Weatherproofing & silicone
Remediation scoping, access planning and joint programs.
Weatherproofing & silicone →← Technical guides
Weatherproofing
Sealant lifespan and maintenance schedules
Correctly specified and installed silicone facade sealant typically lasts 15 to 20 years; urethane commonly 7 to 12. Service life is shortened by UV exposure, joint geometry that is too shallow or too narrow, missing primer and sealant applied over old sealant. Inspect every two to three years and plan remediation by elevation, since south and west exposures fail years before north.
How long does facade sealant last, and when should it be replaced? For building engineers and owners planning capital work.
01
Realistic service life
Manufacturer warranties describe the material under correct conditions. Actual service life is a function of exposure, movement and installation quality. Two identical buildings on the same street can be a decade apart in sealant condition based on orientation alone.
| Sealant type | Typical service life | Where it belongs |
|---|---|---|
| Structural silicone | 20+ years | Glass-to-frame structural attachment; factory-applied wherever possible |
| Weatherseal silicone | 15–20 years | Perimeter and movement joints on exposed elevations |
| Polyurethane | 7–12 years | Horizontal and traffic-adjacent joints, paintable conditions |
| Acrylic / latex | 3–7 years | Interior and protected conditions only; not an exterior facade material |
02
What actually shortens it
- UV exposure
- South and west elevations degrade first. Chalking and surface crazing appear years before the north face shows anything.
- Wrong joint geometry
- A joint should be roughly twice as wide as it is deep at movement joints, with backer rod producing an hourglass bead. A deep, square bead tears itself apart in thermal cycling.
- No primer
- Substrate-specific primer is what produces adhesion on masonry, precast and coated metal. Skipping it produces clean adhesive release in three to five years.
- Sealant over sealant
- Re-caulking over an existing bead is the single most common cause of a repeat failure. Full removal to clean substrate is not optional.
- Movement beyond capacity
- Every sealant has a rated movement capability. A joint that moves more than the sealant can extend and compress will split cohesively no matter how well it was installed.
03
A workable maintenance schedule
Facade sealant is a capital item on a predictable cycle, not an emergency repair category. Treating it as scheduled work is meaningfully cheaper because access — swing stage, rigging, permits — dominates the cost and can be mobilized once instead of three times.
- Annual, from grade
- Visual walk of the base and accessible elevations. Look for chalking, splits, staining below joints and displaced backer rod.
- Every 2–3 years, close-up
- Sampled close inspection at the worst exposures, with hand-pull adhesion checks at representative joints.
- Year 10–12
- Condition survey by elevation and a budget line for the first remediation, usually the south and west faces.
- Year 15–20
- Full replacement program on remaining elevations, executed in as few rigging mobilizations as possible.
04
Spot repair vs. elevation remediation
Spot repair is appropriate for isolated mechanical damage — an impact, a penetration, a single displaced joint. It is the wrong response to age-related failure, because the adjacent joints are the same age, the same exposure and the same installation, and they will fail on the same timeline.
Once a sampled inspection finds adhesive or cohesive failure at multiple locations on one exposure, the economic move is to remediate that elevation completely while the access is already rigged.
Related questions
Can new sealant be applied over the old bead?
No. The new material bonds to the old sealant, not to the substrate, and the assembly fails at the original interface. Every remediation scope should specify full removal to clean substrate.
How do I know whether the leak is the sealant or the glazing unit?
Water travels, so the interior stain rarely marks the entry point. Sequential water testing from the bottom up isolates the failing component — perimeter joint, gasket, weep path or the insulating unit itself.
Is silicone always the right choice?
For exposed vertical facade joints, usually yes. Urethane still makes sense in traffic-adjacent horizontal joints and where the joint must be painted, at the cost of a shorter replacement interval.
Where this applies
Services this guide relates to.
Curtain wall
Structural and weatherseal silicone within curtain wall assemblies.
Curtain wall →Storefront systems
Perimeter sealing at storefront framing and masonry transitions.
Storefront systems →More guides
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