Sealant & Caulking in Vancouver

High-Rise Sealant & Caulking Technical Specifications

In modern high-rise and commercial buildings, the joints between different envelope components—such as concrete panels, window frames, cladding sheets, and expansion joints—are the most vulnerable points for water ingress. These joints are filled with flexible joint sealants designed to absorb movement while maintaining a watertight barrier. However, UV exposure, temperature swings, and wind pressure cause sealants to dry out, lose elasticity, and split. Failed caulking is the leading cause of building envelope leaks. Allweathercoating provides professional sealant replacement using commercial-grade silicone and polyurethane systems.

Types of High-Performance Joint Sealants

We select joint sealants based on substrate composition, movement requirements, and exposure levels:

• Silicone Sealants (e.g., Dow Corning 790/795): The gold standard for high-rise glazing and window perimeters. Silicones offer outstanding UV resistance, remain flexible in temperatures from -40°C to 150°C, and carry movement capabilities of up to +100%/-50%. They have a lifespan of 20+ years.
• Polyurethane Sealants: Highly durable with excellent adhesion to concrete and masonry. Polyurethanes are paintable and ideal for tilt-up concrete wall joints and low-rise stucco perimeters. They typically last 7-10 years.
• Silyl-Terminated Polyethers (STPE): Hybrid sealants combining the paintability of polyurethane with the UV resistance of silicone, ideal for damp-substrate applications.

Our Technical Replacement Process

Simply applying new caulk over old, failed sealant is a temporary patch that will fail within months. We enforce a thorough multi-step replacement protocol:

• Complete Removal: Old sealant is mechanically cut out using specialized knives and detail blades down to the bare substrate.
• Joint Cleaning: Joint faces are ground or solvent-wiped to remove dust, old residue, and moisture. Proper sealant adhesion requires a clean, dry, solid surface.
• Backer Rod Installation: A closed-cell polyethylene foam backer rod is inserted into the joint. This controls sealant depth and prevents "three-sided adhesion" (sealant must only adhere to the two parallel joint sides to flex properly).
• Priming: Porous substrates (like concrete or brick) are primed if required by the manufacturer.
• Tooling: The sealant is applied with commercial sausage guns and tool-profiled to a concave shape, compressing it against the joint walls to ensure a permanent bond.

Joint Design and Movement Capabilities

Thermal expansion causes buildings to shift. Joint design must match the expected thermal expansion. Our technicians ensure that the width-to-depth ratio of all joints complies with ASTM C1193 guidelines (generally a 2:1 width-to-depth ratio), allowing the joint to stretch and compress without tearing away from the building envelope.