A reveal is the side of a wall opening — the piece of wall you see when looking at a window or door opening from the side. Every opening in a wall (window, door, passage) has two reveals (left and right) and a soffit (the top). The reveal is where the frame sits against.
Reveal, jamb and rebate
| Term | What it is |
|---|---|
| Reveal | The full side of the wall opening |
| Jamb | The visible part of the reveal alongside the frame |
| Rebate | The step in the wall where the frame sits against |
In a cavity wall, the frame usually sits in the rebate: the inner leaf extends further inward than the outer leaf, creating a ‘lip’ for the frame to sit against.
Finishing a reveal
Interior
- Plastering — Most common, with a corner bead for a clean edge
- Plasterboard — Strips of plasterboard glued or screwed to the reveal
- Painting — After plastering or plasterboard installation
Exterior
- Exposed brickwork — The reveal is neatly pointed
- Render — For rendered facades, the render continues over the reveal
- Aluminium/PVC trim — Clean finish, especially with PVC frames
Insulating a reveal
When replacing frames or retrofitting insulation, the reveal is a weak point (thermal bridge):
- Thin insulation board (20-30 mm PIR) glued to the reveal
- Insulated sub-frames — PVC frames with integrated insulation
- Sealing tape — Breathable on the outside, airtight on the inside
Common mistakes
- Not insulating the reveal during cavity wall insulation — Condensation on the cold reveal surface
- Forgetting corner beads — Plaster crumbles at the reveal edges
- Forgetting sealant between frame and reveal — Draughts and moisture ingress
Related terms
- Window frame
- Threshold
- Cavity wall
- Facade
- Insulation value (R-value)