You step outside in the morning and notice a slate tile sitting on your lawn, or perhaps you spot a slightly misaligned, dark patch on your roof. It might not look like an emergency, but ignoring a single slipped slate is gambling with your ceiling.
The knock-on effect of a missing tile
Roof tiles rely on each other to maintain wind resistance. When a single slate slips, it breaks that aerodynamic seal. During the next heavy storm, the wind can get underneath the surrounding tiles, creating a tunnel effect that can strip half the roof in minutes.
Furthermore, without tile protection, rainwater falls directly onto the roofing felt underneath. Older felt becomes brittle and porous over time. Water will quickly bypass it, soak your loft insulation, and eventually pull down your bedroom ceiling.
What causes nail sickness?
In older terraced and semi-detached properties, the original roofers used iron nails to fix the slates. Over decades, condensation and weather cause these nails to rust away completely—a condition known as 'nail sickness'. When the nails perish, the heavy slates simply slide off.
Calling in a roofer
Replacing a few slipped slates is a straightforward job for an experienced roofer. They will use lead or copper 'tingles' to hook the new slates securely back into place. Expect to pay around £150 to £250 for minor roof repairs, which is vastly cheaper than treating extensive interior water damage.