Chimney Leak Repair in Connecticut

A chimney is the one part of a roof that deliberately makes a hole in it, and then stands several feet above the roofline taking weather on all four sides. Water gets in more readily here than almost anywhere else on a house, and once it is in it travels — down the inside of a stack, along a rafter, into a ceiling — before it appears as a stain somewhere that looks unrelated.

That travel is why the diagnosis matters more than the repair. A damp patch three feet from the chimney breast tells you almost nothing about the entry point on its own.

The four usual entry points are the crown, the cap, the flashing and the masonry. Each has a different repair, and each produces a slightly different pattern.

By elimination, mostly, and by looking at the top of the stack rather than at the stain. The pattern helps: water appearing in the firebox points at the cap or the flue; staining on the chimney breast at ceiling level points at the flashing; damp that comes and goes with heavy rain rather than all rain points at the masonry absorbing rather than a direct route in.

Timing helps too. A leak that started suddenly usually means something failed — a cap blown off, flashing lifted in a storm, a crown cracked over a hard winter. A leak that has crept up over years is usually masonry and mortar.

The repair then follows: the crown is repaired or recast, a cap is fitted or replaced, flashing is lifted, reset and resealed, or the masonry is repointed and, where appropriate, treated with a breathable water repellent that lets the stack dry outward while keeping rain from soaking in.