Desired Service Life and Guarantees: The Difference

When choosing timber fencing, one of the most important but often misunderstood aspects is the longevity of the product. In recent years, a growing number of suppliers and manufacturers have started marketing their fencing products with a ‘desired service life’ of 15, 25, or even 60 years. While this might sound reassuring at first glance, the term ‘desired service life’ can be misleading if misunderstood or taken at face value. It’s essential for consumers to distinguish between a ‘desired service life’ and an actual guarantee, especially when investing in a product as critical as fencing, where longevity, performance, and security are all paramount.

What Is a Desired Service Life?

A desired service life is a theoretical estimate of how long a product might last under ideal conditions, based on standards like BS 8417, the British Code of Practice for the preservative treatment of wood. The standard itself sets out guidelines for how timber should be treated according to the wood species, intended use, and environmental exposure. For example, it states that timber designated for ground contact should be treated to a higher level (Class 4) than timber used above ground (Class 3), with potential lifespans of 15, 30, or 60 years specified.

However, a desired service life is not a promise. It’s a goal - an aspiration that assumes all steps in timber treatment and handling are carried out perfectly. It does not guarantee the product will actually last that long in the real world, particularly if the timber hasn’t been treated properly, shortcuts have been taken in its preparation, or it is incorrectly installed.

Why It Can Be Misleading

There is growing concern that some manufacturers may use ‘desired service life’ claims as a marketing tool without providing the product integrity or evidence to back it up. Without a formal, enforceable guarantee, the onus is entirely on the buyer to trust that the treatment process and material quality have met the necessary standards. Unfortunately, unless you have industry expertise or specific lab equipment, verifying this can be virtually impossible.

Timber is a naturally beautiful and versatile material, but it is also vulnerable to rot, decay, and insect attack if not treated correctly. A piece of timber that is supposed to last 30 years based on a ‘desired service life’ could fail in as little as three or four years if the treatment has been poorly applied or if inferior timber has been used.

The Importance of Proper Timber Treatment

At Jacksons Fencing, we’ve been supplying our timber fencing since 1947 and a 25 year guarantee for many more years than the guarantee provides. This isn’t based on a theoretical lifespan. It’s a promise backed by a proven, carefully controlled in-house treatment process known as Jakcure^®.

The Jakcure^® treatment process is critical to delivering real, long-lasting performance. It starts with selecting the right timber, followed by drying it in a kiln to ensure the moisture content falls below a specific percentage. Timber that isn’t sufficiently dried won’t absorb preservative effectively. Proper kiln drying ensures that moisture levels are reduced throughout the timber, not just on the surface.

The dried timber is then placed in an autoclave where a vacuum removes air from the wood’s cellular structure. It is then flooded with preservative, and a 12-bar pressure is applied to drive the treatment deep into the heartwood over a period of around three hours. A final vacuum removes any surface chemical, which is pulled back into the wood. The timber is then stored for a minimum of 48 hours before despatch to allow for complete absorption and effectiveness of the preservative.

This level of detail and commitment to treatment is not optional if you want timber to perform to the standards often claimed by ‘desired service life’ marketing. Simply quoting the BS 8417 standard doesn’t guarantee that the timber has been treated appropriately for its class or end use. A Class 4 designation, for example, might come with a desired life of 15, 30, or even 60 years, but the treatment must reflect that goal in reality, not just in theory.

Why a Real Guarantee Matters

Unlike a desired service life, a guarantee is a legally binding promise. Our 25 year Jakcure^® guarantee means that the timber will not fail from rot or insect attack within that period, but if it does, we will replace it. That’s a level of accountability that desired service life claims simply don’t offer.

But offering such a guarantee isn’t just about confidence in the product, it’s about investment in the process. The thorough Jakcure^® treatment takes more time and incurs higher costs, but this pays off in the long term. Poorly treated timber, ironically, can have a shorter lifespan than untreated wood; lasting as little as three to four years in contact with the ground, compared to five to six years for untreated timber.

When viewed over the long term, our customers find that the initial cost of a high quality, guaranteed product works out to be far more economical. With poorly treated timber, you may have to replace your fencing five times over a 25-year span. So while the upfront cost of premium timber may be higher, the lifetime cost is significantly lower.

The difference between a desired service life and a genuine, enforceable guarantee is more than semantics, it’s about trust, quality, and long-term value. Consumers deserve clarity and honesty when making investment decisions about their properties, especially when it comes to security and infrastructure.

At Jacksons Fencing, we believe in transparency, responsibility, and standing behind what we sell. That’s why we continue to raise awareness around proper timber treatment, and why we back our products with a 25 year guarantee - not just a hope or a wish, but a promise you can rely on.

So next time you see a claim of a 30 year or even a 60 year ‘desired service life’, ask: Where’s the guarantee? If there isn’t one, the value might not be as real as it seems.