Two types of leaks often plague patio doors. Water leaks mean that damage can occur to your floor, wall and carpet. Air leaks end up costing you more money each month in your energy bills. Both varieties of leaks should be taken care of right away. Fortunately, the repairs aren't difficult.
Pull cracked, broken or brittle weatherstripping out of the preformed slot it sits in. You may have to cut it out with a utility knife. If your weatherstripping is attached with screws, remove it with a screwdriver. Replace with new weatherstripping.
Pry off a piece of the door trim, using a crowbar. Look for air leaks. The door should have rope insulation or spray foam insulation filling in the gaps between the door frame and stud walls. Sometimes, this may have not been done or could be worn out. If you need to replace or install some door insulation, remove the trim.
Press new rope installation in place and work your way around the door. Spray non-expanding door foam into the remaining gaps. Let dry for several hours. Reinstall all of the door trim, using drywall screws and a cordless drill.
Inspect the sill area of the patio door. This is the most common place for water infiltration.
Insert a hole punch into the hinges and remove the pins to remove the doors from the door frame. Use a hammer to punch out the hinge pins. Move the doors to the side.
Remove the sill plate with the cordless drill and screw bits. Keep the old sill to use as a template for the correct length when you cut down the new sill.
Remove the rubber seal from the new sill. Cut it to length with the utility knife.
Cut the new sill to length, using a hacksaw. Reinsert the rubber seal into the sill.
Install the sill with drywall screws or screws specially made for concrete, depending on what material the floor is made of under your sill. Tighten down with the cordless drill.