Filling the crack and repainting over it is the fastest way to make it disappear, and the fastest way to guarantee it comes back if the movement causing it hasn't actually stopped. This is one of the clearest cases where a cosmetic fix and a structural repair are entirely different things, and doing the wrong one first can make the eventual proper repair more expensive.
A repair that actually holds only starts once the cause is established and, where necessary, the movement has been confirmed to have settled.
The correct sequence
The monitoring step is often the one people want to skip, but repairing over movement that's still active means redoing the work once it's clear the crack has returned or widened. Where there's genuine doubt about whether movement is ongoing, that period of monitoring is not wasted time — it's what tells you whether you're fixing a static historic issue or a live one.
- Establish whether an adequate lintel exists above the opening at all
- Where movement may still be live, monitor with crack gauges or dated pencil marks over an appropriate period before any repair work begins
- If the wall needs support altered or a lintel replaced, needle and prop the structure above the opening properly before removing anything
- Install or replace the lintel to a specification adequate for the load and span
- Once movement is confirmed stable, repoint or rebuild the affected section in a mortar matched to the surrounding brickwork
- Redecorate only once the structural work is complete and settled
Why a cosmetic patch fails, specifically
Filler and paint have no structural role at all — they simply hide the gap. If the lintel is genuinely deflecting, or foundation movement is ongoing, the same forces that created the crack are still present, and they'll open the filler back up, usually along the same line, sometimes within a single change of season.
Painting over a crack also removes your ability to monitor it — you lose the visual reference point that tells you whether things are getting worse, which is one of the most useful pieces of information you have while deciding whether more invasive work is needed.
Working with a structural engineer
Where the crack pattern, width or location suggests anything beyond a simple lintel replacement, involve a structural engineer before pricing repair work. They'll specify the size and type of lintel needed, confirm whether foundation investigation is required, and set out any monitoring period needed before work proceeds. Needling and propping openings safely is specialist work and should not be attempted without proper temporary support design.
Confirming the repair has held
After the structural work and repointing, the wall should show no fresh cracking through a full change of season, ideally including whichever conditions — hot dry summer or cold wet winter — tend to bring out movement in that particular property. A dated reference mark left discreetly near the repair is a sensible way to keep an eye on it without needing to remember exactly where the original crack was.
Common questions
How long should movement be monitored before repairing?+
It depends on what's driving the movement, but a period covering a full season, or ideally the seasonal extreme most likely to trigger it, gives a much more reliable picture than a few weeks. A structural engineer can advise on the appropriate period for your specific case.
Can the opening stay in use while a new lintel is fitted?+
The opening usually needs to be needled and propped before the existing lintel is disturbed, which affects use of that doorway or window temporarily during the work. We plan this to minimise disruption where possible.
Will the repaired area match the surrounding brickwork?+
We match mortar colour, joint profile and, where bricks need replacing, brick type as closely as possible to the original, though very old or reclaimed brickwork can be harder to match exactly.
Get the crack assessed and quoted properly
We bring in structural engineering input where it's genuinely needed and give you a written, sequenced quote once the cause is confirmed.