What Are The Related Accessories For Gas Barrier Membranes?

When constructing buildings, particularly on sites with harmful gases like radon, methane, or carbon dioxide, the installation of gas barrier membranes is essential. These membranes prevent dangerous gases from seeping into the building, maintaining a safe environment for occupants. However, for effective operation, these membranes need specific accessories that uphold their integrity and performance. Let’s explore these essential accessories in straightforward terms.

Key Accessories for Gas Barrier Membranes

Sealing and Bonding Accessories

Gas Barrier Tapes

What Are They?

Gas barrier tapes are ultra-strong adhesives used to seal overlaps and joints in gas barrier membranes during construction work. They resemble wide, durable sticky tapes but are specially designed to resist environmental factors like moisture and gas pressure. Contractors use them to join membrane sheets seamlessly, even on uneven or rough building surfaces.

Why Are They Important?

Gas tapes form a continuous, sealed barrier that blocks harmful ground gases from entering buildings. If omitted or poorly applied, small gaps may appear, allowing dangerous gases to seep indoors. These tapes are vital for preventing leaks at critical points, particularly where membrane sheets overlap or meet structural elements like walls and columns.

Types of Gas Barrier Tapes

• Double-sided Tape: Applied between two layers of membrane to bond them securely, even in vertical positions. Installers press the layers together firmly to avoid air bubbles.

• Single-sided Foil Tape: Used to seal the exposed outer edge of overlaps and to reinforce the strength of the joint.

  
  

Additional Tips for Using Gas Tapes

• Clean the membrane surface before applying the tape for maximum adhesive strength.

• Use a pressure roller to press the tape down firmly, eliminating trapped air.

• Apply primer if the surface is dusty, damp, or porous to improve adhesion.

• Store the tape in cool, dry conditions to prevent degradation.

  
  

Gas Barrier Top Hats

What Are They?

Gas barrier top hats are pre-moulded, dome-shaped accessories designed to fit snugly around service penetrations like pipes or ducts. They ensure that gas barrier membranes remain sealed. Installers position them over the pipe and fix them to the membrane using gas-resistant adhesive or tape.

Why Are They Important?

Pipes, vents, and cables create potential leak points during construction. Top hats seal these gaps, creating an airtight barrier that prevents harmful gases from infiltrating buildings. Without a properly installed top hat, gas can bypass the membrane through these openings. Top hats also reduce the need for complex cutting, saving time and minimizing errors.

Installation Tips for Top Hats

• Choose the correct size for a snug, gap-free fit.

• Use gas-resistant tape or sealant around the flange where the top hat meets the membrane.

• Apply a primer if the surface is dusty or rough for better adhesion.

• Test the seal after installation to confirm it is airtight.

  
  

Gas Barrier Corner Units

What Are They?

Gas barrier corner units are pre-formed components designed to seal corners and complex junctions in gas barrier membranes installation, especially within building foundations. They fit neatly into tight angles or awkward transitions. Most corner units bond effectively with gas barrier membranes and are available in various configurations to accommodate different structural layouts.

Why Are They Important?

Corners are challenging to seal using only flat membrane sheets. Wrinkles and gaps can form, creating pathways for gases. Corner units eliminate this risk by offering a ready-to-fit, airtight solution. Their use enhances consistency and reduces human error during installation.

Installation Tips for Corner Units

• Select internal or external corner units based on joint orientation.

• Prime both the membrane and corner area before installation to enhance adhesion.

• Seal edges with gas-proof tape for added security.

• Avoid stretching the membrane when connecting it to the corner unit.

  
  

Primer

Primer is a bonding agent applied before membranes or sealants to enhance their adhesion. It acts as a sticky base coat helping tapes and membranes grip tightly onto surfaces. Primers are quick-drying and formulated to work alongside gas-resistant products.

Why Is It Important?

Surfaces like concrete can weaken the bond between membranes. Primer fills imperfections and creates a tacky layer that improves adhesion, preventing lifting or peeling. It also extends the lifespan of the gas barrier system, ensuring continued efficacy.

Application Tips for Primer

• Clean the surface thoroughly before applying the primer.

• Stir well before use and apply an even coat.

• Allow the primer to dry until tacky before applying any tape.

• Follow the advised drying time on the product label.

  
  

Gas Barrier Jointing Strips

What Are They?

Gas barrier jointing strips are rigid strips designed to seal and reinforce overlaps between membrane sheets. They secure two sections through pressure and adhesion, adding an extra layer of protection.

Why Are They Important?

Seams are vulnerable points in any gas barrier. Even perfectly taped seams can deteriorate over time. Jointing strips provide crucial reinforcement, significantly reducing the risk of gas infiltration through overlaps.

Installation Tips for Jointing Strips

• Clean and dry the membrane surface before application.

• Apply even pressure along the strip for full contact.

• Use compatible adhesive for added security.

• Position the strips accurately to cover the joint area completely.

  
  

Gas Barrier Sealants

What Are They?

Gas barrier sealants are thick, flexible adhesives used to seal small gaps around gas barrier membranes. They are applied in areas where tape may not be effective, adhering to various materials while maintaining their flexibility.

Why Are They Important?

Even a small gap can allow harmful gases to enter. Sealants provide an airtight seal in complex areas, reinforcing weak points that are often overlooked during installation.

Where to Use Sealants

• Around top hats and pipe entries to block gas pathways.

• In corners, junctions, and detailing areas for a smooth seal.

• Beneath overlaps for double protection.

• Along perimeter edges where the membrane meets other structures.

  
  

Application Tips for Gas Sealants

• Clean the surface thoroughly.

• Cut the nozzle tip to suit the required bead size.

• Smooth the bead for a firm press into the gap.

• Allow adequate curing time before applying pressure.

  
  

Protection and Ventilation Accessories

Gas Barrier Protection Boards

Gas barrier protection boards are durable sheets installed over gas membranes, safeguarding them from construction damage. They act as protective armor against sharp tools, heavy machinery, and debris.

Why Are They Important?

Construction sites are high-traffic areas, making membranes vulnerable to damage. Protection boards help preserve membrane integrity during critical phases of construction, ensuring that the gas barrier remains effective.

Installation Tips for Protection Boards

• Lay protection boards immediately after membrane installation.

• Slightly overlap the boards to eliminate gaps.

• Use temporary fixings to hold boards in place in windy conditions.

  
  

Ventilation and Gas Extraction Systems

What Are They?

Ventilation and gas extraction systems are engineered solutions that safely divert harmful gases away from buildings. They include components like perforated pipes, vertical vents, and mechanical fans for active extraction.

Why Are They Important?

Gas membranes protect buildings but do not remove gas build-up. Without ventilation, harmful gases can accumulate, creating pressure that might compromise the membrane’s integrity. Ventilation alleviates this pressure, allowing gases to disperse safely.

Types of Ventilation Systems

• Passive Systems: Use natural airflow to disperse gases without electricity.

• Active Systems: Incorporate fans to actively extract gases.

• Radon Sumps: Collection chambers for targeted gas removal.

• Vent Mat Systems: Provide a continuous air path beneath membranes.

  
  

Installation Tips for Ventilation Systems

• Position vent pipes within gravel layers for maximum gas coverage.

• Ensure vent outlets terminate above ground level, away from air intakes.

• Use robust, perforated piping to prevent blockages.

• Regularly inspect and maintain these systems for continuous performance.

  
  

Conclusion

Gas barrier membranes alone cannot fully protect a building from harmful ground gases without the right supporting accessories. Components like tapes, top hats, corner units, sealants, and ventilation systems are essential for sealing potential weak points.

Each accessory significantly enhances the integrity of the system. Protection boards safeguard membranes from physical damage, while ventilation systems relieve gas build-up pressure. Omitting any components can lead to gas ingress and safety hazards. Always use high-quality, compatible products and follow proper installation procedures. A well-sealed gas protection system not only safeguards the structure but also protects its occupants. Be precise, seal every detail, and build confidence into your project from the ground up.

FAQs

Can I install gas barrier membranes and accessories myself?

Professional installation is highly recommended for correct sealing, proper detailing, and compliance with building regulations and safety standards.

Are accessories universally compatible with all gas membranes?

No. Accessories are not always interchangeable. Refer to the manufacturer’s guidelines before purchasing or installing components.

Is primer necessary for gas membrane installation?

Yes. Primer significantly improves adhesion on rough surfaces, preventing tape or membrane failure.

How long do these gas protection systems last?

When properly installed and protected, gas protection systems can last for decades, ensuring long-term safety.

Do gas protection systems require maintenance?

Yes. Periodic inspection is advisable, particularly for systems with mechanical components, to ensure continued performance and compliance.