Trailer Tyre Safety: What Every Service Engineer Must Know

When trailers are involved, tyres are one of the most critical safety components – yet they are still too often overlooked. At Towing Solutions, trailer tyre safety is not an afterthought; it is a core part of our Trailer Servicing & Maintenance Courses and a major factor in preventing incidents on UK roads.

Whether you already work in the industry, maintain your own trailer fleet, or are developing your skills as a professional trailer service engineer, understanding and applying robust tyre checks is essential. This guide brings together best practice, UK legal references, TyreSafe advice and practical training insight from Towing Solutions.

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Why Trailer Tyre Safety Matters

UK road safety data and industry campaigns continue to highlight the dangers of defective tyres. TyreSafe reports that, on average, more than 150 people are killed or seriously injured each year in incidents where defective tyres are a contributing factor.^{TyreSafe – Case for Action}

When a trailer is attached, the risks multiply. Extra load, uneven distribution, incorrect tyre pressures and higher operational stress can quickly turn a small defect into a serious emergency. A tyre issue on the towing vehicle is dangerous; a tyre failure on the trailer – especially at speed or when fully loaded – can be catastrophic.

The UK Government’s own guidance on towing a trailer with a car highlights wheels and tyres as a specific safety check, including tread depth, condition and correct inflation for the load being carried.^{GOV.UK – Tow a trailer with a car: safety checks}

UK Legal Requirements for Trailer Tyres

For light trailers towed by cars and light vans, tyres must meet the same basic legal standards as those fitted to cars. This includes:

• Minimum tread depth: at least 1.6 mm across the central three-quarters of the tread and around the entire circumference of the tyre.^{TyreSafe – Tread Depth Guide}
• Tyre condition: free from dangerous cuts, bulges or exposed cords, and suitable for the purpose and load.^{GOV.UK – Trailer safety checks}
• Correct inflation: tyres must be inflated to the manufacturer’s recommended pressure for the load being carried.

For heavier trailers towed by vehicles over 3,500 kg gross vehicle weight, different tread depth rules apply (typically 1 mm minimum), and operators should refer to specific DVSA and government guidance.^{GOV.UK – Tyre defects and damage: HGVs, buses and trailers}

DVSA and TyreSafe both strongly recommend replacing old trailer and caravan tyres even if tread depth appears adequate, particularly when tyres are over 7–10 years old, due to age-related deterioration.^{DVSA – Caravan, motorhome & trailer tyre reminder}

What Should Be Checked During a Trailer Tyre Inspection?

A professional trailer servicing inspection should include a thorough tyre and wheel check as standard. Key elements include:

• Tread depth – Check with a gauge across several points. While 1.6 mm is the minimum legal limit for light trailers, many safety organisations recommend replacing at 3 mm to maintain wet grip and braking performance.
• Tyre pressure – Pressure should match manufacturer recommendations, adjusted for the trailer’s payload. Under-inflated tyres run hotter, wear faster and are more likely to fail; over-inflation reduces contact patch and grip.
• Sidewalls and surface condition – Look for cuts, bulges, cracking, flat spots, or embedded objects. Any damage or deformation can indicate weakened structure and must be investigated.
• Tyre age – Check date codes and be especially cautious with tyres over 5–7 years old, even if tread appears healthy. Trailers that stand for long periods are prone to age-related cracking.
• Load rating and speed rating – Ensure the tyre’s load index and speed symbol are appropriate for the trailer’s maximum authorised mass (MAM) and intended use.
• Wheel security – Check wheel nuts/bolts for correct torque, clean mating faces and any signs of fretting or movement. Wheel loss is a serious and avoidable risk.

For simple, shareable monthly checks, TyreSafe’s A.C.T. message – Air pressure, Condition, Tread – is a great resource for both engineers and end users.^{TyreSafe – The Checks}

TyreSafe & Towing: Essential Reading

If you want to deepen your knowledge around tyre care while towing caravans or trailers, TyreSafe provides an excellent overview specifically for towing safety:^{TyreSafe – Towing Safety Guide}

For trailer service engineers, this is invaluable background to complement hands-on skills and ensure your advice to customers aligns with national safety campaigns.

Ongoing Support: Our Trailer Servicing Help Group

Training with Towing Solutions doesn’t end when you leave the classroom. Every delegate who completes a trailer servicing course is invited into our long-running Trailer Servicing Help & Support WhatsApp Group.

Inside the group you’ll find:

• Experienced trailer service engineers and mechanics from across the UK
• Real-world troubleshooting and technical support on tyres, brakes, electrics and running gear
• Knowledge sharing linked to the key industry and certification bodies we work with
• A supportive network that understands the day-to-day reality of trailer servicing work

No matter which certification route or association you choose, you’ll be supported. You are never working in isolation – there is always someone to ask, a second opinion to seek and experience to draw on.

Trailer Safety Begins with You

Whether you work on leisure caravans, horse trailers, boat trailers, plant trailers or commercial fleets, tyre safety must be a top priority in every trailer service. Robust trailer tyre checks:

• Reduce the chances of breakdowns, blowouts and roadside incidents
• Improve safety for your clients, their customers and all other road users
• Protect your professional reputation and your customers’ vehicles and cargo
• Support compliance with UK roadworthiness expectations and best practice

At Towing Solutions, we are committed to raising standards across the UK trailer industry through high-quality training, recognised certification routes and genuine aftercare support. Tyre safety is just one part of that, but it is a crucial part.