Hardboard and softwood panels are available as well, however most flush doors have hardwood veneer face panels. Some doors are made with cutouts for windows or louvers. Flush doors are used both as interior and exterior doors, but if used as exterior doors they should be made with waterproof adhesives rather than water-resistant adhesives.
Very often, you can tell whether the proper adhesive was used just by looking at the top edge. Most quality doors will have a small red plastic plug in the edge, indicating that the door was bonded with a waterproof adhesive suitable for exterior use. If an improper adhesive has been used, the exterior face panel eventually begins to delaminate and peel.
A solid-core flush door is fire-resistant, provides greater heat and sound insulation and dimensional stability than a hollow-core door. The solid core of a flush door can consist of wood blocks or a composition material that has been formed into a rigid slab, while a hollow door is generally made of wood or wood derivatives such as cardboard that have been formed into a honeycomb or parallel strips.
In some cases, the hollow-core flush door is used as an exterior door, but this is not considered quality construction because it is not resistant to heat, sound or fire. When used on the exterior, the door should be treated with a water-repellent adhesive and bonded with waterproof adhesive, but this is sometimes omitted.
The metal-clad insulated entrance door is a variation of the flush door, and is available in a range of surface styles. The door basically consists of metal face panels with an insulating core. These doors may also be provided with a thermal break to separate the interior parts of the frame and door panel from the exterior parts, thus minimizing condensation during the winter months.
If the exterior door has glass panes close to the door lock, it is not considered secure. If the door lock can be reached by breaking a glass pane in the door or side panels, an auxiliary lock should be installed. In addition, after you take possession of the house it is recommended that you replace all door locks, or at least have them rekeyed.
The exterior doors inspection should be conducted during the exterior and interior inspection. Check the condition of the door during the exterior inspection, then check its operation during the interior inspection. A wood door should be checked for cracked, chipped and delaminating sections. Inside, check the doors for ease of operation. A steel door should be checked for dents and scratches, which will rust if not painted.
A fiberglass door should also be checked for cracks, because it can be affected by severe impact. Check to see whether the door opens and closes easily, and check for weatherstripping around the exterior joints to make sure air infiltration is reduced to a minimum. If you notice any problems during the exterior doors inspection, record them on your worksheet for future correction.