General information for homeowners, not legal, engineering or insurance advice. Permit and historic district rules vary; check with the City of Columbus Department of Building and Zoning Services or your suburb’s building department before major roof work.
You don’t need to climb on your roof to spot most slate problems, and you shouldn’t: slate is slippery and breaks easily under foot. With a pair of binoculars from the yard and a flashlight in the attic, you can see a lot. Here’s what to look for and what it usually means.
From the ground
- Gaps in the pattern. A dark spot or missing piece means a slate is gone and water can get in.
- Slipped slates. A slate hanging lower than its neighbors usually means its nails have rusted through.
- Cracked or broken corners. Often from ice, hail, branches or someone walking on the roof.
- Slate pieces in the yard or gutters. A sure sign something is coming loose up top.
- Tar or caulk patches. Black smears on the roof or around the chimney mean past quick fixes that may now be trapping water.
- Rusty or uneven valleys. The metal channels where two roof slopes meet wear out before slate does.
- Loose ridge. Missing or crooked slates or metal along the very top of the roof.
From the attic
- Water stains or dark spots on the wood under the roof
- Daylight showing through between boards
- Damp or crumbling brick around the chimney
- A musty smell after rain
Inside the house
- Ceiling stains, especially on the top floor or near a chimney
- Peeling paint or bubbling plaster on upper walls
- Drips during heavy rain or as snow melts
Signs that matter less
Color changes, lichen and a little moss are usually cosmetic on slate. Small chips on the exposed edge of a slate often do not affect how well it sheds water. A slate roofer can tell you which issues need fixing now and which can wait.
After a storm
Central Ohio gets strong summer storms and ice in winter. After a big storm, walk around the house and look for slate pieces on the ground, fallen branches on the roof and new gaps. Take photos, keep people away from areas where slate could fall, and mention any storm damage in your request.
What to do next
If you see a few missing or slipped slates, see slate roof repair. Leaks or stains point toleak repair or flashing work. Not sure? Request aninspection. Every request gets a free written estimate.