As a tradesman the chances are that you'll be in contact with the public on a daily basis. Tradesman's liability insurance is designed to cover claims made against you as a result of damage or injury to a third party, and most policies also include Product Liability Insurance as standard.
If you have anyone working for you (even temporarily) the law states you must have employers' liability insurance (subject to a few criteria and exclusions). Where this cover is selected policies provide up to £10,000,000 of cover.
Tradesman's Liability insurance can be extended to include Tools, Materials and Equipment against theft or malicious damage. Tools, materials and equipment insurance can also be arranged as a stand-alone policy.