If you've determined your deck is unsafe, you'll need to either repair or retrofit it, or in some cases, rebuild it altogether. If rebuilding your deck is not feasible, there are improvements you can do on your own to strengthen your deck. However, some cases may require the professional services of an engineer and contractor. Knowing what products and tools are needed from the beginning will set you on the right course to safety. Remember, when hiring a professional, be sure they are licensed and have a good reputation. Once the work is done, don't forget about your deck – it needs to be checked and inspected on a regular basis.