Bitumen Mastic Sealant

Bitumen Mastic Sealant is a high-performance elastomeric sealant or joint-treatment system designed to accommodate joint expansion, contraction, and shear movements in building facades, pavements, and containment structures. Formulated for excellent weatherability, it remains flexible and maintains an impermeable seal against water, air, and chemical ingress.

Product Overview

Bitumen Mastic Sealant belongs to the Sealants & Joint Treatment family. It is intended for membrane terminations, roof flashings, below-grade details and utility joints. Final product selection must account for substrate condition, exposure, application method and compatibility with adjoining layers. Bitumen Mastic Sealant is a high-performance elastomeric sealant or joint-treatment system designed to accommodate joint expansion, contraction, and shear movements in building facades, pavements, and containment structures. Formulated for excellent weatherability, it remains flexible and maintains an impermeable seal against water, air, and chemical ingress.

Best-fit Applications

• Membrane terminations
• Roof flashings
• Below-grade details
• Utility joints

Technical Benefits

• Simple cold application
• Compatible with selected bituminous systems
• Useful for local waterproofing details

Technical & Performance Specifications

Physical Property	Declared Performance Value	Test Standard
Movement Accommodation	±25% to ±50%	ASTM C719
Adhesion to Substrates	> 1.5 N/mm²	ASTM C794
Shore A Hardness	25 - 35 (Flexible jointing)	ASTM C661
Skin Time	30 - 60 minutes	ASTM C679
Curing Rate	Approx. 2-3 mm per 24 hours	at 23°C / 50% RH
Elastic Recovery	> 85%	ASTM C920

Technical Datasheet Locked

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Application Guidelines & Installation Method

Step 1: For sealants, clean and dry the joint; apply primer where required; install the specified backer rod to the correct depth; apply continuously without air gaps; tool to a smooth finish; then allow adequate curing and protect from water, traffic and damage.

Step 2: Install filler boards accurately at movement joints and prevent displacement during concrete works.

Step 3: Install backing rods continuously at the specified depth, without gaps or stretching, using the correct size to prevent three-sided adhesion.

Standard Compliance

Conforms to ASTM, BS EN, and local municipality green building regulations. Verified through independent laboratory testing and certified project listings.

Products

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Bitumen Mastic Sealants

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