How to Determine Reveal Size

Introduction to Reveals

The Reveal is a timber surround fitted to the fin of the window or door and used for installing the product into timber framing.  The reveal becomes the frame of your window or door covering the stud. The architrave attaches to the reveal to cover the gap between the reveal and the plasterboard (or internal lining).  A variety of reveal sizes are available depending on your construction.

The size of the reveal is the combined width of the timber stud, the internal lining and cavity (for brick veneer).

Reveals for External Cladded Applications

This is relevant for timber cladding, blue board cladding or any other type of cladding up to 25mm thick.

Reveal Size  =  Internal lining (say 10mm)  +  Stud Size (say 75mm) =  85mm (use closest standard size 86mm)

How to determine Reveal Size for External Cladded Applications
Diagram 1: Window with reveal for External Cladded Applications

If bracing ply is used, you will need to add the thickness of this to the reveal size.

Reveals for Brick Veneer

Reveal Size  =  Internal lining (say 10mm)  +  Cavity (say 35mm)  +  Stud Size (say 75mm)  =  120mm (use closest standard size 116mm)

Reveal Diagram for Brick Veneer
Diagram 2: Window with reveal for Brick Veneer Application


Standard size reveals

Refer to the chart below for reveal sizes for external claded applications and brick veneer.

External Cladding
Stud Size (mm) Reveal Size* (mm)
70 81
75 86
90 98
100 110
Brick Veneer
Stud Size (mm) Reveal Size^ (mm)
70 116
75 116
90 138
100 138

Note: 138mm is the largest standard reveal size available. 105mm is also a standard size.
* Based on 10mm internal lining.
^ Based on standard brick veneer construction with 10mm internal lining.


What is the alternative to using Timber Reveals?

You may not need reveals on your windows and doors.  If you have a finished opening (often when removing an old window the finished opening will still be in place), you can slot the window into the opening and screw it into place through the jambs.  You can then simply silicon around the outside of the product or use some angle to cover any gaps.

Windows and doors come with an aluminium fin attached.  For this type of installation, the fin can be removed either by us or by yourselves on site.

Things to remember

Reveals add 40mm to the height and width of a window.
Reveals add 20mm to the height of a door and 40mm to the width of a door. Doors do not have a sill reveal.

When ordering a product, you are ordering the size to the outside of the aluminium.  Make sure you specify if it is the product size, the overall size or the stud opening size that you have measured.