Skylight and chimney flashing repair in Medina, Ohio

Why do chimneys leak on Medina roofs?

A chimney is brick and a roof is wood, and the two move at different rates through a Medina winter. The joint between them is bridged by flashing in two parts. Step flashing lies under the shingles and turns up against the brick. Counter flashing is set into a mortar joint and folds down over the steps like a cap. Water has to get past both to reach the house.

Here is how that system breaks down.

• Counter flashing pulls out of the mortar. The joint it sits in crumbles with age, the metal tips forward, and rain runs behind it.
• Tar instead of metal. A past repair smeared roof cement over the joint. It cracks within a few seasons and hides the real condition underneath.
• No cricket on a wide chimney. A chimney on the low side of a slope acts as a dam. A small peaked saddle behind it, called a cricket, splits the water to either side. Many older chimneys never had one.
• Rusted or reused steps. When a roof was replaced on the cheap, the old step flashing was left in place and shingled over. It was already twenty years old.

Medina has plenty of chimneys to go wrong. The brick blocks around Public Square went up after the 1870 fire, and the houses built on the nearby streets in the decades after have brick chimneys of the same age, sometimes more than one. The 1990s colonials on the edges of town usually have one framed chase for a gas fireplace, sided to match the house, and that chase needs the same step flashing at every wall.

What does chimney flashing repair involve?

The shingles around the chimney come up. The old metal comes out. A strip of ice and water shield goes on the deck and up the brick. New step flashing is laid one piece per course of shingles, which is the method the City of Medina's roof guidelines call for against any vertical wall. New counter flashing is cut into a mortar joint, not surface-glued. Then the shingles go back and the joint is photographed.

We do not rebuild chimneys or repoint whole stacks. If the brick itself is failing, the photo report says so and you will want a mason before or alongside the roof work.

Why do skylights leak?

People blame the glass. It is usually something else.

• Flashing kit failure. The metal collar around the frame has corroded or was never lapped correctly into the shingles.
• Dried gaskets. On an older unit, the seal between glass and frame hardens and lets water into the frame.
• Condensation. Warm, damp bathroom air hits cold glass in January and drips. That looks like a leak and is really a ventilation problem.
• Ice at the upslope edge. Snow melts against the warm frame, refreezes below it and backs water up under the shingles.

Skylights were a popular option when Medina's subdivisions were going up in the late 1980s and 1990s. A roof window from that period is now as old as the shingles around it.

Should a skylight be repaired or replaced?

If the unit is sound and only the flashing has failed, a reflash solves it. If the glass has fogged between the panes, the frame is soft, or the unit is as old as a roof that is about to be torn off, replacement is the better spend.

A reroof is the cheapest moment to swap out an aging roof window. The shingles are already off, the opening is exposed, and the new unit and its flashing go in as part of the new roof. Putting new shingles around a thirty-year-old skylight means cutting into that new roof a few years later. When you ask for a roof replacement quote in Medina, have each skylight priced along with it, so the choice is made while the opening is exposed anyway.

What about houses near Public Square?

Addresses inside the Public Square Historic District, and designated local landmarks elsewhere in the city, need a Certificate of Appropriateness from the Historic Preservation Board before exterior work that changes how the building looks. Adding a skylight to a street-facing slope or changing chimney materials is the kind of thing the board exists to look at. Replacing hidden flashing like for like is a different matter, but ask the city's planning office first. The page on roof work near the Public Square Historic District has more.

How do you know which one is leaking?

Water runs downhill along the underside of the deck before it drops, so a stain two feet from a skylight may come from the chimney six feet above it. The owner traces the path from the attic side where he can reach it and from the roof where he cannot, then shows you the entry point in photos. That is the first step of every roof repair in Medina, and it is why the price comes after the diagnosis and not before.

If the shingles around the opening are worn out too, the report will say so. A free roof inspection covers the whole roof and rates it Good, Watch or Replace Soon, so you know whether you are fixing one joint or planning for more.