Updated August 2024
At our company, we use both traditional double glazing and LandVac vacuum glass, depending on the specific needs of each project. Double glazing units are a simple yet effective innovation – two panes of glass with an air gap between them provide far better insulation than a single pane. This design can reduce thermal conductivity by up to 83% and can be so efficient that it helps to heat the room. However, maintaining their efficiency and ensuring long-term benefits requires proper care, particularly for the perimeter seal, which is crucial for the unit’s performance.
Standard double glazing typically lasts between 10 and 25 years. However, that’s only a rough average. Some units fail in less than 12 years, especially those facing strong sunlight or exposed to temperature swings. Others, when manufactured and glazed correctly, can last 30 years or more.
The first factor is the materials themselves. Most manufacturers use similar basic components, but the quality of those components and the skill of assembly vary widely. Windows facing south or in harsher environments may experience greater thermal stress, causing adhesive failure over time.
At Gowercroft, we use an internally wet-glazed system. This allows for better bonding and fewer weak points in the seal. That’s how we regularly achieve lifespans of around 30 years, well above the industry average.
How the glass is held in the frame is just as important as what the glass is made of. Our wet-glazing method involves sealing the glass internally and capping it with mastic externally. This keeps moisture away from the vulnerable edges of the unit.
Dry glazing, which relies on pressure and gaskets, is faster but not as watertight. Over time, that can lead to water ingress and a much shorter lifespan.
Every double-glazed unit has a perimeter seal. It’s usually made of butyl mastic and holds a perforated metal spacer bar filled with desiccant. The desiccant absorbs moisture from the air gap to keep the panes clear.
But if the seal fails, as it often does with poor glazing or weather exposure, moisture enters the unit. The desiccant can’t cope, and you start seeing misting or condensation.
To combat this, we:
Use internally beaded glazing with waterproof mastic caps
Design drainage channels into the glazing rebate
Use high-spec materials with performance warranties
At Gowercroft, our sealed units come with a 10-year no-quibble guarantee. This covers both the cost of the unit and the labour to replace it. That’s not common in the industry. We offer it because we’re confident in our manufacturing process and because we believe in long-term value for our customers.
If you’re looking for even better performance and durability, vacuum glazing is a smart option. Our LandVac vacuum glass comes with a 15-year warranty, but it has been tested to perform reliably for at least 25 years with no reduction in efficiency.
These results come from rigorous ageing and exposure tests that simulate decades of real-world use. In truth, the lifespan could exceed 50 years, making it an excellent investment for long-term performance.
There’s no one-size-fits-all answer. The longevity of your double glazing depends on the quality of materials, the glazing method, and how well the units are protected from moisture.
That’s why we focus on every detail, from our internally wet-glazed system and carefully designed drainage to the high-spec components we use as standard. Whether you choose traditional double glazing or our industry-leading LandVac vacuum glass, you’ll benefit from our commitment to performance, durability, and honest guarantees.
Contact us today to find out which glazing solution is right for your home or project.