Manufactured home exterior doors are made like a sandwich with a metal or vinyl sheet on the outside, a Styrofoam core and a metal or vinyl sheet on the inside. They are sized by what the industry calls hole size. By that they mean that if you take the door out, what are the dimensions of the hole. You need to know this number and whether you want the hinges on the left or the right before you go to buy your new door. You will also have to make some choices about what kind of window, if any, you want. Pick up a roll of putty tape and some extra screws at the same time you buy the door.

Replacing a door is generally not difficult, but check for obstructions before you begin. Sometimes decks are built high enough they cover the screws on the bottom of the door. If that is the case you may have some major work involved in getting access to them. The putty tape will stick and compress better if it is reasonably warm. A reversible drill with hex head bits is very helpful (almost essential). Buy the replacement door, putty tape and some new screws. Remove all the old screws, carefully pry the door from the opening and clean off the old putty and/or caulking. I say carefully because if you try to muscle it loose it is VERY easy to tear siding loose along with the door.

Putty tape the new door, peel off the paper backing and shove the door into position. DO NOT loosen the screws that hold the new door in it's frame. These are what provide the strength to keep the door frame squared. The directions that may have come with the door will probably tell you to put three screws in at waist level on each side of the door and then work your way up and down. Before you get to many screws driven, check to make sure you have the new door in straight. Be careful not to drive the screws to deep. The power drills are strong enough that you can easily dent the aluminum door frame.

The door may or may not have come pre-drilled for a deadbolt lock. If not, you can buy drill bits that cut the right size holes, but I question the value of heavy locks on Manufactured homes. A heavy deadbolt lock may give you a feeling of security, but the reality is that if I want to break in, a pry bar or even a hard kick is going to break through the door itself, no matter how strong the deadbolt. You need enough lock to keep out kids and casual entry attempts and show visible damage for filing a police report. More serious locks just make more expensive repairs and will not deter a determined intruder.