How to Install a Door

Remodeling magazine's 2010-2011 Costs vs. Value Report showed that the number one home improvement project that provided a return on investment is a new front door. At a total cost of $1,218, a mid-range, prehung steel exterior door returned 102 percent at sale. If you're able to shave off more of that cost with a do-it-yourself door installation, that's a better return, right? Before you decide if door installation is a DIY project you want to take on, consider these seven tips on how to install a door before committing to the project.

How to install a door

1. Installing a door and installing a prehung door are two different things. Installing a prehung door means you're installing a door and the door frame to which it's been hung.
2. Once you've purchased the correct size of prehung door, you need to first read the manufacturer's directions. Don't forget that you may need to know your Homeowners' Association rules and local building codes.
3. You'll need to remove your existing exterior door by using a hammer and screwdriver to loosen the hinge pins. Using a prybar, remove any trim around the door's frame. Use an electric screwdriver to remove the hinges and both sills.
4. Using a reciprocating saw, carefully cut out the existing door frame.
5. Test door fit before leveling and weatherproofing subsill. Use shims to make the jambs and sills fit both tight and level, ensuring the door has clearance and isn't gapping in the frame.
6. Caulk and insulate door frame.
7. Finish door if necessary with paint and hardware, such as a deadbolt. Prehung exterior doors can be purchased prefinished or you can paint a primed prehung exterior door yourself.

Exterior steel doors can cost between $150 and $800. If your skill or physical strength is borderline, you might want to consider paying for professional door installation, rather than accidentally damaging an expensive purchase like a new exterior steel door. "Steel doors can dent easily, and you can't fix dents," said Taylor Joe Goldsmith, vice president of marketing and sales at Joe Goldsmith Construction.

Lowe's considers installing a prehung exterior door an advanced-level do-it-yourself project. If you're considering replacing interior doors, too, you may want to start with simply installing a new door, instead of installing a prehung exterior door. Interior doors typically cost less than exterior doors, and replacing an interior door is considered an intermediate-level DIY project.