rubber or plastic) into the asphalt (bitumen) during the manufacturing process. PMBS is commonly referred to as a “mod bit” in the construction industry.
The primary distinction between conventional bitumen and polymer-modified bitumen is their composition and properties. Ordinary bitumen is essentially unmodified asphalt; however, polymer-modified bitumen is asphalt that has been “reformed” with the addition of synthetic rubber or plastic.
This modification amplifies the properties of bitumen, conferring additional advantages such as advanced durability, resistance to high temperatures and ageing, and superior adhesive properties. As a result, due to its higher durability and tolerance against environmental conditions, PMBS is often chosen more.
Different Types of Bitumen Membrane Sheets
Bitumen membrane sheets are available in a range of options, such as Atactic Polypropylene (APP), Styrene-Butadiene-Styrene (SBS), and Elastomeric bitumen sheets. Each variant possesses unique attributes and is formulated for specific uses, implying that it’s important to choose the correct sheet type for your waterproofing project to be successful.
Structure and Components of Bitumen Sheets
Each bitumen sheet comprises multiple layers, each fulfilling a particular function. Cohesively, they create a robust barrier against water infiltration and environmental stressors, denoting why bitumen sheets have become a preferred choice for a range of waterproofing applications.
- Bitumen Impregnation Layer: The central part of the structure ensures water impermeability by sealing leaks and thwarting water damage.
- Reinforcement Scrim: Positioned inside the bitumen layer, this section fortifies the membrane and preserves its integrity by resisting deformation and deterioration over time.
- Protective Top Layer: Being the external layer, it safeguards the sheet from environmental factors like harsh weather conditions and UV damage.
How to Select the Correct Bitumen Sheet?
When choosing the most suitable bitumen membrane sheet for your requirements, factors such as intended usage, regional weather conditions, and budget come into play. Remember, choosing the right type of bitumen sheet is essential for successful waterproofing projects.
| Type of Bitumen Sheet | Key Characteristics | Recommended Uses |
| APP Bitumen | Offers superior flexibility and UV resistance. | Suitable for roofing, terraces, and decks. |
| SBS Bitumen | Provides high elasticity and cold resistance. | Best for flat roofs, foundation waterproofing. |
| Elastomeric Bitumen | High tensile strength and elongation capabilities. | Perfect for waterproofing ponds, fountains, and tanks. |
Advantages of Bitumen Sheets
Bitumen sheets hold numerous advantages over other waterproofing materials, making them a popular choice for construction projects. Some key benefits include:
- Superlative Waterproofing: Bitumen sheets provide excellent defence against water leakage, assisting in maintaining the structural integrity of buildings for an extended duration.
- Exceptional Durability: Due to their impressive resistance to UV radiation, temperature, and chemicals, bitumen sheets contribute to long-lasting structures with reduced maintenance expenses.
- Longevity and Low Maintenance: Bitumen sheets require minimal upkeep, making them a practical and cost-efficient solution for construction projects.
- Ease of Installation and Flexibility: Bitumen sheets are renowned for their easy installation and can be attached using various methods—torch-on or self-adhesive—rendering them extremely flexible.
In short, bitumen sheets are better than traditional materials such as asphalt or PVC membranes in terms of waterproofing efficiency and efficacy.
Also Read: Importance of Ductility in Bitumen
Environmental Impact of Bitumen Sheets
Bitumen sheets have eco-friendly properties due to their recyclability. At the end of their life, these materials can be reclaimed and used in road construction projects or incorporated into new bitumen membranes. By promoting recycling, bitumen sheets contribute to resource conservation and minimise environmental waste.
Moreover, bitumen sheets increase building insulation, leading to reduced operational energy costs and a smaller carbon footprint.
Bitumen Sheet vs. Other Waterproofing Solutions
How do bitumen sheets measure up against other waterproofing materials available on the market?
- PVC (Polyvinyl Chloride) Membranes: While PVC membranes deliver excellent waterproofing, they lack some advantages of bitumen sheets, such as environmental sustainability and ease of installation.
- Liquid Waterproofing Membranes: These solutions have certain limitations, including sensitivity to weather during the curing process and often need additional layers for optimum performance.
Compared to various sealing solutions, bitumen sheets stand out for their durability, simplicity of installation and respect for the environment.
Also Read: Key Differences Between Bitumen and Asphalt
Installation Tips for Bitumen Sheets
The effectiveness of bitumen sheets largely depends on correct installation. Proper installation ensures a waterproof, long-lasting, and durable roofing solution. Ensure a clean, even surface, select the suitable fixation method, and meticulously seal corners and joints. Follow these steps for efficient installation:
1. Surface Preparation
- Inspect your roof surface for any defects or irregularities; repair any damages before starting the installation process.
- Clean your roof surface by removing all dust, debris, and dirt to ensure proper adhesion.
- Before proceeding to the next step, ensure that the surface is dry and free from humidity.
2. Choosing the Fixation Method
- There are three main fixation methods for bitumen sheets: torch-on, self-adhesive, and cold adhesive. Choose the method that best suits your application and environment requirements.
3. Sheet Application
- Start by laying the bitumen sheets from the lowest point of the roof, working up towards the ridge. Ensure proper alignment of the bitumen sheets by following the manufacturer’s recommended overlap distances and guidelines.
- If using the torch-on method, heat the underside of the bitumen sheet and the surface simultaneously as you apply them.
- For self-adhesive and cold adhesive methods, ensure proper pressure is applied to the sheets to activate the adhesive and prevent any bubbles.
4. Sealing Corners and Joints
- Use a separate, compatible bitumen material for sealing corners and joints to ensure a watertight seal.
- Apply a sufficient amount of the sealing material on the overlapping areas, and use a hot-air gun or torch for heating the material if needed.
- Press the overlaps with a hand roller or a similar tool to create a secure bond.
5. Final Inspections
- Inspect the entire installation for any gaps, defects, or improperly sealed areas. Fill any gaps or reseal as needed.
- Make sure all overlaps, edges, and corners are secured and watertight.
Remember, safety is crucial during the installation process, particularly when utilising the torch-on method. Make sure to use appropriate safety equipment, such as gloves, goggles, and a fire extinguisher. Employ proper ventilation, follow manufacturer recommendations, and, if feasible, seek expert supervision.
Also Read: What is Bitumen Paint?
Final Thoughts
Bitumen sheets are a strong, durable, and highly effective waterproofing solution. By selecting the right type and installing it correctly, you can protect your structure from potential water damage and ensure lasting results.