The Smallest Line Item Protecting Your Biggest Asset

When strata councils plan exterior maintenance, paint gets most of the attention. It's what owners see, and it's what makes a building look cared for. But the thin bead of caulking around your windows, doors and wall penetrations is doing something paint can't. It's keeping water out of your walls.

On the West Coast, that job never stops. Metro Vancouver and the Fraser Valley see months of steady rain, wind-driven storms and constant freeze-thaw swings through the winter. A sealant joint that has cracked or pulled away gives that water a direct path behind the cladding. Once it's in, it can soak sheathing, rot framing and grow mould long before anyone sees a stain inside a suite.

The repair at the joint is cheap. The repair behind it often isn't. Many BC stratas have learned that lesson the hard way through building envelope remediation projects that cost owners far more than routine sealant maintenance ever would have.

Where Sealant Lives on a Strata Building

A typical low-rise or mid-rise strata has hundreds, sometimes thousands, of linear metres of sealant. The most important places to check are:

Window and door perimeters, where the frame meets the cladding
Wall penetrations, such as dryer vents, exhaust hoods, light fixtures, hose bibs and electrical boxes
Control and expansion joints in stucco, concrete and panel cladding
Transitions between materials, such as siding to stucco or cladding to concrete
Flashings and trim, including the ends of window head flashings and corner boards
Balcony and deck edges, where membranes, railings and posts meet the building
Roof-to-wall junctions and parapet caps

Each of these is a spot where two materials move differently with temperature and moisture. Sealant is the flexible link between them, and it wears out.

6 Warning Signs Your Sealant Has Failed

You don't need a ladder to spot most sealant problems. Walk the building on a dry day and look for:

Cracking or crazing. Fine surface cracks mean the sealant has lost its flexibility and is close to splitting.
Adhesive failure. The bead has pulled away from one side of the joint, leaving a visible gap. This is the most common failure and the most serious.
Cohesive failure. The bead has torn down the middle. Often a sign the joint was too thin or the wrong product was used.
Hardening or shrinkage. Press it with a fingernail. Healthy sealant gives; failed sealant feels hard and brittle.
Missing sections. Gaps where sealant has fallen out entirely, often at corners and around penetrations.
Staining, streaking or efflorescence below windows and joints. These are clues that water is already getting in.

Inside the building, watch for owner reports of drafts, damp window sills, bubbling paint or musty smells near exterior walls. Those reports are worth logging at every council meeting.

How Long Does Sealant Last?

There's no single answer. Lifespan depends on the product, how well the joint was designed and prepped, and how much sun and weather that side of the building takes. As a general guide:

Sealant type	Typical service life	Common uses
Silicone (high-performance)	15–20 years	Window perimeters, glazing, metal and glass
Polyurethane	8–12 years	Control joints, concrete, paintable areas
Hybrid / silyl-modified polymer	10–15 years	General exterior joints, paintable transitions
Acrylic latex	3–5 years	Interior and minor trim only, not for exterior envelope joints

South- and west-facing elevations usually fail first because they take the most UV and heat. For planning purposes, most stratas should expect a full exterior reseal roughly every 8 to 15 years, with spot repairs in between. Your depreciation report should list sealant as its own component so the cost is planned, not a surprise.

Why You Should Reseal During Your Next Exterior Repaint

The biggest cost in any exterior project is often access: scaffolding, swing stages, lifts or rope access. Once the crew is already on the wall for painting, adding sealant replacement costs far less than mobilizing a separate project later.

There are other good reasons to do both at once:

Better results. Joints are cut out and resealed before the final coats, so paint and sealant work together instead of fighting each other.
One disruption for residents. One set of notices, one window-access schedule, one cleanup.
A full inspection. Painters working every elevation up close often spot damaged flashings, rot or cladding issues early, while they're still small repairs.
Cleaner warranty coverage. One contractor responsible for the whole exterior finish.

If your building is already approaching a repaint, ask that sealant replacement be priced as part of the scope, not as an afterthought.

What a Professional Reseal Involves

Good sealant work is mostly prep. Running a new bead over old, failed caulking might look fine for a season, but it won't bond and it won't last. A proper reseal includes:

Inspection and mapping. Identify every joint type and its condition, elevation by elevation.
Full removal. Cut out the old sealant completely and clean the joint faces back to sound material.
Surface prep. Joints must be clean, dry and primed where the manufacturer calls for it. Rain is the enemy here, so timing and weather monitoring matter.
Backer rod. Foam rod is installed to set the correct depth and prevent three-sided adhesion, which lets the joint stretch without tearing.
Right product, right joint. Sealant is matched to the materials, movement and whether it will be painted.
Tooling. Each bead is tooled to press it into full contact with both sides and shape it to shed water.
Quality checks and documentation. Spot adhesion tests and photos give your council a record for the depreciation report and future planning.

A Quick Checklist for Councils and Property Managers

Walk the exterior once a year, ideally in late summer before the rains return.
Photograph and log any cracked, gapped or missing sealant.
Track owner reports of drafts, leaks or damp sills by unit and elevation.
Confirm sealant is listed as a component in your depreciation report.
Bundle sealant replacement into your next exterior repaint scope.
Ask contractors how they remove old sealant, which products they use and whether they install backer rod.

Protect the Envelope Before the Next Storm Season

Caulking is one of the least expensive parts of exterior maintenance, and one of the most important. Catching failed joints early keeps water where it belongs: outside.

Unitus Painting has helped strata buildings across Metro Vancouver and Western Canada protect their exteriors for more than 25 years. Our crews handle painting, caulking and joint sealants, power washing and rope access, so your building gets one coordinated plan instead of several separate projects.

Book a free exterior sealant and paint assessment for your strata today. Call us or request a quote at unituspainting.com.

Strata Caulking & Joint Sealant Guide for BC Councils and Property Managers

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