Design & construction features , advantages & disadvantages

• Flush doors can be faced with hardboard , plywood or plastic laminate.
• This type of door has the advantages of a plain face that is easy to clean and decorate ; it also free of the mouldings that collect dust.
• The facings of flush doors are very vulnerable to damage at the edges : therefore a lipping of solid material should be fixed to at least the vertical edges ( good -quality doors have lippings on all four edges ).
• Small glazed observation panels can be incorporated in flush doors when the glass panel is secured by loose fixing beads.

The forms of flush door construction are many and varied , but basically they can be considered as:
cellular cone flush doors

• These doors are made with a cellular core in a light softwood frame with lock and hinge blocks , covered with plywood or hardboard facings glued to the frame and core both sides.
• These lighweight doors are for light duty such as internal dosmestic doors.
• They do not withstand rough usage and provide poor acoustic privacy , security and fire resistance.
• THey are mass-produced in a small range of standard sizes and are cheap.

Skeleton core flush doors

• These doors are made with a core of small section timbers
• THe main members of this structural core are the stiles and rails , with intermediate rails , as a base for the facing of plywood or hardboard.
• The framing core members are joined with glued , tongued and grooved joints
• A flush door with a skeleton core occupying from 30 percent to 40 percent of the core of the door is a light duty door suitable for internal domestic use.
• A similar skeleton core flush door with more substantial intermediate rails in the core , where the core occupies from 50 percent to 60 percent , is a medium duty door suitable for use internally in domestic and publi buildings and for external use in sheltered positions
• This more substantial door will withstand normal use and maintain its shape stability better than a cellular core door.
• However , the facing still has a tendency to deflect betweeent he core members.

Solid core flush doors

• These doors are made with a core of timber strips glued together , with plywood facings both sides glued to the solid core.
• These doors are edges with vertical lipping to provide a neat finish
• These doors may be used as fire doors
• Because of the solid core , these doors have better shape and surface stability and acoustic resistance than the cellular or skeleton core flush door
• Their facings generally ramain flat throughtout their life.
• These doors are more expensive than cellular core or skeleton core doors.