Flaunching is the weathered top of the chimney
Cracked chimney flaunching can look straightforward, but the visible sign does not always sit directly over the fault. On this page the important question is cracks in the mortar bed around chimney pots at the top of the stack. For cracked chimney flaunching, the position of the problem, the weather when it appears and whether it is changing are more useful than guessing from one photograph.
Pay particular attention to visible splits around the base of a pot, pieces of mortar missing from the chimney top, and dampness that seems to come from within the stack rather than the roof junction. Those observations are worth passing on because they describe how cracked chimney flaunching behaves at your property, not just how it looks on one day.
Why cracks appear around chimney pots
The main possibilities are frost and weathering, movement of chimney pots, and poorly shaped flaunching that holds water.
Other causes worth considering are age-related cracking, and previous patching over a weak base. With cracked chimney flaunching, the important thing is to match the cause to cracks in the mortar bed around chimney pots at the top of the stack, rather than treating it as a general roofing fault. For cracked chimney flaunching, that distinction can prevent work being carried out on a nearby detail that happens to look worn but is not responsible for what you are seeing.
What you may be able to see from below
From a safe position, you can use a zoomed photograph from ground level if the top can be seen. You can also look for leaning or loose pots.
It is also useful to note whether fragments of mortar have fallen onto the roof or ground. For cracked chimney flaunching, write down what you can see and, where relevant, what the weather was doing at the time. A short sequence of photographs of cracked chimney flaunching from the same safe viewpoint can show whether the condition is changing. When checking cracked chimney flaunching, avoid walking on the roof or leaning out of windows; the aim is to collect useful information without creating another problem.
Loose pots make this more urgent
This becomes more urgent if a pot is loose, large pieces of flaunching are breaking away, and water is entering an unused or open flue. With cracked chimney flaunching, those signs suggest that waiting for a convenient time could allow more water entry, falling material or further damage.
If those warning signs are absent, cracked chimney flaunching may not need an emergency call-out, but it is still worth arranging a proper look before the condition gets worse. In this case, change over time matters: cracks in the mortar bed around chimney pots at the top of the stack that has been stable for a long period is a different situation from something that has appeared recently or is becoming more obvious after each spell of bad weather.
The whole chimney top should be checked
A roofer looking at cracked chimney flaunching should inspect the full top surface of the stack, then check pot stability before remaking the mortar.
They may also need to make sure the finished flaunching sheds water away rather than forming hollows. Because this page is about cracked chimney flaunching, the inspection should stay focused on that problem and the nearby details that could realistically produce it. For cracked chimney flaunching, ask what they think has failed, what evidence supports that view, and whether the proposed work is local or part of a wider defect. A clear explanation of cracked chimney flaunching is more useful than a quotation that simply lists materials.
Good flaunching should throw water off
Depending on what is found, a suitable repair might remove loose material before rebuilding, refix unstable pots, or form new flaunching with a proper fall away from the pots.
For cracked chimney flaunching, the best option is the one that deals with cracks in the mortar bed around chimney pots at the top of the stack and leaves the surrounding roof working as it should. If wider work is proposed for cracked chimney flaunching, ask why a local repair would not be reliable, what condition the adjoining materials are in, and whether access costs make it sensible to combine closely related repairs. The answer should make sense for cracked chimney flaunching, not read like a standard reroofing recommendation.
This guide is general information about cracked chimney flaunching. The cause of cracked chimney flaunching at an individual property can only be confirmed by inspecting the relevant roof area.