How Often Should Chimney Flashing Be Checked?

The Simple Schedule

Twice a year, from the ground and the loft. Before winter and after it. From the ground, look at the stack with the light behind you for lifted lead, open joints, missing pointing and anything sitting at an angle. From the loft, look at the timbers where the stack passes through for staining, and note the highest point any staining reaches.

Every three to five years, properly. Somebody who can actually get to it, looking at all four pieces of lead, the back gutter, the flaunching, the pointing and the brickwork. On an older or exposed property, nearer three than five.

After any storm that did damage in your street. Chimneys stand proud of the roof and take the most wind load of anything on the building.

After any work on or near the stack. Scaffolders, aerial fitters, solar installers and chimney sweeps all have reason to be near it, and flashings get disturbed.

The Interval Nobody Uses: The First Two Years

This is the Warrington-specific point, and it applies to a very large amount of housing here.

Flashing on new housing does not fail from age. It fails from having been fitted quickly, and it announces itself early rather than late - usually in the first few winters.

The recurring faults are recognisable. A cement fillet run along the junction instead of lead, because it is faster. Soakers omitted from behind a stepped flashing, so the flashing alone is doing a two-part job. A chase not raked out properly, so the lead is bedded in mastic rather than wedged into a joint. Sheets run in one continuous length rather than lapped pieces.

None of those is visible from inside the house and all of them leak eventually.

And here is the part worth acting on: if the property is inside a structural warranty period, that matters. Warranty cover on new housing typically runs for ten years with the first two normally being the builder's own responsibility to put right. Establishing exactly what is wrong in year two is a completely different conversation from noticing damp in year seven.

We will come and tell you what is wrong whether or not anybody else is paying. Knowing precisely what has failed is what makes a warranty claim go anywhere.

What to Look For From the Ground

Take a photograph with a phone at maximum zoom, from as far back as you can get with a clear view. It is easier to study a still image than to squint upward.

A dark line where the top edge of the flashing meets the brickwork means the pointing over the wedges has gone.

A visible curl or gap at the bottom edge means it has lifted.

A grey-white triangular shape at the junction rather than a stepped line of lead usually means a cement fillet.

Vegetation growing out of the stack, or a visibly dark saturated patch on one face, means the masonry is holding water.

And white streaking down the tiles below new-looking lead is patination bloom, which is cosmetic - it means the lead was fitted without patination oil rather than that anything is wrong.

On the Older Warrington Stock

The terraces at Latchford, Bewsey and Stockton Heath have tall Victorian stacks, frequently shared with the house next door, and lead that is often original.

Those want the three-year interval rather than five, and they want somebody to check the back gutter specifically - a tall stack on a slope collects debris behind it and it is the single most overlooked component on a chimney.

They also raise the shared-stack question, where a defect on the neighbour's face produces damp on your breast. Worth knowing before spending money on your own lead.