Mastic Sealant | Mastic

Mastic sealants are essential for both construction and DIY projects, providing flexible and durable sealing solutions for a wide variety of applications. Whether you're working on sealing gaps, ensuring waterproofing, or securing joints, mastic products offer reliable performance across different surfaces and environments. At Build4Less, we provide a wide range of mastic sealants designed to meet the specific needs of every project.

What is Mastic Sealant?

A mastic sealant is a flexible, rubber-like material used to seal joints and gaps in various materials such as wood, metal, concrete, and glass. The versatility of mastic makes it popular in construction for sealing windows, doors, roofs, and gutters. Unlike rigid sealants, mastic sealants retain their flexibility after curing, allowing for movement without compromising the seal.

Types of Mastic Sealants Insulation Available

General Purpose Mastic Sealants

For everyday sealing tasks, general-purpose mastic sealants are the most versatile option. These sealants are suitable for both indoor and outdoor use, offering flexibility and durability in various conditions. They are commonly used for sealing around windows, doors, and even guttering. A popular product in this category is the Everflex 115 General Purpose Mastic by EVERBUILD.

Everflex 115 General Purpose Mastic by EVERBUILD

The Everflex 115 General Purpose Mastic is designed to handle a broad range of sealing and bonding tasks. Its versatility makes it ideal for use around windows, doors, and roof gutters. This mastic is easy to apply and can be used both indoors and outdoors, providing a reliable seal that stands up to different environmental conditions. It’s a fantastic all-around sealant for most sealing needs.

DPC (Damp Proof Course) Mastic Sealants

When working on projects that involve damp proofing, it’s essential to choose a mastic sealant specifically designed for moisture resistance. DPC mastic sealants are commonly used in construction to prevent water from penetrating walls, foundations, or basements. One of the best products in this category is the IKO Hyload DPC Mastic.

IKO Hyload DPC Mastic

The IKO Hyload DPC Mastic is specially formulated for damp proofing applications. This mastic is perfect for creating a moisture-resistant barrier in areas prone to dampness or water exposure, such as basements and foundations. It’s also ideal for external walls where protection against moisture is critical. Its high level of moisture resistance makes it a go-to choice for contractors and DIY enthusiasts working on projects that demand a robust waterproof seal.

Bitumen-Based Mastic Sealants

Bitumen-based mastic sealants are highly effective for tasks requiring strong waterproofing and sealing in areas subject to extreme weather conditions. These sealants are typically used in roofing, where durability and weather resistance are vital. Bitumen mastic sealants can also be used for repairing cracks in asphalt surfaces. ROOFTEC offers a reliable product in this category: Bitumen Mastic.

Bitumen Mastic by ROOFTEC

The Bitumen Mastic by ROOFTEC is ideal for waterproofing and roofing applications. This mastic is specifically designed to create strong, waterproof seals in roof joints and cracks. It is also useful for repairs on asphalt surfaces. Its ability to withstand extreme weather conditions makes it the perfect sealant for outdoor applications that demand extra resilience.

Selecting the Right Mastic Sealant

Choosing the right mastic sealant depends on the nature of your project. Different types of sealants are formulated for specific applications, and using the right product ensures a long-lasting, effective seal. Below are key considerations when selecting a mastic sealant:

• General Purpose Sealing: For general sealing tasks, such as sealing gaps around windows, doors, and guttering, opt for a general-purpose mastic sealant like the Everflex 115. This sealant is perfect for everyday tasks where flexibility and durability are essential.
• Damp Proofing: If your project involves damp proofing, such as in basements, foundations, or external walls, select a DPC mastic sealant like the IKO Hyload DPC Mastic. This product offers superior moisture resistance, ensuring your project remains free from damp-related issues.
• Roofing and Waterproofing: For roofing and waterproofing applications, where strength and weather resistance are critical, choose a bitumen-based mastic sealant. The Bitumen Mastic by ROOFTEC is designed to withstand harsh weather conditions and provide strong, durable seals on roof joints and cracks.

Why Choose Mastic Sealants from Build4Less?

• Unmatched Durability & Flexibility: Our mastic sealants maintain elasticity under extreme temperature changes and adhere firmly to a variety of surfaces—metal, concrete, brick, PVC—ensuring cracks and gaps stay sealed for years.
• Weather & Water Resistance:  Ideal for interior and exterior applications, they form a watertight barrier against rain, humidity, and freeze-thaw cycles—perfect for windows, doors, roofs, and joints.
• Easy Application & Low VOC: Designed for both pros and DIYers, our sealants come in easy-to-use cartridges that bond quickly with minimal shrinkage and boast low volatile organic compounds (VOCs) for a safer environment.
• Versatile Applications: Whether you're sealing joints, filling channels, bonding insulation boards, or closing up pipe entries, our mastic sealants offer universal solutions with outstanding compatibility.

Benefits of Mastic Sealant

• Elasticity & Flexibility: Ideal for dynamic joints that experience expansion or movement over time.
• Weatherproof Performance: Protects against moisture, wind, dust, and UV exposure—suitable for outdoor use.
• Sound Insulation: Acoustic-grade variants help reduce sound transmission through walls and partitions.
• Fire Protection: Fire-rated sealants expand in high temperatures to prevent fire and smoke spread.
• Easy Application: Comes in cartridge form for clean, controlled application using a standard caulking gun.
• Paintable & Durable: Once cured, most mastic sealants can be painted to match surrounding finishes.

Applications of Mastic Sealant

• Construction & Building Joints: Around windows, doors, expansion joints, and pipe entries.
• Roofing & Flashing: Sealing overlaps, gutters, cracks and joints in roofing materials.
• Bathrooms & Kitchens: Filling seams around sinks, tubs, and tiles to prevent water ingress.
• Fire-Rated Installations: Around cable trays, ducts, and fire doors in commercial buildings.
• Drywall & Partitioning: Sealing gaps in plasterboard and stud walls for acoustic integrity.
• Glass & Metal Bonding: Transparent mastic is perfect for discreet sealing in glass-to-glass and glass-to-metal joints.

 Why Choose Build4Less for Mastic Sealants?

• Trusted Quality Brands: We only stock reliable, trade-approved mastic products suitable for domestic and professional use.
• Wide Range of Options: From clear to black, acoustic to fire-rated, our collection covers every application need.
• Competitive Pricing: Get excellent value on single cartridges or bulk quantities with no compromise on quality.
• Expert Support: Our experienced team is available to help you select the right sealant for your project requirements.
• Fast UK Delivery: Nationwide delivery direct to your site or door, ensuring you stay on schedule.

At Build4Less, our mastic sealant products are designed to tackle a wide range of roofing, insulation, and pipe sealing tasks, whether you're working on a new build, refurbishment, or routine maintenance. From DPC mastic and fire mastic to intumescent sealants and cold-applied solutions, our range supports both commercial contractors and DIY users looking to fix cracks, seal joints, or secure pipe insulation. Our building mastic and acrylic sealant options offer excellent adhesion to common construction surfaces like PVC, asphalt, and metal, with hot melt and mastic asphalt choices available for specialist projects. Whether you need a mastic product for roofing, general sealing, or decorative purposes, we’ve got the tools and accessories to get the job done right, delivering performance you can count on with every application.