A flooded basement is not a situation you want to get home to and you ought to take care of that before you get a real problem on your hands. Using some clothes or boards to secure the basement door is not going to be of much help which is why you should get a contractor to do the job. With the right basement proofing techniques, the space will be free from moisture leakage which can cause a mold situation leaving your household exposed to fungal infections. To find the right contractor, make sure he or she has references you can check to see that he or she is able to do a great job. As far as your house and your finances are concerned, you should not be spending money on any professional unless you are sure the job output you will get from them is something you can live with. Get information on why the contractor thinks he is the best person for the job. If the response does not convince you that the person will do an outstanding job, look for someone else.
You should expect great things from a person who is experienced in basement waterproofing compared to someone who has just handled a few projects. It is not disrespectful to ask about this because you will be able to know how much responsibility you should give the contractor. Do not just think in terms of years when you are inquiring about the experience level. You should inquire about the projects the contractor has taken on and how the basements have held on ever since. You might find a contractor who got licensed ages ago but managed to get just a few contracts.
A license is necessary before you give the contractor the job. It is illegal to offer the services without a valid license and someone who is willing to break the law cannot be trusted. Ensure the services come with a guarantee of warranty because you will not have to pay more for the same if things do not work out after a couple of months. The basement contractor should discuss the techniques he or she used in the project with you before moving ahead with the plans.