BC Building Products The Envelope Specialist

Synopsis: Discover how to choose the right silicone sealant for concrete, metal, and glass projects in Vancouver’s tough weather conditions — with practical tips from BC Building Products.

When working on building-envelope projects in Greater Vancouver and all of British Columbia, choosing the right sealant for concrete, metal, and glass surfaces can make the difference between a joint that lasts and one that fails too soon and costs a lot to fix. BC Building products (BCBP) is happy to give this complete guide to aid you on your journey as your trusted distributor of façade, waterproofing and envelope materials.

Why is it important to use the correct silicone sealant?

Silicone sealants are used a lot in facade, glazing, and structural-joint applications because they can work in a wide range of temperatures, withstand UV rays well, last a long time, and stick to a variety of surfaces (including masonry, concrete, glass, and metal) even when they move.

But not all silicones are the same. If you choose a sealant that doesn’t allow for enough mobility, doesn’t stick properly, uses the wrong sort of cure, or has chemistry that doesn’t work with the substrate, you could end up with cracks, stains, or water getting in. Studies suggest that proper specification and surface preparation are very important.

(Source-https://www.shinetsusilicone-global.com/catalog/pdf/FunctionalSealantsTechnicalManual_E.pdf?)

For builders in Vancouver’s rainy, unpredictable environment, it’s even more crucial to choose a sealant rated for wet, cold and exterior exposure, and to ensure installation conforms with best practice.

Important factors to think about when choosing silicone sealants

Before you choose a specific product, think about these things:

Accommodating movement

Thermal expansion and contraction, wind loads, settlement, or dynamic stresses can all cause joints between building components to shift. The sealant must be able to handle this movement without breaking. Many silicones are graded for their ability to expand and contract according to standards like ASTM C920.

For instance, metal-clad panels might expand and contract a lot, so a silicone with a low modulus (more mobility) is generally needed.

Adhesion and modulus

Low-modulus silicones relieve tension at the bond between the sealant and the substrate. This is especially useful when two different materials meet, such concrete and aluminium. High-modulus silicones might work better for joints that are more stiff, but they could also cause stress and de-bonding.

Also, sticking to the substrate is quite important. The substrate needs to be clean, sound, and suitable. Sometimes, especially on metals or coated surfaces, a primer is needed to make sure the adhesive is strong.

The way the cure works and the conditions around it

Acetoxy-cure or neutral-cure silicone sealants are available. Neutral-cure is better for metals (to avoid corrosion) and sensitive substrates.

Also think about the temperature, humidity, and curing time. In Vancouver, for example, the cold, damp mornings and low dew points might slow down the curing process.

Compatibility with the substrate and how it looks

Concrete, metal, and glass all have their own problems:

Concrete (which is porous and alkaline) could need to be primed or pre-treated.
Metal may have factory coatings, mill scale, or oils on its surface, therefore it’s important to prepare it well.
High-performance silicones that can handle bond lines, movement, and weathering may be needed for glass and structural glazing.
Also, things like the colour match, the polish of the tools, and the risk of staining on bright surfaces are important. Some silicones could leave a mark on porous material underneath.

Weatherproof and long-lasting

Sealants should stay sticky, flexible, and waterproof/airproof throughout the life of the design (20 years or more for modern silicones). The fact that Vancouver has UV, moisture, freeze-thaw cycles, and wind-driven rain shows how important it is to use high-quality sealants.

Advice for Vancouver projects that is specific to the substrate

Here’s how to use those standards in real life for concrete, metal, and glass surfaces in buildings in your area.

Joints in concrete

Before putting on the sealer, make sure the concrete is well cured, free of laitance, dust, and as dry as possible.
Choose a sealant with a low modulus and a good expansion/compression rating (±25% or higher) if the junction is a movement/control joint, like a precast panel joint or a slab contraction joint.
For the sealant to work as it should, think about the back-eroder (back-up rod) and the right joint shape (depth to width ratio).
Make sure the sealer is safe for concrete or that a compatible primer is utilised where it says to be.

Joints between metal and metal or metal and other materials

An elastomeric sealant with a lot of movement ability is good since metals expand and contract more than most other materials.
It’s important to prepare the surface by getting rid of oils, leftover materials from the fabrication process, and making sure it’s clean (for example, using an isopropyl alcohol wipe). You could also want to use a primer if you need to.
If there are metals present, choose a neutral-cure silicone to avoid corrosion problems.
When using aluminium composite panels, metal curtain walls, or cladding systems that are typical in Vancouver, check sure the sealant works with the panel coatings and that the sealant maker has tested how well it sticks to that surface.

Joints between glass and structure/glazing

You might need high-performance structural or weather-seal silicones for curtain walls, shopfronts, or insulating-glass units (IGUs). For instance, two-part structural silicones that fulfil ASTM C1184 or a similar standard.
Make sure the joint design includes “bite” (the width of the sealant interface on each substrate), “thickness” (the thickness of the sealant bead), and “movement capability.”
There should be no dirt or other substances on glass surfaces. Coatings or low-e glazing may influence adherence, so test if you’re not sure.
For outdoor projects that will be exposed to Vancouver’s rain, wind, and freeze-thaw cycles, make sure the sealant can withstand UV rays, dynamic movement, and the test of time.

Vancouver’s climate and things to think about when installing

Rain, moisture, and cool temperatures: When installing sealant, you should stay away from direct rain or heavy condensation while it cures. If joints are exposed to rain, think about putting up temporary cover.

Temperature changes: Vancouver has warm winters, but it gets cold and damp in the early morning, which slows down the cure. Use sealants that are rated for the conditions on the project site, and if the temperature is low, prepare for longer cure times.

Building envelope performance: Make sure that the sealant works with the flashing, vapour/air barriers, cladding and drainage systems as part of your façade system (via BCBP’s line of envelope solutions).

Logistics: BCBP has a “Caulking / Sealant” category on its website, so make sure to choose a product that is in stock and works well in your area.

Choosing and putting in silicone sealants

Before you compose your spec or place an order, use this checklist for specifications:

Define the substrate(s): concrete, metal, glass; list any coatings or possible pollutants.
Control/expansion, glazing, and cladding-panel interface are all types of joints.
What is the predicted movement? ± %? Choose the right class of sealant.
Pick the kind of sealant you want: one-component or two-component; neutral-cure or acetoxy; low or high modulus.
Check the manufacturer’s data sheet to make sure the adhesion/compatibility is correct. If the substrate is new to you, you should test it.
Check the colour, finish, and ability to be painted (most silicones can’t be painted).
Document that explains how to install a backing rod, how to use tools, and how to measure joint geometry (depth:width ratio).
Take into account the temperature, humidity, exposure to the weather, and cure time.
Check the warranty or performance rating: many sealants now come with long-term warranties if they are placed correctly.

Best ways to install

Use two cloths to clean the substrate well and get rid of any dust or loose particles.
If necessary, follow the manufacturer’s instructions for applying primer and let it dry before applying sealer.
Install the backing rod as needed and make sure the joint dimension is correct (don’t use beads that are too shallow or too deep).
Sealant should be applied in a continuous manner, and the bead should be tooled to the right concave finish. The masking tape should be taken off right away after tooling.
Don’t use too many tools (a bead that is too thin makes the job harder) or too much excess that is extruded.
Until the sealant has had enough time to dry, keep newly sealed joints safe from rain, injury, or movement.
Check the finished joints to make sure they are sticking together, are even, and don’t have any bubbles. Also, make sure the sealant is completely dry before putting any weight on it or exposing it to the elements.

Find the Right Silicone Sealant at BCBP Vancouver

We are more than just a supplier at BCBP; we are your building-envelope partner. We provide a wide choice of high-performance sealants in Surrey, BC (under the Caulking/Sealant product category). We also offer professional advice to help you choose the best system for your façade, glazing, or control joint application.

If you’re working on a high-rise curtain wall in downtown Vancouver or a multi-unit residential project on the North Shore, choosing the right silicone sealant early will help you avoid having to do extra work, pay for repairs, and risk failure.

Final Thoughts

Choosing the correct silicone sealant for connections between concrete, metal and glass is very important for any building envelope project in Vancouver. You can help make sure your joints last a long time by paying attention to things like how well they move, how well they stick to the substrate, what kind of cure you use, how you install them, and how the weather affects them. You can also get reliable products, local supplies, and technical assistance by working with BCBP.

If you choose the right sealant and install it correctly, your sealant joints will help make your building last and keep the weather out.