Composite doors are very easy to instal. Typically, it takes about three to four hours to fitting a composite door, but depending on the nature of the job, the door installation process can be extended to a single day. In addition, the fitting process requires professional assistance. It is not recommended that you try this job yourself. You'd need two engineers to help you instal a composite door. You can make an appointment with the engineers by contacting the Composite Door Agency. Measures to ensure the fitting of a composite door are carried out before and after installation. Pre-installation checks shall include the removal of the existing door and the comparison of cavity measurements with the new composite door.