Hello Paul,
What do you mean by 'just out of warranty'?
You have statutory rights that are automatically awarded to you under the Sale of Goods Act (SoGA). Technically there is a limit to when a warranty claim may be brought, though in practice it cant be longer than the life expectancy of a product and for practical reasons 6 years is about the maximum that the courts will allow. It is also subject to reasonable usage, and wear and tear.
Your warranty rests with the parties that signed the contract of sale, which for caravans is usually the dealer not the manufacturer. In some cases it may even be a finance house if you used one.
The problem is proving that the damage you have is the result of a fault that was either present at the time of sale, or there is a design or manufacturing fault rendering the product not fit for service.
If you wish to consider pursuing a remedy through SoGA I strongly recommend that you seek professional legal advice.