We agree that Weber products meet the product specifications and will be free from any defect. Any guarantee with regard to the performance of Weber products will be subject to its professional and practical application of Weber products in accordance with our instructions and specifications. However, we have no influence over specific site conditions and therefore, if in doubt, the user should first carry out sufficient tests to ensure that the product is suitable. In special cases, obtain advice. Should our product prove defective, we undertake to replace any defective material. This guarantee will fall away in the event of Weber products being contaminated by the addition of sand, cement or substance other than recommended by us.