Prehung Doors
‘Prehung’ refers to a door complete in a frame.
A prehung door consists of three main components:
- Door leaf – this is the actual panel that swings in the opening
- Door jamb – liner or frame that surrounds the opening on which the door leaf is hinged
- Stops – usually ‘planted’ onto jamb. This is the part of the door frame the door hits when it closes
Prehung Door Specifications
Unless otherwise specified a standard pre-hung door will be supplied with the following:
- Standard Jamb thickness of 25mm – either in MDF or Pine.
- Standard Jambs can come as either grooved (to receive linings) or architrave. Both made to fit 90mm framing and 10mm linings
- Floor clearance under the door is 20mm
Sizing Calculations
Formulae – to work out sizing based leaf sizes use the following calculation:
- Height = Door leaf height + 57mm
- Width = (single) Door leaf width + 75; (Pair) Door leaf width x 2 + 76
Trim size means the size of the opening required to fit the prehung door. This includes clearance to fit.
Hanging
To work out the hanging of the door i.e. the ways it swings, use the diagram below as reference. Always imagine the door as swinging towards you.
Jambs
Standard jambs come in two main profiles:
- grooved
- architrave
Both are made to fit for 90mm framing and 10mm linings both sides. The standard thickness of jambs is 25mm, either in MDF or Pine.
Door Construction
A door is made up of the following parts:
- Subframe
- Skins – generally MDF and different options for paint finish
- Core
Subframe
Doors are made with a FSC rated pine sub frame 15-25mm thick and with MDF skins.
Skins
Doors are made with MDF skins ranging in thicknesses from 3mm, 4mm and 6mm. The greater the skin thickness, the better the paint finishing.
Cores
Doors are available as Hollow Core, Poly Core and Solid Core.
Hollow Core
Hollow core doors are constructed with a thin veneer of high quality wood applied over a core of honeycombed cardboard.
Poly Core
A Poly Core door utilises the same sub frame construction however it has a higher density polystyrene core.
This gives it a more sturdy feel without the addition of too much weight.
Solid Core
Solid Core doors represent an interim construction method, in which a fine grade surface wood veneer is glued over a
solid core made of engineered wood, such as MDF or particle board. This gives the door a very solid feel and a greater level of sound proofing.
Cavity Sliders
- Standard jambs can come as either grooved (to receive linings) or architrave. Both made to fit 90mm framing and 10mm linings. However custom jamb sizes and set ups can also be made to order
- All cavity sliders are supplied as super sliders which means they have aluminium or steel stiffeners built into the core for extra stability
- Floor clearance under the door is 25mm, to allow for carpet, tiles or timber flooring
- Cavity sliders are available for standard door widths 610 – 910mm with custom sizes available on request
- Standard size cavity sliders come assembled and ready to install
Sizing Calculations
Formulae to work out sizing based leaf sizes use the following calculation:
- Height = door leaf height + 90mm
- Width = (single) door leaf width x 2 + 45mm; (Pair) door leaf width x 4 + 35mm
