After a long, Louisville summer of use, your sliding patio door may not be in the same shape it was when the summer first started. The door may not slide as well, the door lock could be broken or it squeaks when you try to open it. If you are facing any of these problems, winter is a great time to start looking for a replacement door so you are ready to have it installed as soon as spring gets here.Here are the 5 most common signs that your sliding patio door is in need of being replaced.The Patio Door Won’t SlideWhen the patio door stops sliding there could be multiple reasons for it. The rollers could be full of dirt and gunk from years of not being cleaned. It could also be there is a hidden structural problem or that there is a rotten sill underneath.Regardless of the reason, it is best to call in the professionals when the patio door won’t easily slide any longer. A professional will be able to fix simple problems or recommend a good replacement patio door.The Door Squeaks so Loud It Could Be Used as an AlarmIf you don’t have to worry about a lock on your sliding patio door because the squeaking is so loud it would wake up the neighborhood, it is time to take action. A squeak this loud normally isn’t one that can be repaired. For minor squeaks you can clean the track and spray dry-silicone spray lubricant on the wheels.For squeaks as loud as an alarm, the wheels are most likely beyond repair and the patio door needs to be replaced.The Patio Door and Base Are RottedIf you happen upon rot in your patio door and base when you are cleaning or making minor repairs, you have a larger project in front of you. Any rot, rust or disintegration of the patio door requires a replacement. This is not damage that can be repaired.If the base is rotted, you are going to want to call in a professional as there may be damage under the base, as well. This additional damage may require repairs to the structure of the house before the new sliding patio door and base can be put in.The Patio Door Lock has Been Broken for AwhileIf you have been living with a broken lock on your sliding patio door for a while now, you are just asking for trouble. Most home burglaries happen because the thief was able to find an unlocked door or window to enter the home through.Before you become another statistic, by letting a thief get into your home through an unlocked patio, have your door replaced.Not Worth Painting It Yet AgainIf you can’t stand another session of sanding, painting and filling in gaps on your sliding patio door again, it is time to replace it. There are only so many coats of paint you can put on a sliding patio door before it is beyond the help of paint, anyway.