A blind header is a short header (a brick showing its end face) in a bond pattern that does not extend the full depth of the wall. The brick appears to be a header in the bond, but does not pass through to the rear face of the wall. Blind headers are used to make the bond pattern work without every header running as a through-stone across the wall.
Why blind headers?
| Reason | Explanation |
|---|---|
| Completing the bond | Allowing the pattern of stretchers and headers to work correctly |
| Cavity wall construction | In a cavity wall, headers need not extend through to the inner leaf |
| Insulation | Through-headers form cold bridges in insulated walls |
| Appearance | The facade displays the desired bond pattern |
Application in bond patterns
In traditional solid walls, headers run across the wall to tie the inner and outer leaves together. In modern cavity walls, this is undesirable:
- The inner and outer leaves are separated by a cavity (with insulation)
- Through-headers would form cold bridges and moisture bridges
- Therefore, blind headers are used in the outer leaf
- The connection between the leaves is made with wall ties
Blind header vs. snap header
- Blind header: a three-quarter or half brick that looks like a header
- Snap header: a brick cut to size and used as a header
- Both serve the same purpose: making the bond pattern work
Tips for the DIYer
- Use blind headers when building a half-brick outer leaf in an upright bond
- Cut the bricks neatly to size for a crisp result
- Always use wall ties for the connection between inner and outer leaves
- Ensure the blind header has sufficient bearing (at least 50 mm)
Related terms
- Header: the short face of a brick
- Stretcher: the long face of a brick
- Cavity wall: wall with two leaves and an intermediate space
- Bond pattern: the pattern in which bricks are laid